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  • Java JPA Hibernate Spring @EntityListeners throws org.springframework.dao.DataIntegrityViolationException

    - by user
    I am using Spring 3 with Hibernate 3. I would like to update the last modification date automatically when an entity is updated. Below is the sample code: HibernateConfig: @Configuration public class HibernateConfig { @Bean public DataSource dataSource() throws Exception { DriverManagerDataSource dataSource = new DriverManagerDataSource(); Properties properties = new Properties(); properties.load(ClassLoader.getSystemResourceAsStream(new String("hibernate.properties"))); dataSource.setUrl(properties.getProperty(new String("jdbc.url"))); dataSource.setUsername(properties.getProperty(new String("jdbc.username"))); dataSource.setPassword(properties.getProperty(new String("jdbc.password"))); dataSource.setDriverClassName(properties.getProperty(new String("jdbc.driverClassName"))); return dataSource; } @Bean public AnnotationSessionFactoryBean sessionFactory() throws Exception { AnnotationSessionFactoryBean sessionFactory = new AnnotationSessionFactoryBean(); Properties hibernateProperties = new Properties(); Properties properties = new Properties(); properties.load(ClassLoader.getSystemResourceAsStream(new String("hibernate.properties"))); // set the Hibernate Properties hibernateProperties.setProperty(new String("hibernate.dialect"), properties.getProperty(new String("hibernate.dialect"))); hibernateProperties.setProperty(new String("hibernate.show_sql"), properties.getProperty(new String("hibernate.show_sql"))); hibernateProperties.setProperty(new String("hibernate.hbm2ddl.auto"), properties.getProperty(new String("hibernate.hbm2ddl.auto"))); sessionFactory.setDataSource(dataSource()); sessionFactory.setHibernateProperties(hibernateProperties); sessionFactory.setAnnotatedClasses(new Class[]{Message.class}) return sessionFactory; } @Bean public HibernateTemplate hibernateTemplate() throws Exception { HibernateTemplate hibernateTemplate = new HibernateTemplate(); hibernateTemplate.setSessionFactory(sessionFactory().getObject()); return hibernateTemplate; } } DAOConfig: @Configuration public class DAOConfig { @Autowired private HibernateConfig hibernateConfig; @Bean public MessageDAO messageDAO() throws Exception { MessageDAO messageDAO = new MessageHibernateDAO(hibernateConfig.hibernateTemplate()); return messageDAO; } } Message: import java.util.Date; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.EntityListeners; import javax.persistence.Table; import javax.persistence.Temporal; import javax.persistence.TemporalType; import java.io.Serializable; import javax.persistence.Column; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; @Entity @Table @EntityListeners(value = MessageListener.class) public class Message implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column private int id; @Column(nullable = false) @Temporal(TemporalType.TIMESTAMP) private Date lastMod; public Message() { } public int getId() { return id; } public void setId(int id) { this.id = id; } public Date getLastMod() { return lastMod; } public void setLastMod(Date lastMod) { this.lastMod = lastMod; } } MessageListener: import java.util.Date; import javax.persistence.PrePersist; import javax.persistence.PreUpdate; import org.springframework.stereotype.Component; @Component public class MessageListener { @PrePersist @PreUpdate public void setLastMod(Message message) { message.setLastMod(new Date()); } } When running this the MessageListener is not being invoked. I use a DAO design pattern and when calling dao.update(Message) it throws the following Exception: org.springframework.dao.DataIntegrityViolationException: not-null property references a null or transient value: com.persistence.entities.MessageStatus.lastMod; nested exception is org.hibernate.PropertyValueException: not-null property references a null or transient value: com.persistence.entities.Message.lastMod at org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:665) at org.springframework.orm.hibernate3.HibernateAccessor.convertHibernateAccessException(HibernateAccessor.java:412) at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:411) at org.springframework.orm.hibernate3.HibernateTemplate.executeWithNativeSession(HibernateTemplate.java:374) at org.springframework.orm.hibernate3.HibernateTemplate.save(HibernateTemplate.java:683) at com.persistence.dao.hibernate.GenericHibernateDAO.save(GenericHibernateDAO.java:38) Having looked at a number of websites there seems not to be a solution.

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  • What is good practice in .NET system architecture design concerning multiple models and aggregates

    - by BuzzBubba
    I'm designing a larger enterprise architecture and I'm in a doubt about how to separate the models and design those. There are several points I'd like suggestions for: - models to define - way to define models Currently my idea is to define: Core (domain) model Repositories to get data to that domain model from a database or other store Business logic model that would contain business logic, validation logic and more specific versions of forms of data retrieval methods View models prepared for specifically formated data output that would be parsed by views of different kind (web, silverlight, etc). For the first model I'm puzzled at what to use and how to define the mode. Should this model entities contain collections and in what form? IList, IEnumerable or IQueryable collections? - I'm thinking of immutable collections which IEnumerable is, but I'd like to avoid huge data collections and to offer my Business logic layer access with LINQ expressions so that query trees get executed at Data level and retrieve only really required data for situations like the one when I'm retrieving a very specific subset of elements amongst thousands or hundreds of thousands. What if I have an item with several thousands of bids? I can't just make an IEnumerable collection of those on the model and then retrieve an item list in some Repository method or even Business model method. Should it be IQueryable so that I actually pass my queries to Repository all the way from the Business logic model layer? Should I just avoid collections in my domain model? Should I void only some collections? Should I separate Domain model and BusinessLogic model or integrate those? Data would be dealt trough repositories which would use Domain model classes. Should repositories be used directly using only classes from domain model like data containers? This is an example of what I had in mind: So, my Domain objects would look like (e.g.) public class Item { public string ItemName { get; set; } public int Price { get; set; } public bool Available { get; set; } private IList<Bid> _bids; public IQueryable<Bid> Bids { get { return _bids.AsQueryable(); } private set { _bids = value; } } public AddNewBid(Bid newBid) { _bids.Add(new Bid {.... } } Where Bid would be defined as a normal class. Repositories would be defined as data retrieval factories and used to get data into another (Business logic) model which would again be used to get data to ViewModels which would then be rendered by different consumers. I would define IQueryable interfaces for all aggregating collections to get flexibility and minimize data retrieved from real data store. Or should I make Domain Model "anemic" with pure data store entities and all collections define for business logic model? One of the most important questions is, where to have IQueryable typed collections? - All the way from Repositories to Business model or not at all and expose only solid IList and IEnumerable from Repositories and deal with more specific queries inside Business model, but have more finer grained methods for data retrieval within Repositories. So, what do you think? Have any suggestions?

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  • Inherited varibles are not reading correctly when using bitwise comparisons

    - by Shawn B
    Hey, I have a few classes set up for a game, with XMapObject as the base, and XEntity, XEnviron, and XItem inheriting it. MapObjects have a number of flags, one of them being MAPOBJECT_SOLID. My problem is, that XEntity is the only class that correctly detects MAPOBJECT_SOLID. Both Items are Environs are always considered solid by the game, regardless of the flag's state. What is important, is that Environs and Item should almost never be solid. Here are the relevent code samples: XMapObject: class XMapObject : public XObject { public: Uint8 MapObjectType,Location[2],MapObjectFlags; XMapObject *NextMapObject,*PrevMapObject; XMapObject(); void CreateMapObject(Uint8 MapObjectType); void SpawnMapObject(Uint8 MapObjectLocation[2]); void RemoveMapObject(); void DeleteMapObject(); void MapObjectSetLocation(Uint8 Y,Uint8 X); void MapObjectMapLink(); void MapObjectMapUnlink(); }; XEntity: class XEntity : public XMapObject { public: Uint8 Health,EntityFlags; float Speed,Time; XEntity *NextEntity,*PrevEntity; XItem *IventoryList; XEntity(); void CreateEntity(Uint8 EntityType,Uint8 EntityLocation[2]); void DeleteEntity(); void EntityLink(); void EntityUnlink(); Uint8 MoveEntity(Uint8 YOffset,Uint8 XOffset); }; XEnviron: class XEnviron : public XMapObject { public: Uint8 Effect,TimeOut; void CreateEnviron(Uint8 Type,Uint8 Y,Uint8 X,Uint8 TimeOut); }; XItem: class XItem : public XMapObject { public: void CreateItem(Uint8 Type,Uint8 Y,Uint8 X); }; And lastly, the entity move code. Only entities are capable of moving themselves. Uint8 XEntity::MoveEntity(Uint8 YOffset,Uint8 XOffset) { Uint8 NewY = Location[0] + YOffset, NewX = Location[1] + XOffset; if((NewY >= 0 && NewY < MAPY) && (NewX >= 0 && NewX < MAPX)) { XTile *Tile = GetTile(NewY,NewX); if(Tile->MapList != NULL) { XMapObject *MapObject = Tile->MapList; while(MapObject != NULL) { if(MapObject->MapObjectFlags & MAPOBJECT_SOLID) { printf("solid\n"); return 0; } MapObject = MapObject->NextMapObject; } } if(Tile->Flags & TILE_SOLID && EntityFlags & ENTITY_CLIPPING) { return 0; } this->MapObjectSetLocation(NewY,NewX); return 1; } return 0; } What is wierd, is that the bitwise operator always returns true when the MapObject is an Environ or an Item, but it works correctly for Entities. For debug I am using the printf "Solid", and also a printf containing the value of the flag for both Environs and Items. Any help is greatly appreciated, as this is a major bug for the small game I am working on.

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  • Foreign Key constraint violation when persisting a many-to-one class

    - by tieTYT
    I'm getting an error when trying to persist a many to one entity: Internal Exception: org.postgresql.util.PSQLException: ERROR: insert or update on table "concept" violates foreign key constraint "concept_concept_class_fk" Detail: Key (concept_class_id)=(Concept) is not present in table "concept_class". Error Code: 0 Call: INSERT INTO concept (concept_key, description, label, code, concept_class_id) VALUES (?, ?, ?, ?, ?) bind = [27, description_1, label_1, code_1, Concept] Query: InsertObjectQuery(com.mirth.results.entities.Concept[conceptKey=27]) at com.sun.ejb.containers.BaseContainer.checkExceptionClientTx(BaseContainer.java:3728) at com.sun.ejb.containers.BaseContainer.postInvokeTx(BaseContainer.java:3576) at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:1354) ... 101 more Here is the method that tries to persist it. I've put a comment where the line is: @Override public void loadConcept(String metaDataFilePath, String dataFilePath) throws Exception { try { ConceptClassMetaData conceptClassMetaData = (ConceptClassMetaData) ModelSerializer.getInstance().fromXML(FileUtils.readFileToString(new File(metaDataFilePath), "UTF8")); em.executeNativeQuery(conceptClassMetaData.getCreateStatement()); ConceptClassRow conceptClassRow = conceptClassMetaData.getConceptClassRow(); ConceptClass conceptClass = em.findByPrimaryKey(ConceptClass.class, conceptClassRow.getId()); if (conceptClass == null) { conceptClass = new ConceptClass(conceptClassRow.getId()); } conceptClass.setLabel(conceptClassRow.getLabel()); conceptClass.setOid(conceptClassRow.getOid()); conceptClass.setDescription(conceptClassRow.getDescription()); conceptClass = em.merge(conceptClass); DataParser dataParser = new DataParser(conceptClassMetaData, dataFilePath); for (ConceptModel conceptModel : dataParser.getConceptRows()) { ConceptFilter<Concept> filter = new ConceptFilter<Concept>(Concept.class); filter.setCode(conceptModel.getCode()); filter.setConceptClass(conceptClass.getLabel()); List<Concept> concepts = em.findAllByFilter(filter); Concept concept = new Concept(); if (concepts != null && !concepts.isEmpty()) { concept = concepts.get(0); } concept.setCode(conceptModel.getCode()); concept.setDescription(conceptModel.getDescription()); concept.setLabel(conceptModel.getLabel()); concept.setConceptClass(conceptClass); concept = em.merge(concept); //THIS LINE CAUSES THE ERROR! } } catch (Exception e) { e.printStackTrace(); throw e; } } ... Here are how the two entities are defined: @Entity @Table(name = "concept") @Inheritance(strategy=InheritanceType.JOINED) @DiscriminatorColumn(name="concept_class_id", discriminatorType=DiscriminatorType.STRING) public class Concept extends KanaEntity { @Id @Basic(optional = false) @Column(name = "concept_key") protected Integer conceptKey; @Basic(optional = false) @Column(name = "code") private String code; @Basic(optional = false) @Column(name = "label") private String label; @Column(name = "description") private String description; @JoinColumn(name = "concept_class_id", referencedColumnName = "id") @ManyToOne private ConceptClass conceptClass; ... @Entity @Table(name = "concept_class") public class ConceptClass extends KanaEntity { @Id @Basic(optional = false) @Column(name = "id") private String id; @Basic(optional = false) @Column(name = "label") private String label; @Column(name = "oid") private String oid; @Column(name = "description") private String description; .... And also, what's important is the sql that's being generated: INSERT INTO concept_class (id, oid, description, label) VALUES (?, ?, ?, ?) bind = [LOINC_TEST, 2.16.212.31.231.54, This is a meta data file for LOINC_TEST, loinc_test] INSERT INTO concept (concept_key, description, label, code, concept_class_id) VALUES (?, ?, ?, ?, ?) bind = [27, description_1, label_1, code_1, Concept] The reason this is failing is obvious: It's inserting the word Concept for the concept_class_id. It should be inserting the word LOINC_TEST. I can't figure out why it's using this word. I've used the debugger to look at the Concept and the ConceptClass instance and neither of them contain this word. I'm using eclipselink. Does anyone know why this is happening?

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  • Inherited variables are not reading correctly when using bitwise comparisons

    - by Shawn B
    Hey, I have a few classes set up for a game, with XMapObject as the base, and XEntity, XEnviron, and XItem inheriting it. MapObjects have a number of flags, one of them being MAPOBJECT_SOLID. My problem is that XEntity is the only class that correctly detects MAPOBJECT_SOLID. Both Items are Environs are always considered solid by the game, regardless of the flag's state. What is important is that Environs and Item should almost never be solid. Here are the relevent code samples: XMapObject: class XMapObject : public XObject { public: Uint8 MapObjectType,Location[2],MapObjectFlags; XMapObject *NextMapObject,*PrevMapObject; XMapObject(); void CreateMapObject(Uint8 MapObjectType); void SpawnMapObject(Uint8 MapObjectLocation[2]); void RemoveMapObject(); void DeleteMapObject(); void MapObjectSetLocation(Uint8 Y,Uint8 X); void MapObjectMapLink(); void MapObjectMapUnlink(); }; XEntity: class XEntity : public XMapObject { public: Uint8 Health,EntityFlags; float Speed,Time; XEntity *NextEntity,*PrevEntity; XItem *IventoryList; XEntity(); void CreateEntity(Uint8 EntityType,Uint8 EntityLocation[2]); void DeleteEntity(); void EntityLink(); void EntityUnlink(); Uint8 MoveEntity(Uint8 YOffset,Uint8 XOffset); }; XEnviron: class XEnviron : public XMapObject { public: Uint8 Effect,TimeOut; void CreateEnviron(Uint8 Type,Uint8 Y,Uint8 X,Uint8 TimeOut); }; XItem: class XItem : public XMapObject { public: void CreateItem(Uint8 Type,Uint8 Y,Uint8 X); }; And lastly, the entity move code. Only entities are capable of moving themselves. Uint8 XEntity::MoveEntity(Uint8 YOffset,Uint8 XOffset) { Uint8 NewY = Location[0] + YOffset, NewX = Location[1] + XOffset; if((NewY >= 0 && NewY < MAPY) && (NewX >= 0 && NewX < MAPX)) { XTile *Tile = GetTile(NewY,NewX); if(Tile->MapList != NULL) { XMapObject *MapObject = Tile->MapList; while(MapObject != NULL) { if(MapObject->MapObjectFlags & MAPOBJECT_SOLID) { printf("solid\n"); return 0; } MapObject = MapObject->NextMapObject; } } if(Tile->Flags & TILE_SOLID && EntityFlags & ENTITY_CLIPPING) { return 0; } this->MapObjectSetLocation(NewY,NewX); return 1; } return 0; } What is wierd, is that the bitwise operator always returns true when the MapObject is an Environ or an Item, but it works correctly for Entities. For debug I am using the printf "Solid", and also a printf containing the value of the flag for both Environs and Items. Any help is greatly appreciated, as this is a major bug for the small game I am working on.

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  • How to map an IDictionary<String, CustomCollectionType> in NHibernate

    - by devonlazarus
    Very close to what I'm trying to do but not quite the answer I think I'm looking for: How to map IDictionary<string, Entity> in Fluent NHibernate I'm trying to implement an IDictionary<String, IList<MyEntity>>and map this collection to the database using NHibernate. I do understand that you cannot map collections of collections directly in NHibernate, but I do need the functionality of accessing an ordered list of elements by key. I've implemented IUserCollectionType for my IList<MyEntity> so that I can use IDictionary<String, MyCustomCollectionType> but am struggling with how to get the map to work as I'd like. Details This is the database I'm trying to model: ------------------------ -------------------- | EntityAttributes | | Entities | ------------------------ ------------------ -------------------- | EntityAttributeId PK | | Attributes | | EntityId PK | <- | EntityId FK | ------------------ | DateCreated | | AttributeId FK | -> | AttributeId PK | -------------------- | AttributeValue | | AttributeName | ------------------------ ------------------ Here are my domain classes: public class Entity { public virtual Int32 Id { get; private set; } public virtual DateTime DateCreated { get; private set; } ... } public class EavEntity : Entity { public virtual IDictionary<String, EavEntityAttributeList> Attributes { get; protected set; } ... } public class EavAttribute : Entity { public virtual String Name { get; set; } ... } public class EavEntityAttribute : Entity { public virtual EavEntity EavEntity { get; private set; } public virtual EavAttribute EavAttribute { get; private set; } public virtual Object AttributeValue { get; set; } ... } public class EavEntityAttributeList : List<EavEntityAttribute> { } I've also implemented the NH-specific custom collection classes IUserCollectionType and PersistentList And here is my mapping so far: <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" ...> <class xmlns="urn:nhibernate-mapping-2.2" name="EavEntity" table="Entities"> <id name="Id" type="System.Int32"> <column name="EntityId" /> <generator class="identity" /> </id> ... <map cascade="all-delete-orphan" collection-type="EavEntityAttributeListType" name="EntityAttributes"> <key> <column name="EntityId" /> </key> <index type="System.String"> <column name="Name" /> </index> <one-to-many class="EavEntityAttributeList" /> </map> </class> </hibernate-mapping> I know the <map> tag is partially correct, but I'm not sure how to get NH to utilize my IUserCollectionType to persist the model to the database. What I'd like to see (and this isn't right, I know) is something like: <map cascade="all-delete-orphan" collection-type="EavEntityAttributeListType" name="EntityAttributes"> <key> <column name="EntityId" /> </key> <index type="System.String"> <column name="Name" /> </index> <list> <index column="DisplayOrder"> <one-to-many class="EntityAttributes"> </list> </map> Does anyone have any suggestions on how to properly map that IDictionary<String, EavEntityAttributeList> collection? I am using Fluent NH so I'll take examples using that library, but I'm hand mappings are just as helpful here.

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  • Foreign Key constraint when persisting a many-to-one class

    - by tieTYT
    I'm getting an error when trying to persist a many to one entity: Internal Exception: org.postgresql.util.PSQLException: ERROR: insert or update on table "concept" violates foreign key constraint "concept_concept_class_fk" Detail: Key (concept_class_id)=(Concept) is not present in table "concept_class". Error Code: 0 Call: INSERT INTO concept (concept_key, description, label, code, concept_class_id) VALUES (?, ?, ?, ?, ?) bind = [27, description_1, label_1, code_1, Concept] Query: InsertObjectQuery(com.mirth.results.entities.Concept[conceptKey=27]) at com.sun.ejb.containers.BaseContainer.checkExceptionClientTx(BaseContainer.java:3728) at com.sun.ejb.containers.BaseContainer.postInvokeTx(BaseContainer.java:3576) at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:1354) ... 101 more Here is the method that tries to persist it. I've put a comment where the line is: @Override public void loadConcept(String metaDataFilePath, String dataFilePath) throws Exception { try { ConceptClassMetaData conceptClassMetaData = (ConceptClassMetaData) ModelSerializer.getInstance().fromXML(FileUtils.readFileToString(new File(metaDataFilePath), "UTF8")); em.executeNativeQuery(conceptClassMetaData.getCreateStatement()); ConceptClassRow conceptClassRow = conceptClassMetaData.getConceptClassRow(); ConceptClass conceptClass = em.findByPrimaryKey(ConceptClass.class, conceptClassRow.getId()); if (conceptClass == null) { conceptClass = new ConceptClass(conceptClassRow.getId()); } conceptClass.setLabel(conceptClassRow.getLabel()); conceptClass.setOid(conceptClassRow.getOid()); conceptClass.setDescription(conceptClassRow.getDescription()); conceptClass = em.merge(conceptClass); DataParser dataParser = new DataParser(conceptClassMetaData, dataFilePath); for (ConceptModel conceptModel : dataParser.getConceptRows()) { ConceptFilter<Concept> filter = new ConceptFilter<Concept>(Concept.class); filter.setCode(conceptModel.getCode()); filter.setConceptClass(conceptClass.getLabel()); List<Concept> concepts = em.findAllByFilter(filter); Concept concept = new Concept(); if (concepts != null && !concepts.isEmpty()) { concept = concepts.get(0); } concept.setCode(conceptModel.getCode()); concept.setDescription(conceptModel.getDescription()); concept.setLabel(conceptModel.getLabel()); concept.setConceptClass(conceptClass); concept = em.merge(concept); //THIS LINE CAUSES THE ERROR! } } catch (Exception e) { e.printStackTrace(); throw e; } } ... Here are how the two entities are defined: @Entity @Table(name = "concept") @Inheritance(strategy=InheritanceType.JOINED) @DiscriminatorColumn(name="concept_class_id", discriminatorType=DiscriminatorType.STRING) public class Concept extends KanaEntity { @Id @Basic(optional = false) @Column(name = "concept_key") protected Integer conceptKey; @Basic(optional = false) @Column(name = "code") private String code; @Basic(optional = false) @Column(name = "label") private String label; @Column(name = "description") private String description; @JoinColumn(name = "concept_class_id", referencedColumnName = "id") @ManyToOne private ConceptClass conceptClass; ... @Entity @Table(name = "concept_class") public class ConceptClass extends KanaEntity { @Id @Basic(optional = false) @Column(name = "id") private String id; @Basic(optional = false) @Column(name = "label") private String label; @Column(name = "oid") private String oid; @Column(name = "description") private String description; .... And also, what's important is the sql that's being generated: INSERT INTO concept_class (id, oid, description, label) VALUES (?, ?, ?, ?) bind = [LOINC_TEST, 2.16.212.31.231.54, This is a meta data file for LOINC_TEST, loinc_test] INSERT INTO concept (concept_key, description, label, code, concept_class_id) VALUES (?, ?, ?, ?, ?) bind = [27, description_1, label_1, code_1, Concept] The reason this is failing is obvious: It's inserting the word Concept for the concept_class_id. It should be inserting the word LOINC_TEST. I can't figure out why it's using this word. I've used the debugger to look at the Concept and the ConceptClass instance and neither of them contain this word. I'm using eclipselink. Does anyone know why this is happening?

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  • Getting the constructor of an Interface Type through reflection, is there a better approach than loo

    - by Will Marcouiller
    I have written a generic type: IDirectorySource<T> where T : IDirectoryEntry, which I'm using to manage Active Directory entries through my interfaces objects: IGroup, IOrganizationalUnit, IUser. So that I can write the following: IDirectorySource<IGroup> groups = new DirectorySource<IGroup>(); // Where IGroup implements `IDirectoryEntry`, of course.` foreach (IGroup g in groups.ToList()) { listView1.Items.Add(g.Name).SubItems.Add(g.Description); } From the IDirectorySource<T>.ToList() methods, I use reflection to find out the appropriate constructor for the type parameter T. However, since T is given an interface type, it cannot find any constructor at all! Of course, I have an internal class Group : IGroup which implements the IGroup interface. No matter how hard I have tried, I can't figure out how to get the constructor out of my interface through my implementing class. [DirectorySchemaAttribute("group")] public interface IGroup { } internal class Group : IGroup { internal Group(DirectoryEntry entry) { NativeEntry = entry; Domain = NativeEntry.Path; } // Implementing IGroup interface... } Within the ToList() method of my IDirectorySource<T> interface implementation, I look for the constructor of T as follows: internal class DirectorySource<T> : IDirectorySource<T> { // Implementing properties... // Methods implementations... public IList<T> ToList() { Type t = typeof(T) // Let's assume we're always working with the IGroup interface as T here to keep it simple. // So, my `DirectorySchema` property is already set to "group". // My `DirectorySearcher` is already instantiated here, as I do it within the DirectorySource<T> constructor. Searcher.Filter = string.Format("(&(objectClass={0}))", DirectorySchema) ConstructorInfo ctor = null; ParameterInfo[] params = null; // This is where I get stuck for now... Please see the helper method. GetConstructor(out ctor, out params, new Type() { DirectoryEntry }); SearchResultCollection results = null; try { results = Searcher.FindAll(); } catch (DirectoryServicesCOMException ex) { // Handling exception here... } foreach (SearchResult entry in results) entities.Add(ctor.Invoke(new object() { entry.GetDirectoryEntry() })); return entities; } } private void GetConstructor(out ConstructorInfo constructor, out ParameterInfo[] parameters, Type paramsTypes) { Type t = typeof(T); ConstructorInfo[] ctors = t.GetConstructors(BindingFlags.CreateInstance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.InvokeMethod); bool found = true; foreach (ContructorInfo c in ctors) { parameters = c.GetParameters(); if (parameters.GetLength(0) == paramsTypes.GetLength(0)) { for (int index = 0; index < parameters.GetLength(0); ++index) { if (!(parameters[index].GetType() is paramsTypes[index].GetType())) found = false; } if (found) { constructor = c; return; } } } // Processing constructor not found message here... } My problem is that T will always be an interface, so it never finds a constructor. Is there a better way than looping through all of my assembly types for implementations of my interface? I don't care about rewriting a piece of my code, I want to do it right on the first place so that I won't need to come back again and again and again. EDIT #1 Following Sam's advice, I will for now go with the IName and Name convention. However, is it me or there's some way to improve my code? Thanks! =)

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  • Entity with Guid ID is not inserted by NHibernate

    - by DanK
    I am experimenting with NHibernate (version 2.1.0.4000) with Fluent NHibernate Automapping. My test set of entities persists fine with default integer IDs I am now trying to use Guid IDs with the entities. Unfortunately changing the Id property to a Guid seems to stop NHibernate inserting objects. Here is the entity class: public class User { public virtual int Id { get; private set; } public virtual string FirstName { get; set; } public virtual string LastName { get; set; } public virtual string Email { get; set; } public virtual string Password { get; set; } public virtual List<UserGroup> Groups { get; set; } } And here is the Fluent NHibernate configuration I am using: SessionFactory = Fluently.Configure() //.Database(SQLiteConfiguration.Standard.InMemory) .Database(MsSqlConfiguration.MsSql2008.ConnectionString(@"Data Source=.\SQLEXPRESS;Initial Catalog=NHibernateTest;Uid=NHibernateTest;Password=password").ShowSql()) .Mappings(m => m.AutoMappings.Add( AutoMap.AssemblyOf<TestEntities.User>() .UseOverridesFromAssemblyOf<UserGroupMappingOverride>())) .ExposeConfiguration(x => { x.SetProperty("current_session_context_class","web"); }) .ExposeConfiguration(Cfg => _configuration = Cfg) .BuildSessionFactory(); Here is the log output when using an integer ID: 16:23:14.287 [4] DEBUG NHibernate.Event.Default.DefaultSaveOrUpdateEventListener - saving transient instance 16:23:14.291 [4] DEBUG NHibernate.Event.Default.AbstractSaveEventListener - saving [TestEntities.User#<null>] 16:23:14.299 [4] DEBUG NHibernate.Event.Default.AbstractSaveEventListener - executing insertions 16:23:14.309 [4] DEBUG NHibernate.Event.Default.AbstractSaveEventListener - executing identity-insert immediately 16:23:14.313 [4] DEBUG NHibernate.Persister.Entity.AbstractEntityPersister - Inserting entity: TestEntities.User (native id) 16:23:14.321 [4] DEBUG NHibernate.AdoNet.AbstractBatcher - Opened new IDbCommand, open IDbCommands: 1 16:23:14.321 [4] DEBUG NHibernate.AdoNet.AbstractBatcher - Building an IDbCommand object for the SqlString: INSERT INTO [User] (FirstName, LastName, Email, Password) VALUES (?, ?, ?, ?); select SCOPE_IDENTITY() 16:23:14.322 [4] DEBUG NHibernate.Persister.Entity.AbstractEntityPersister - Dehydrating entity: [TestEntities.User#<null>] 16:23:14.323 [4] DEBUG NHibernate.Type.StringType - binding null to parameter: 0 16:23:14.323 [4] DEBUG NHibernate.Type.StringType - binding null to parameter: 1 16:23:14.323 [4] DEBUG NHibernate.Type.StringType - binding 'ertr' to parameter: 2 16:23:14.324 [4] DEBUG NHibernate.Type.StringType - binding 'tretret' to parameter: 3 16:23:14.329 [4] DEBUG NHibernate.SQL - INSERT INTO [User] (FirstName, LastName, Email, Password) VALUES (@p0, @p1, @p2, @p3); select SCOPE_IDENTITY();@p0 = NULL, @p1 = NULL, @p2 = 'ertr', @p3 = 'tretret' and here is the output when using a Guid: 16:50:14.008 [4] DEBUG NHibernate.Event.Default.DefaultSaveOrUpdateEventListener - saving transient instance 16:50:14.012 [4] DEBUG NHibernate.Event.Default.AbstractSaveEventListener - generated identifier: d74e1bd3-1c01-46c8-996c-9d370115780d, using strategy: NHibernate.Id.GuidCombGenerator 16:50:14.013 [4] DEBUG NHibernate.Event.Default.AbstractSaveEventListener - saving [TestEntities.User#d74e1bd3-1c01-46c8-996c-9d370115780d] This is where it silently fails, with no exception thrown or further log entries. It looks like it is generating the Guid ID correctly for the new object, but is just not getting any further than that. Is there something I need to do differently in order to use Guid IDs? Thanks, Dan.

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  • How do I get a delete trigger working using fluent API in CTP5?

    - by user668472
    I am having trouble getting referential integrity dialled down enough to allow my delete trigger to fire. I have a dependent entity with three FKs. I want it to be deleted when any of the principal entities is deleted. For principal entities Role and OrgUnit (see below) I can rely on conventions to create the required one-many relationship and cascade delete does what I want, ie: Association is removed when either principal is deleted. For Member, however, I have multiple cascade delete paths (not shown here) which SQL Server doesn't like, so I need to use fluent API to disable cascade deletes. Here is my (simplified) model: public class Association { public int id { get; set; } public int roleid { get; set; } public virtual Role role { get; set; } public int? memberid { get; set; } public virtual Member member { get; set; } public int orgunitid { get; set; } public int OrgUnit orgunit { get; set; } } public class Role { public int id { get; set; } public virtual ICollection<Association> associations { get; set; } } public class Member { public int id { get; set; } public virtual ICollection<Association> associations { get; set; } } public class Organization { public int id { get; set; } public virtual ICollection<Association> associations { get; set; } } My first run at fluent API code looks like this: protected override void OnModelCreating(System.Data.Entity.ModelConfiguration.ModelBuilder modelBuilder) { DbDatabase.SetInitializer<ConfDB_Model>(new ConfDBInitializer()); modelBuilder.Entity<Member>() .HasMany(m=>m.assocations) .WithOptional(a=>a.member) .HasForeignKey(a=>a.memberId) .WillCascadeOnDelete(false); } My seed function creates the delete trigger: protected override void Seed(ConfDB_Model context) { context.Database.SqlCommand("CREATE TRIGGER MemberAssocTrigger ON dbo.Members FOR DELETE AS DELETE Assocations FROM Associations, deleted WHERE Associations.memberId = deleted.id"); } PROBLEM: When I run this, create a Role, a Member, an OrgUnit, and an Association tying the three together all is fine. When I delete the Role, the Association gets cascade deleted as I expect. HOWEVER when I delete the Member I get an exception with a referential integrity error. I have tried setting ON CASCADE SET NULL because my memberid FK is nullable but SQL complains again about multiple cascade paths, so apparently I can cascade nothing in the Member-Association relationship. To get this to work I must add the following code to Seed(): context.Database.SqlCommand("ALTER TABLE dbo.ACLEntries DROP CONSTRAINT member_aclentries"); As you can see, this drops the constraint created by the model builder. QUESTION: this feels like a complete hack. Is there a way using fluent API for me to say that referential integrity should NOT be checked, or otherwise to get it to relax enough for the Member delete to work and allow the trigger to be fired? Thanks in advance for any help you can offer. Although fluent APIs may be "fluent" I find them far from intuitive.

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  • Getting the constructor of an Interface Type through reflection?

    - by Will Marcouiller
    I have written a generic type: IDirectorySource<T> where T : IDirectoryEntry, which I'm using to manage Active Directory entries through my interfaces objects: IGroup, IOrganizationalUnit, IUser. So that I can write the following: IDirectorySource<IGroup> groups = new DirectorySource<IGroup>(); // Where IGroup implements `IDirectoryEntry`, of course.` foreach (IGroup g in groups.ToList()) { listView1.Items.Add(g.Name).SubItems.Add(g.Description); } From the IDirectorySource<T>.ToList() methods, I use reflection to find out the appropriate constructor for the type parameter T. However, since T is given an interface type, it cannot find any constructor at all! Of course, I have an internal class Group : IGroup which implements the IGroup interface. No matter how hard I have tried, I can't figure out how to get the constructor out of my interface through my implementing class. [DirectorySchemaAttribute("group")] public interface IGroup { } internal class Group : IGroup { internal Group(DirectoryEntry entry) { NativeEntry = entry; Domain = NativeEntry.Path; } // Implementing IGroup interface... } Within the ToList() method of my IDirectorySource<T> interface implementation, I look for the constructor of T as follows: internal class DirectorySource<T> : IDirectorySource<T> { // Implementing properties... // Methods implementations... public IList<T> ToList() { Type t = typeof(T) // Let's assume we're always working with the IGroup interface as T here to keep it simple. // So, my `DirectorySchema` property is already set to "group". // My `DirectorySearcher` is already instantiated here, as I do it within the DirectorySource<T> constructor. Searcher.Filter = string.Format("(&(objectClass={0}))", DirectorySchema) ConstructorInfo ctor = null; ParameterInfo[] params = null; // This is where I get stuck for now... Please see the helper method. GetConstructor(out ctor, out params, new Type() { DirectoryEntry }); SearchResultCollection results = null; try { results = Searcher.FindAll(); } catch (DirectoryServicesCOMException ex) { // Handling exception here... } foreach (SearchResult entry in results) entities.Add(ctor.Invoke(new object() { entry.GetDirectoryEntry() })); return entities; } } private void GetConstructor(out ConstructorInfo constructor, out ParameterInfo[] parameters, Type paramsTypes) { Type t = typeof(T); ConstructorInfo[] ctors = t.GetConstructors(BindingFlags.CreateInstance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.InvokeMethod); bool found = true; foreach (ContructorInfo c in ctors) { parameters = c.GetParameters(); if (parameters.GetLength(0) == paramsTypes.GetLength(0)) { for (int index = 0; index < parameters.GetLength(0); ++index) { if (!(parameters[index].GetType() is paramsTypes[index].GetType())) found = false; } if (found) { constructor = c; return; } } } // Processing constructor not found message here... } My problem is that T will always be an interface, so it never finds a constructor. Might somebody guide me to the right path to follow in this situation?

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  • If I use a facade class with generic methods to access the JPA API, how should I provide additional processing for specific types?

    - by Shaun
    Let's say I'm making a fairly simple web application using JAVA EE specs (I've heard this is possible). In this app, I only have about 10 domain/data objects, and these are represented by JPA Entities. Architecturally, I would consider the JPA API to perform the role of a DAO. Of course, I don't want to use the EntityManager directly in my UI (JSF) and I need to manage transactions, so I delegate these tasks to the so-called service layer. More specifically, I would like to be able to handle these tasks in a single DataService class (often also called CrudService) with generic methods. See this article by Adam Bien for an example interface: http://www.adam-bien.com/roller/abien/entry/generic_crud_service_aka_dao My project differs from that article in that I can't use EJBs, so my service classes are essentially just named beans and I handle transactions manually. Regardless, what I want is a single interface for simple CRUD operations on my data objects because having a different class for each data type would lead to a lot of duplicate and/or unnecessary code. Ideally, my views would be able to use a method such as public <T> List<T> findAll(Class<T> type) { ... } to retrieve data. Using JSF, it might look something like this: <h:dataTable value="#{dataService.findAll(data.class)}" var="d"> ... </h:dataTable> Similarly, after validating forms, my controller could submit the data with a method such as: public <T> void add(T entity) { ... } Granted, you'd probably actually want to return something useful to the caller. In any case, this works well if your data can be treated as homogenous in this manner. Alas, it breaks down when you need to perform additional processing on certain objects before passing them on to JPA. For example, let's say I'm dealing with Books and Authors which have a many-to-many relationship. Each Book has a set of IDs referring to its authors, and each Author has a set of IDs referring to their books. Normally, JPA can manage this kind of relationship for you, but in some cases it can't (for example, the google app engine JPA provider doesn't support this). Thus, when I persist a new book for example, I may need to update the corresponding author entities. My question, then, is if there's an elegant way to handle this or if I should reconsider the sanity of my whole design. Here's a couple ways I see of dealing with it: The instanceof operator. I could use this to target certain classes when special processing is needed. Perhaps maintainability suffers and it isn't beautiful code, but if there's only 10 or so domain objects it can't be all that bad... could it? Make a different service for each entity type (ie, BookService and AuthorService). All services would inherit from a generic DataService base class and override methods if special processing is needed. At this point, you could probably also just call them DAOs instead. As always, I appreciate the help. Let me know if any clarifications are needed, as I left out many smaller details.

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  • Is there a Telecommunications Reference Architecture?

    - by raul.goycoolea
    @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Abstract   Reference architecture provides needed architectural information that can be provided in advance to an enterprise to enable consistent architectural best practices. Enterprise Reference Architecture helps business owners to actualize their strategies, vision, objectives, and principles. It evaluates the IT systems, based on Reference Architecture goals, principles, and standards. It helps to reduce IT costs by increasing functionality, availability, scalability, etc. Telecom Reference Architecture provides customers with the flexibility to view bundled service bills online with the provision of multiple services. It provides real-time, flexible billing and charging systems, to handle complex promotions, discounts, and settlements with multiple parties. This paper attempts to describe the Reference Architecture for the Telecom Enterprises. It lays the foundation for a Telecom Reference Architecture by articulating the requirements, drivers, and pitfalls for telecom service providers. It describes generic reference architecture for telecom enterprises and moves on to explain how to achieve Enterprise Reference Architecture by using SOA.   Introduction   A Reference Architecture provides a methodology, set of practices, template, and standards based on a set of successful solutions implemented earlier. These solutions have been generalized and structured for the depiction of both a logical and a physical architecture, based on the harvesting of a set of patterns that describe observations in a number of successful implementations. It helps as a reference for the various architectures that an enterprise can implement to solve various problems. It can be used as the starting point or the point of comparisons for various departments/business entities of a company, or for the various companies for an enterprise. It provides multiple views for multiple stakeholders.   Major artifacts of the Enterprise Reference Architecture are methodologies, standards, metadata, documents, design patterns, etc.   Purpose of Reference Architecture   In most cases, architects spend a lot of time researching, investigating, defining, and re-arguing architectural decisions. It is like reinventing the wheel as their peers in other organizations or even the same organization have already spent a lot of time and effort defining their own architectural practices. This prevents an organization from learning from its own experiences and applying that knowledge for increased effectiveness.   Reference architecture provides missing architectural information that can be provided in advance to project team members to enable consistent architectural best practices.   Enterprise Reference Architecture helps an enterprise to achieve the following at the abstract level:   ·       Reference architecture is more of a communication channel to an enterprise ·       Helps the business owners to accommodate to their strategies, vision, objectives, and principles. ·       Evaluates the IT systems based on Reference Architecture Principles ·       Reduces IT spending through increasing functionality, availability, scalability, etc ·       A Real-time Integration Model helps to reduce the latency of the data updates Is used to define a single source of Information ·       Provides a clear view on how to manage information and security ·       Defines the policy around the data ownership, product boundaries, etc. ·       Helps with cost optimization across project and solution portfolios by eliminating unused or duplicate investments and assets ·       Has a shorter implementation time and cost   Once the reference architecture is in place, the set of architectural principles, standards, reference models, and best practices ensure that the aligned investments have the greatest possible likelihood of success in both the near term and the long term (TCO).     Common pitfalls for Telecom Service Providers   Telecom Reference Architecture serves as the first step towards maturity for a telecom service provider. During the course of our assignments/experiences with telecom players, we have come across the following observations – Some of these indicate a lack of maturity of the telecom service provider:   ·       In markets that are growing and not so mature, it has been observed that telcos have a significant amount of in-house or home-grown applications. In some of these markets, the growth has been so rapid that IT has been unable to cope with business demands. Telcos have shown a tendency to come up with workarounds in their IT applications so as to meet business needs. ·       Even for core functions like provisioning or mediation, some telcos have tried to manage with home-grown applications. ·       Most of the applications do not have the required scalability or maintainability to sustain growth in volumes or functionality. ·       Applications face interoperability issues with other applications in the operator's landscape. Integrating a new application or network element requires considerable effort on the part of the other applications. ·       Application boundaries are not clear, and functionality that is not in the initial scope of that application gets pushed onto it. This results in the development of the multiple, small applications without proper boundaries. ·       Usage of Legacy OSS/BSS systems, poor Integration across Multiple COTS Products and Internal Systems. Most of the Integrations are developed on ad-hoc basis and Point-to-Point Integration. ·       Redundancy of the business functions in different applications • Fragmented data across the different applications and no integrated view of the strategic data • Lot of performance Issues due to the usage of the complex integration across OSS and BSS systems   However, this is where the maturity of the telecom industry as a whole can be of help. The collaborative efforts of telcos to overcome some of these problems have resulted in bodies like the TM Forum. They have come up with frameworks for business processes, data, applications, and technology for telecom service providers. These could be a good starting point for telcos to clean up their enterprise landscape.   Industry Trends in Telecom Reference Architecture   Telecom reference architectures are evolving rapidly because telcos are facing business and IT challenges.   “The reality is that there probably is no killer application, no silver bullet that the telcos can latch onto to carry them into a 21st Century.... Instead, there are probably hundreds – perhaps thousands – of niche applications.... And the only way to find which of these works for you is to try out lots of them, ramp up the ones that work, and discontinue the ones that fail.” – Martin Creaner President & CTO TM Forum.   The following trends have been observed in telecom reference architecture:   ·       Transformation of business structures to align with customer requirements ·       Adoption of more Internet-like technical architectures. The Web 2.0 concept is increasingly being used. ·       Virtualization of the traditional operations support system (OSS) ·       Adoption of SOA to support development of IP-based services ·       Adoption of frameworks like Service Delivery Platforms (SDPs) and IP Multimedia Subsystem ·       (IMS) to enable seamless deployment of various services over fixed and mobile networks ·       Replacement of in-house, customized, and stove-piped OSS/BSS with standards-based COTS products ·       Compliance with industry standards and frameworks like eTOM, SID, and TAM to enable seamless integration with other standards-based products   Drivers of Reference Architecture   The drivers of the Reference Architecture are Reference Architecture Goals, Principles, and Enterprise Vision and Telecom Transformation. The details are depicted below diagram. @font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoCaption, li.MsoCaption, div.MsoCaption { margin: 0cm 0cm 10pt; font-size: 9pt; font-family: "Times New Roman"; color: rgb(79, 129, 189); font-weight: bold; }div.Section1 { page: Section1; } Figure 1. Drivers for Reference Architecture @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Today’s telecom reference architectures should seamlessly integrate traditional legacy-based applications and transition to next-generation network technologies (e.g., IP multimedia subsystems). This has resulted in new requirements for flexible, real-time billing and OSS/BSS systems and implications on the service provider’s organizational requirements and structure.   Telecom reference architectures are today expected to:   ·       Integrate voice, messaging, email and other VAS over fixed and mobile networks, back end systems ·       Be able to provision multiple services and service bundles • Deliver converged voice, video and data services ·       Leverage the existing Network Infrastructure ·       Provide real-time, flexible billing and charging systems to handle complex promotions, discounts, and settlements with multiple parties. ·       Support charging of advanced data services such as VoIP, On-Demand, Services (e.g.  Video), IMS/SIP Services, Mobile Money, Content Services and IPTV. ·       Help in faster deployment of new services • Serve as an effective platform for collaboration between network IT and business organizations ·       Harness the potential of converging technology, networks, devices and content to develop multimedia services and solutions of ever-increasing sophistication on a single Internet Protocol (IP) ·       Ensure better service delivery and zero revenue leakage through real-time balance and credit management ·       Lower operating costs to drive profitability   Enterprise Reference Architecture   The Enterprise Reference Architecture (RA) fills the gap between the concepts and vocabulary defined by the reference model and the implementation. Reference architecture provides detailed architectural information in a common format such that solutions can be repeatedly designed and deployed in a consistent, high-quality, supportable fashion. This paper attempts to describe the Reference Architecture for the Telecom Application Usage and how to achieve the Enterprise Level Reference Architecture using SOA.   • Telecom Reference Architecture • Enterprise SOA based Reference Architecture   Telecom Reference Architecture   Tele Management Forum’s New Generation Operations Systems and Software (NGOSS) is an architectural framework for organizing, integrating, and implementing telecom systems. NGOSS is a component-based framework consisting of the following elements:   ·       The enhanced Telecom Operations Map (eTOM) is a business process framework. ·       The Shared Information Data (SID) model provides a comprehensive information framework that may be specialized for the needs of a particular organization. ·       The Telecom Application Map (TAM) is an application framework to depict the functional footprint of applications, relative to the horizontal processes within eTOM. ·       The Technology Neutral Architecture (TNA) is an integrated framework. TNA is an architecture that is sustainable through technology changes.   NGOSS Architecture Standards are:   ·       Centralized data ·       Loosely coupled distributed systems ·       Application components/re-use  ·       A technology-neutral system framework with technology specific implementations ·       Interoperability to service provider data/processes ·       Allows more re-use of business components across multiple business scenarios ·       Workflow automation   The traditional operator systems architecture consists of four layers,   ·       Business Support System (BSS) layer, with focus toward customers and business partners. Manages order, subscriber, pricing, rating, and billing information. ·       Operations Support System (OSS) layer, built around product, service, and resource inventories. ·       Networks layer – consists of Network elements and 3rd Party Systems. ·       Integration Layer – to maximize application communication and overall solution flexibility.   Reference architecture for telecom enterprises is depicted below. @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoCaption, li.MsoCaption, div.MsoCaption { margin: 0cm 0cm 10pt; font-size: 9pt; font-family: "Times New Roman"; color: rgb(79, 129, 189); font-weight: bold; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Figure 2. Telecom Reference Architecture   The major building blocks of any Telecom Service Provider architecture are as follows:   1. Customer Relationship Management   CRM encompasses the end-to-end lifecycle of the customer: customer initiation/acquisition, sales, ordering, and service activation, customer care and support, proactive campaigns, cross sell/up sell, and retention/loyalty.   CRM also includes the collection of customer information and its application to personalize, customize, and integrate delivery of service to a customer, as well as to identify opportunities for increasing the value of the customer to the enterprise.   The key functionalities related to Customer Relationship Management are   ·       Manage the end-to-end lifecycle of a customer request for products. ·       Create and manage customer profiles. ·       Manage all interactions with customers – inquiries, requests, and responses. ·       Provide updates to Billing and other south bound systems on customer/account related updates such as customer/ account creation, deletion, modification, request bills, final bill, duplicate bills, credit limits through Middleware. ·       Work with Order Management System, Product, and Service Management components within CRM. ·       Manage customer preferences – Involve all the touch points and channels to the customer, including contact center, retail stores, dealers, self service, and field service, as well as via any media (phone, face to face, web, mobile device, chat, email, SMS, mail, the customer's bill, etc.). ·       Support single interface for customer contact details, preferences, account details, offers, customer premise equipment, bill details, bill cycle details, and customer interactions.   CRM applications interact with customers through customer touch points like portals, point-of-sale terminals, interactive voice response systems, etc. The requests by customers are sent via fulfillment/provisioning to billing system for ordering processing.   2. Billing and Revenue Management   Billing and Revenue Management handles the collection of appropriate usage records and production of timely and accurate bills – for providing pre-bill usage information and billing to customers; for processing their payments; and for performing payment collections. In addition, it handles customer inquiries about bills, provides billing inquiry status, and is responsible for resolving billing problems to the customer's satisfaction in a timely manner. This process grouping also supports prepayment for services.   The key functionalities provided by these applications are   ·       To ensure that enterprise revenue is billed and invoices delivered appropriately to customers. ·       To manage customers’ billing accounts, process their payments, perform payment collections, and monitor the status of the account balance. ·       To ensure the timely and effective fulfillment of all customer bill inquiries and complaints. ·       Collect the usage records from mediation and ensure appropriate rating and discounting of all usage and pricing. ·       Support revenue sharing; split charging where usage is guided to an account different from the service consumer. ·       Support prepaid and post-paid rating. ·       Send notification on approach / exceeding the usage thresholds as enforced by the subscribed offer, and / or as setup by the customer. ·       Support prepaid, post paid, and hybrid (where some services are prepaid and the rest of the services post paid) customers and conversion from post paid to prepaid, and vice versa. ·       Support different billing function requirements like charge prorating, promotion, discount, adjustment, waiver, write-off, account receivable, GL Interface, late payment fee, credit control, dunning, account or service suspension, re-activation, expiry, termination, contract violation penalty, etc. ·       Initiate direct debit to collect payment against an invoice outstanding. ·       Send notification to Middleware on different events; for example, payment receipt, pre-suspension, threshold exceed, etc.   Billing systems typically get usage data from mediation systems for rating and billing. They get provisioning requests from order management systems and inquiries from CRM systems. Convergent and real-time billing systems can directly get usage details from network elements.   3. Mediation   Mediation systems transform/translate the Raw or Native Usage Data Records into a general format that is acceptable to billing for their rating purposes.   The following lists the high-level roles and responsibilities executed by the Mediation system in the end-to-end solution.   ·       Collect Usage Data Records from different data sources – like network elements, routers, servers – via different protocol and interfaces. ·       Process Usage Data Records – Mediation will process Usage Data Records as per the source format. ·       Validate Usage Data Records from each source. ·       Segregates Usage Data Records coming from each source to multiple, based on the segregation requirement of end Application. ·       Aggregates Usage Data Records based on the aggregation rule if any from different sources. ·       Consolidates multiple Usage Data Records from each source. ·       Delivers formatted Usage Data Records to different end application like Billing, Interconnect, Fraud Management, etc. ·       Generates audit trail for incoming Usage Data Records and keeps track of all the Usage Data Records at various stages of mediation process. ·       Checks duplicate Usage Data Records across files for a given time window.   4. Fulfillment   This area is responsible for providing customers with their requested products in a timely and correct manner. It translates the customer's business or personal need into a solution that can be delivered using the specific products in the enterprise's portfolio. This process informs the customers of the status of their purchase order, and ensures completion on time, as well as ensuring a delighted customer. These processes are responsible for accepting and issuing orders. They deal with pre-order feasibility determination, credit authorization, order issuance, order status and tracking, customer update on customer order activities, and customer notification on order completion. Order management and provisioning applications fall into this category.   The key functionalities provided by these applications are   ·       Issuing new customer orders, modifying open customer orders, or canceling open customer orders; ·       Verifying whether specific non-standard offerings sought by customers are feasible and supportable; ·       Checking the credit worthiness of customers as part of the customer order process; ·       Testing the completed offering to ensure it is working correctly; ·       Updating of the Customer Inventory Database to reflect that the specific product offering has been allocated, modified, or cancelled; ·       Assigning and tracking customer provisioning activities; ·       Managing customer provisioning jeopardy conditions; and ·       Reporting progress on customer orders and other processes to customer.   These applications typically get orders from CRM systems. They interact with network elements and billing systems for fulfillment of orders.   5. Enterprise Management   This process area includes those processes that manage enterprise-wide activities and needs, or have application within the enterprise as a whole. They encompass all business management processes that   ·       Are necessary to support the whole of the enterprise, including processes for financial management, legal management, regulatory management, process, cost, and quality management, etc.;   ·       Are responsible for setting corporate policies, strategies, and directions, and for providing guidelines and targets for the whole of the business, including strategy development and planning for areas, such as Enterprise Architecture, that are integral to the direction and development of the business;   ·       Occur throughout the enterprise, including processes for project management, performance assessments, cost assessments, etc.     (i) Enterprise Risk Management:   Enterprise Risk Management focuses on assuring that risks and threats to the enterprise value and/or reputation are identified, and appropriate controls are in place to minimize or eliminate the identified risks. The identified risks may be physical or logical/virtual. Successful risk management ensures that the enterprise can support its mission critical operations, processes, applications, and communications in the face of serious incidents such as security threats/violations and fraud attempts. Two key areas covered in Risk Management by telecom operators are:   ·       Revenue Assurance: Revenue assurance system will be responsible for identifying revenue loss scenarios across components/systems, and will help in rectifying the problems. The following lists the high-level roles and responsibilities executed by the Revenue Assurance system in the end-to-end solution. o   Identify all usage information dropped when networks are being upgraded. o   Interconnect bill verification. o   Identify where services are routinely provisioned but never billed. o   Identify poor sales policies that are intensifying collections problems. o   Find leakage where usage is sent to error bucket and never billed for. o   Find leakage where field service, CRM, and network build-out are not optimized.   ·       Fraud Management: Involves collecting data from different systems to identify abnormalities in traffic patterns, usage patterns, and subscription patterns to report suspicious activity that might suggest fraudulent usage of resources, resulting in revenue losses to the operator.   The key roles and responsibilities of the system component are as follows:   o   Fraud management system will capture and monitor high usage (over a certain threshold) in terms of duration, value, and number of calls for each subscriber. The threshold for each subscriber is decided by the system and fixed automatically. o   Fraud management will be able to detect the unauthorized access to services for certain subscribers. These subscribers may have been provided unauthorized services by employees. The component will raise the alert to the operator the very first time of such illegal calls or calls which are not billed. o   The solution will be to have an alarm management system that will deliver alarms to the operator/provider whenever it detects a fraud, thus minimizing fraud by catching it the first time it occurs. o   The Fraud Management system will be capable of interfacing with switches, mediation systems, and billing systems   (ii) Knowledge Management   This process focuses on knowledge management, technology research within the enterprise, and the evaluation of potential technology acquisitions.   Key responsibilities of knowledge base management are to   ·       Maintain knowledge base – Creation and updating of knowledge base on ongoing basis. ·       Search knowledge base – Search of knowledge base on keywords or category browse ·       Maintain metadata – Management of metadata on knowledge base to ensure effective management and search. ·       Run report generator. ·       Provide content – Add content to the knowledge base, e.g., user guides, operational manual, etc.   (iii) Document Management   It focuses on maintaining a repository of all electronic documents or images of paper documents relevant to the enterprise using a system.   (iv) Data Management   It manages data as a valuable resource for any enterprise. For telecom enterprises, the typical areas covered are Master Data Management, Data Warehousing, and Business Intelligence. It is also responsible for data governance, security, quality, and database management.   Key responsibilities of Data Management are   ·       Using ETL, extract the data from CRM, Billing, web content, ERP, campaign management, financial, network operations, asset management info, customer contact data, customer measures, benchmarks, process data, e.g., process inputs, outputs, and measures, into Enterprise Data Warehouse. ·       Management of data traceability with source, data related business rules/decisions, data quality, data cleansing data reconciliation, competitors data – storage for all the enterprise data (customer profiles, products, offers, revenues, etc.) ·       Get online update through night time replication or physical backup process at regular frequency. ·       Provide the data access to business intelligence and other systems for their analysis, report generation, and use.   (v) Business Intelligence   It uses the Enterprise Data to provide the various analysis and reports that contain prospects and analytics for customer retention, acquisition of new customers due to the offers, and SLAs. It will generate right and optimized plans – bolt-ons for the customers.   The following lists the high-level roles and responsibilities executed by the Business Intelligence system at the Enterprise Level:   ·       It will do Pattern analysis and reports problem. ·       It will do Data Analysis – Statistical analysis, data profiling, affinity analysis of data, customer segment wise usage patterns on offers, products, service and revenue generation against services and customer segments. ·       It will do Performance (business, system, and forecast) analysis, churn propensity, response time, and SLAs analysis. ·       It will support for online and offline analysis, and report drill down capability. ·       It will collect, store, and report various SLA data. ·       It will provide the necessary intelligence for marketing and working on campaigns, etc., with cost benefit analysis and predictions.   It will advise on customer promotions with additional services based on loyalty and credit history of customer   ·       It will Interface with Enterprise Data Management system for data to run reports and analysis tasks. It will interface with the campaign schedules, based on historical success evidence.   (vi) Stakeholder and External Relations Management   It manages the enterprise's relationship with stakeholders and outside entities. Stakeholders include shareholders, employee organizations, etc. Outside entities include regulators, local community, and unions. Some of the processes within this grouping are Shareholder Relations, External Affairs, Labor Relations, and Public Relations.   (vii) Enterprise Resource Planning   It is used to manage internal and external resources, including tangible assets, financial resources, materials, and human resources. Its purpose is to facilitate the flow of information between all business functions inside the boundaries of the enterprise and manage the connections to outside stakeholders. ERP systems consolidate all business operations into a uniform and enterprise wide system environment.   The key roles and responsibilities for Enterprise System are given below:   ·        It will handle responsibilities such as core accounting, financial, and management reporting. ·       It will interface with CRM for capturing customer account and details. ·       It will interface with billing to capture the billing revenue and other financial data. ·       It will be responsible for executing the dunning process. Billing will send the required feed to ERP for execution of dunning. ·       It will interface with the CRM and Billing through batch interfaces. Enterprise management systems are like horizontals in the enterprise and typically interact with all major telecom systems. E.g., an ERP system interacts with CRM, Fulfillment, and Billing systems for different kinds of data exchanges.   6. External Interfaces/Touch Points   The typical external parties are customers, suppliers/partners, employees, shareholders, and other stakeholders. External interactions from/to a Service Provider to other parties can be achieved by a variety of mechanisms, including:   ·       Exchange of emails or faxes ·       Call Centers ·       Web Portals ·       Business-to-Business (B2B) automated transactions   These applications provide an Internet technology driven interface to external parties to undertake a variety of business functions directly for themselves. These can provide fully or partially automated service to external parties through various touch points.   Typical characteristics of these touch points are   ·       Pre-integrated self-service system, including stand-alone web framework or integration front end with a portal engine ·       Self services layer exposing atomic web services/APIs for reuse by multiple systems across the architectural environment ·       Portlets driven connectivity exposing data and services interoperability through a portal engine or web application   These touch points mostly interact with the CRM systems for requests, inquiries, and responses.   7. Middleware   The component will be primarily responsible for integrating the different systems components under a common platform. It should provide a Standards-Based Platform for building Service Oriented Architecture and Composite Applications. The following lists the high-level roles and responsibilities executed by the Middleware component in the end-to-end solution.   ·       As an integration framework, covering to and fro interfaces ·       Provide a web service framework with service registry. ·       Support SOA framework with SOA service registry. ·       Each of the interfaces from / to Middleware to other components would handle data transformation, translation, and mapping of data points. ·       Receive data from the caller / activate and/or forward the data to the recipient system in XML format. ·       Use standard XML for data exchange. ·       Provide the response back to the service/call initiator. ·       Provide a tracking until the response completion. ·       Keep a store transitional data against each call/transaction. ·       Interface through Middleware to get any information that is possible and allowed from the existing systems to enterprise systems; e.g., customer profile and customer history, etc. ·       Provide the data in a common unified format to the SOA calls across systems, and follow the Enterprise Architecture directive. ·       Provide an audit trail for all transactions being handled by the component.   8. Network Elements   The term Network Element means a facility or equipment used in the provision of a telecommunications service. Such terms also includes features, functions, and capabilities that are provided by means of such facility or equipment, including subscriber numbers, databases, signaling systems, and information sufficient for billing and collection or used in the transmission, routing, or other provision of a telecommunications service.   Typical network elements in a GSM network are Home Location Register (HLR), Intelligent Network (IN), Mobile Switching Center (MSC), SMS Center (SMSC), and network elements for other value added services like Push-to-talk (PTT), Ring Back Tone (RBT), etc.   Network elements are invoked when subscribers use their telecom devices for any kind of usage. These elements generate usage data and pass it on to downstream systems like mediation and billing system for rating and billing. They also integrate with provisioning systems for order/service fulfillment.   9. 3rd Party Applications   3rd Party systems are applications like content providers, payment gateways, point of sale terminals, and databases/applications maintained by the Government.   Depending on applicability and the type of functionality provided by 3rd party applications, the integration with different telecom systems like CRM, provisioning, and billing will be done.   10. Service Delivery Platform   A service delivery platform (SDP) provides the architecture for the rapid deployment, provisioning, execution, management, and billing of value added telecom services. SDPs are based on the concept of SOA and layered architecture. They support the delivery of voice, data services, and content in network and device-independent fashion. They allow application developers to aggregate network capabilities, services, and sources of content. SDPs typically contain layers for web services exposure, service application development, and network abstraction.   SOA Reference Architecture   SOA concept is based on the principle of developing reusable business service and building applications by composing those services, instead of building monolithic applications in silos. It’s about bridging the gap between business and IT through a set of business-aligned IT services, using a set of design principles, patterns, and techniques.   In an SOA, resources are made available to participants in a value net, enterprise, line of business (typically spanning multiple applications within an enterprise or across multiple enterprises). It consists of a set of business-aligned IT services that collectively fulfill an organization’s business processes and goals. We can choreograph these services into composite applications and invoke them through standard protocols. SOA, apart from agility and reusability, enables:   ·       The business to specify processes as orchestrations of reusable services ·       Technology agnostic business design, with technology hidden behind service interface ·       A contractual-like interaction between business and IT, based on service SLAs ·       Accountability and governance, better aligned to business services ·       Applications interconnections untangling by allowing access only through service interfaces, reducing the daunting side effects of change ·       Reduced pressure to replace legacy and extended lifetime for legacy applications, through encapsulation in services   ·       A Cloud Computing paradigm, using web services technologies, that makes possible service outsourcing on an on-demand, utility-like, pay-per-usage basis   The following section represents the Reference Architecture of logical view for the Telecom Solution. The new custom built application needs to align with this logical architecture in the long run to achieve EA benefits.   Packaged implementation applications, such as ERP billing applications, need to expose their functions as service providers (as other applications consume) and interact with other applications as service consumers.   COT applications need to expose services through wrappers such as adapters to utilize existing resources and at the same time achieve Enterprise Architecture goal and objectives.   The following are the various layers for Enterprise level deployment of SOA. This diagram captures the abstract view of Enterprise SOA layers and important components of each layer. Layered architecture means decomposition of services such that most interactions occur between adjacent layers. However, there is no strict rule that top layers should not directly communicate with bottom layers.   The diagram below represents the important logical pieces that would result from overall SOA transformation. @font-face { font-family: "Arial"; }@font-face { font-family: "Courier New"; }@font-face { font-family: "Wingdings"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoCaption, li.MsoCaption, div.MsoCaption { margin: 0cm 0cm 10pt; font-size: 9pt; font-family: "Times New Roman"; color: rgb(79, 129, 189); font-weight: bold; }p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpFirst, li.MsoListParagraphCxSpFirst, div.MsoListParagraphCxSpFirst { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpMiddle, li.MsoListParagraphCxSpMiddle, div.MsoListParagraphCxSpMiddle { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }p.MsoListParagraphCxSpLast, li.MsoListParagraphCxSpLast, div.MsoListParagraphCxSpLast { margin: 0cm 0cm 0.0001pt 36pt; font-size: 12pt; font-family: "Times New Roman"; }div.Section1 { page: Section1; }ol { margin-bottom: 0cm; }ul { margin-bottom: 0cm; } Figure 3. Enterprise SOA Reference Architecture 1.          Operational System Layer: This layer consists of all packaged applications like CRM, ERP, custom built applications, COTS based applications like Billing, Revenue Management, Fulfilment, and the Enterprise databases that are essential and contribute directly or indirectly to the Enterprise OSS/BSS Transformation.   ERP holds the data of Asset Lifecycle Management, Supply Chain, and Advanced Procurement and Human Capital Management, etc.   CRM holds the data related to Order, Sales, and Marketing, Customer Care, Partner Relationship Management, Loyalty, etc.   Content Management handles Enterprise Search and Query. Billing application consists of the following components:   ·       Collections Management, Customer Billing Management, Invoices, Real-Time Rating, Discounting, and Applying of Charges ·       Enterprise databases will hold both the application and service data, whether structured or unstructured.   MDM - Master data majorly consists of Customer, Order, Product, and Service Data.     2.          Enterprise Component Layer:   This layer consists of the Application Services and Common Services that are responsible for realizing the functionality and maintaining the QoS of the exposed services. This layer uses container-based technologies such as application servers to implement the components, workload management, high availability, and load balancing.   Application Services: This Service Layer enables application, technology, and database abstraction so that the complex accessing logic is hidden from the other service layers. This is a basic service layer, which exposes application functionalities and data as reusable services. The three types of the Application access services are:   ·       Application Access Service: This Service Layer exposes application level functionalities as a reusable service between BSS to BSS and BSS to OSS integration. This layer is enabled using disparate technology such as Web Service, Integration Servers, and Adaptors, etc.   ·       Data Access Service: This Service Layer exposes application data services as a reusable reference data service. This is done via direct interaction with application data. and provides the federated query.   ·       Network Access Service: This Service Layer exposes provisioning layer as a reusable service from OSS to OSS integration. This integration service emphasizes the need for high performance, stateless process flows, and distributed design.   Common Services encompasses management of structured, semi-structured, and unstructured data such as information services, portal services, interaction services, infrastructure services, and security services, etc.   3.          Integration Layer:   This consists of service infrastructure components like service bus, service gateway for partner integration, service registry, service repository, and BPEL processor. Service bus will carry the service invocation payloads/messages between consumers and providers. The other important functions expected from it are itinerary based routing, distributed caching of routing information, transformations, and all qualities of service for messaging-like reliability, scalability, and availability, etc. Service registry will hold all contracts (wsdl) of services, and it helps developers to locate or discover service during design time or runtime.   • BPEL processor would be useful in orchestrating the services to compose a complex business scenario or process. • Workflow and business rules management are also required to support manual triggering of certain activities within business process. based on the rules setup and also the state machine information. Application, data, and service mediation layer typically forms the overall composite application development framework or SOA Framework.   4.          Business Process Layer: These are typically the intermediate services layer and represent Shared Business Process Services. At Enterprise Level, these services are from Customer Management, Order Management, Billing, Finance, and Asset Management application domains.   5.          Access Layer: This layer consists of portals for Enterprise and provides a single view of Enterprise information management and dashboard services.   6.          Channel Layer: This consists of various devices; applications that form part of extended enterprise; browsers through which users access the applications.   7.          Client Layer: This designates the different types of users accessing the enterprise applications. The type of user typically would be an important factor in determining the level of access to applications.   8.          Vertical pieces like management, monitoring, security, and development cut across all horizontal layers Management and monitoring involves all aspects of SOA-like services, SLAs, and other QoS lifecycle processes for both applications and services surrounding SOA governance.     9.          EA Governance, Reference Architecture, Roadmap, Principles, and Best Practices:   EA Governance is important in terms of providing the overall direction to SOA implementation within the enterprise. This involves board-level involvement, in addition to business and IT executives. At a high level, this involves managing the SOA projects implementation, managing SOA infrastructure, and controlling the entire effort through all fine-tuned IT processes in accordance with COBIT (Control Objectives for Information Technology).   Devising tools and techniques to promote reuse culture, and the SOA way of doing things needs competency centers to be established in addition to training the workforce to take up new roles that are suited to SOA journey.   Conclusions   Reference Architectures can serve as the basis for disparate architecture efforts throughout the organization, even if they use different tools and technologies. Reference architectures provide best practices and approaches in the independent way a vendor deals with technology and standards. Reference Architectures model the abstract architectural elements for an enterprise independent of the technologies, protocols, and products that are used to implement an SOA. Telecom enterprises today are facing significant business and technology challenges due to growing competition, a multitude of services, and convergence. Adopting architectural best practices could go a long way in meeting these challenges. The use of SOA-based architecture for communication to each of the external systems like Billing, CRM, etc., in OSS/BSS system has made the architecture very loosely coupled, with greater flexibility. Any change in the external systems would be absorbed at the Integration Layer without affecting the rest of the ecosystem. The use of a Business Process Management (BPM) tool makes the management and maintenance of the business processes easy, with better performance in terms of lead time, quality, and cost. Since the Architecture is based on standards, it will lower the cost of deploying and managing OSS/BSS applications over their lifecycles.

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  • Silverlight 4 Training Kit

    - by ScottGu
    We recently released a new free Silverlight 4 Training Kit that walks you through building business applications with Silverlight 4.  You can browse the training kit online or alternatively download an entire offline version of the training kit.  The training material is structured on teaching how to use the new Silverlight 4 features to build an end to end business application. The training kit includes 8 modules, 25 videos, and several hands on labs. Below is a breakdown and links to all of the content. [In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu] Module 1: Introduction Click here to watch this module. In this video John Papa and Ian Griffiths discuss the key areas that the Building Business Applications with Silverlight 4 course focuses on. This module is the overview of the course and covers many key scenarios that are faced when building business applications, and how Silverlight can help address them. Module 2: WCF RIA Services Click here to explore this module. In this lab, you will create a web site for managing conferences that will be the basis for the other labs in this course. Don’t worry if you don’t complete a particular lab in the series – all lab manual instructions are accompanied by completed solutions, so you can either build your own solution from start to finish, or dive straight in at any point using the solutions provided as a starting point. In this lab you will learn how to set up WCF RIA Services, create bindings to the domain context, filter using the domain data source, and create domain service queries. Online Link Download Source Download Lab Document Videos Module 2.1 - WCF RIA Services Ian Griffiths sets up the Entity Framework and WCF RIA Services for the sample Event Manager application for the course. He covers how to set up the services, how the Domain Services work and the role that the DomainContext plays in the sample application. He also reviews the metadata classes and integrating the navigation framework. Module 2.2 – Using WCF RIA Services to Edit Entities Ian Griffiths discusses how he adds the ability to edit and create individual entities with the features built into WCF RIA Services into the sample Event Manager application. He covers data binding fundamentals, IQueryable, LINQ, the DomainDataSource, navigation to a single entity using the navigation framework, and how to use the Visual Studio designer to do much of the work . Module 2.3 – Showing Master/Details Records Using WCF RIA Services Ian Griffiths reviews how to display master/detail records for the sample Event Manager application using WCF RIA Services. He covers how to use the Include attribute to indicate which elements to serialize back to the client. Ian also demonstrates how to use the Data Sources window in the designer to add and bind controls to specific data elements. He wraps up by showing how to create custom services to the Domain Services. Module 3 – Authentication, Validation, MVVM, Commands, Implicit Styles and RichTextBox Click here to visit this module. This lab demonstrates how to build a login screen, integrate ASP.NET authentication, and perform validation on data elements. Model-View-ViewModel (MVVM) is introduced and used in this lab as a pattern to help separate the UI and business logic. You will also learn how to use implicit styling and the new RichTextBox control. Online Link Download Source Download Lab Document Videos Module 3.1 – Authentication Ian Griffiths covers how to integrate a login screen and authentication into the sample Event Manager application. Ian shows how to use the ASP.NET authentication and integrate it into WCF RIA Services and the Silverlight presentation layer. Module 3.2 – MVVM Ian Griffiths covers how to Model-View-ViewModel (MVVM) patterns into the sample Event Manager application. He discusses why MVVM exists, what separated presentation means, and why it is important. He shows how to connect the View to the ViewModel, why data binding is important in this symbiosis, and how everything fits together in the overall application. Module 3.3 –Validation Ian Griffiths discusses how validation of user input can be integrated into the sample Event Manager application. He demonstrates how to use the DataAnnotations, the INotifyDataErrorInfo interface, binding markup extensions, and WCF RIA Services in concert to achieve great validation in the sample application. He discusses how this technique allows for property level validation, entity level validation, and asynchronous server side validation. Module 3.4 – Implicit Styles Ian Griffiths discusses how why implicit styles are important and how they can be integrated into the sample Event Manager application. He shows how implicit styles defined in a resource dictionary can be applied to all elements of a particular kind throughout the application. Module 3.5 – RichTextBox Ian Griffiths discusses how the new RichTextBox control and it can be integrated into the sample Event Manager application. He demonstrates how the RichTextBox can provide editing for the event information and how it can display the rich text for selection and copying. Module 4 – User Profiles, Drop Targets, Webcam and Clipboard Click here to visit this module. This lab builds new features into the sample application to take the user's photo. It teaches you how to use the webcam to capture an image, use Silverlight as a drop target, and take advantage of programmatic access to the clipboard. Link Download Source Download Lab Document Videos Module 4.1 – Webcam Ian Griffiths demonstrates how the webcam adds value to the sample Event Manager application by capturing an image of the attendee. He discusses the VideoCaptureDevice, the CaptureDviceConfiguration, and the CaptureSource classes and how they allow audio and video to be captured so you can grab an image from the capture device and save it. Module 4.2 - Drag and Drop in Silverlight Ian Griffiths demonstrates how to capture and handle the Drop in the sample Event Manager application so the user can drag a photo from a file and drop it into the application. Ian reviews the AllowDrop property, the Drop event, how to access the file that can be dropped, and the other drag related events. He also reviews how to make this work across browsers and the challenges for this. Module 5 – Schedule Planner and Right Mouse Click Click here to visit this module. This lab builds on the application to allow grouping in the DataGrid and implement right mouse click features to add context menu support. Link Download Source Download Lab Document Videos Module 5.1 – Grouping and Binding Ian Griffiths demonstrates how to use the grouping features for data binding in the DataGrid and how it applies to the sample Event Manager application. He reviews the role of the CollectionViewSource in grouping, customizing the templates for headers, and how to work with grouping with ItemsControls. Module 5.2 – Layout Visual States Ian Griffiths demonstrates how to use the Fluid UI animation support for visual states in the ListBox control DataGrid and how it applies to the sample Event Manager application. He reviews the 3 visual states of BeforeLoaded, AfterLoaded, and BeforeUnloaded. Module 5.3 – Right Mouse Click Ian Griffiths demonstrates how to add support for handling the right mouse button click event to display a context menu for the Event Manager application. He demonstrates how to handle the event, show a custom context menu control, and integrate it into the scheduling portion of the application. Module 6 – Printing the Schedule Click here to visit this module. This lab teaches how to use the new printing features in Silverlight 4. The lab walks through the PrintDocument class and the ViewBox control, while showing how to print multiple pages of content using them. Link Download Source Download Lab Document Videos Module 6.1 – Printing and the Viewbox Ian Griffiths demonstrates how to add the ability to print the schedule to the sample Event Manager application. He walks through the importance of the PrintDocument class and its members. He also shows how to handle printing the visual tree and how the ViewBox control can help. Module 6.2 – Multi Page Printing Ian Griffiths expands on his printing discussion by showing how to handle printing multiple pages of content for the sample Event Manager application. He shows how to paginate the content and points out various tips to keep in mind when determining the printable area. Module 7 – Running the Event Dashboard Out of Browser Click here to visit this module. This lab builds a dashboard for the sample application while explaining the fundamentals of the out of browser features, how to handle authentication, displaying notifications (toasts), and how to use native integration to use COM Interop with Silverlight. Link Download Source Download Lab Document Videos Module 7.1 – Out of Browser Ian Griffiths discusses the role of an Out of Browser application for administrators to manage the events and users in the sample Event Manager application. He discusses several reasons why out of browser applications may better suit your needs including custom chrome, toasts, window placement, cross domain access, and file access. He demonstrates the basic technique to take your application and make it work out of browser using the tools. Module 7.2 – NotificationWindow (Toasts) for Elevated Trust Out of Browser Applications Ian Griffiths discusses the how toasts can be used in the sample Event Manager application to show information that may require the user's attention. Ian covers how to create a toast using the NotificationWindow, security implications, and how to make the toast appear as needed. Module 7.3 – Out of Browser Window Placement Ian Griffiths discusses the how to manage the window positioning when building an out of browser application, handling the windows state, and controlling and handling activation of the window. Module 7.4 – Out of Browser Elevated Trust Application Overview Ian Griffiths discusses the implications of creating trusted out of browser application for the Event Manager sample application. He reviews why you might want to use elevated trust, what features is opens to you, and how to take advantage of them. Topics Ian covers include the dynamic keyword in C# 4, the AutomationFactory class, the API to check if you are in a trusted application, and communicating with Excel. Module 8 – Advanced Out of Browser and MEF Click here to visit this module. This hands-on lab walks through the creation of a trusted out of browser application and the new functionality that comes with that. You will learn to use COM Automation, handle the window closing event, set custom window chrome, digitally sign your Silverlight out of browser trusted application, create a silent install option, and take advantage of MEF. Link Download Source Download Lab Document Videos Module 8.1 – Custom Window Chrome for Elevated Trust Out of Browser Applications Ian Griffiths discusses how to replace the standard operating system window chrome with customized chrome for an elevated trusted out of browser application. He covers how it is important to handle close, resize, minimize, and maximize events. Ian mentions that the tooling was not ready when he shot this video, but the good news is that the tooling now supports setting the custom chrome directly from the property page for the Silverlight application. Module 8.2 – Window Closing Event for Out of Browser Applications Ian Griffiths discusses the WindowClosing event and how to handle and optionally cancel the event. Module 8.3 – Silent Install of Out of Browser Applications Ian Griffiths discusses how to use the SLLauncher executable to install an out of browser application. He discusses the optional command line switches that can be set including how the emulate switch can help you emulate the install process. Ian also shows how to setup a shortcut for the application and tell the application where it should look for future updates online. Module 8.4 – Digitally Signing Out of Browser Application Ian Griffiths discusses how and why to digitally sign an out of browser application using the signtool program. He covers what trusted certificates are, the implications of signing (or not signing), and the effect on the user experience. Module 8.5 – The Value of MEF with Silverlight Ian Griffiths discusses what MEF is, how your application can benefit from it, and the fundamental features it puts at your disposal. He covers the 3 step import, export and compose process as well as how to dynamically import XAP files using MEF. Summary As you can probably tell from the long list above – this series contains a ton of great content, and hopefully provides a nice end-to-end walkthrough that helps explain how to take advantage of Silverlight 4 (and all its new features).  Hope this helps, Scott

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  • GuestPost: Unit Testing Entity Framework (v1) Dependent Code using TypeMock Isolator

    - by Eric Nelson
    Time for another guest post (check out others in the series), this time bringing together the world of mocking with the world of Entity Framework. A big thanks to Moses for agreeing to do this. Unit Testing Entity Framework Dependent Code using TypeMock Isolator by Muhammad Mosa Introduction Unit testing data access code in my opinion is a challenging thing. Let us consider unit tests and integration tests. In integration tests you are allowed to have environmental dependencies such as a physical database connection to insert, update, delete or retrieve your data. However when performing unit tests it is often much more efficient and productive to remove environmental dependencies. Instead you will need to fake these dependencies. Faking a database (also known as mocking) can be relatively straight forward but the version of Entity Framework released with .Net 3.5 SP1 has a number of implementation specifics which actually makes faking the existence of a database quite difficult. Faking Entity Framework As mentioned earlier, to effectively unit test you will need to fake/simulate Entity Framework calls to the database. There are many free open source mocking frameworks that can help you achieve this but it will require additional effort to overcome & workaround a number of limitations in those frameworks. Examples of these limitations include: Not able to fake calls to non virtual methods Not able to fake sealed classes Not able to fake LINQ to Entities queries (replace database calls with in-memory collection calls) There is a mocking framework which is flexible enough to handle limitations such as those above. The commercially available TypeMock Isolator can do the job for you with less code and ultimately more readable unit tests. I’m going to demonstrate tackling one of those limitations using MoQ as my mocking framework. Then I will tackle the same issue using TypeMock Isolator. Mocking Entity Framework with MoQ One basic need when faking Entity Framework is to fake the ObjectContext. This cannot be done by passing any connection string. You have to pass a correct Entity Framework connection string that specifies CSDL, SSDL and MSL locations along with a provider connection string. Assuming we are going to do that, we’ll explore another limitation. The limitation we are going to face now is related to not being able to fake calls to non-virtual/overridable members with MoQ. I have the following repository method that adds an EntityObject (instance of a Blog entity) to Blogs entity set in an ObjectContext. public override void Add(Blog blog) { if(BlogContext.Blogs.Any(b=>b.Name == blog.Name)) { throw new InvalidOperationException("Blog with same name already exists!"); } BlogContext.AddToBlogs(blog); } The method does a very simple check that the name of the new Blog entity instance doesn’t exist. This is done through the simple LINQ query above. If the blog doesn’t already exist it simply adds it to the current context to be saved when SaveChanges of the ObjectContext instance (e.g. BlogContext) is called. However, if a blog with the same name exits, and exception (InvalideOperationException) will be thrown. Let us now create a unit test for the Add method using MoQ. [TestMethod] [ExpectedException(typeof(InvalidOperationException))] public void Add_Should_Throw_InvalidOperationException_When_Blog_With_Same_Name_Already_Exits() { //(1) We shouldn't depend on configuration when doing unit tests! But, //its a workaround to fake the ObjectContext string connectionString = ConfigurationManager .ConnectionStrings["MyBlogConnString"] .ConnectionString; //(2) Arrange: Fake ObjectContext var fakeContext = new Mock<MyBlogContext>(connectionString); //(3) Next Line will pass, as ObjectContext now can be faked with proper connection string var repo = new BlogRepository(fakeContext.Object); //(4) Create fake ObjectQuery<Blog>. Will be used to substitute MyBlogContext.Blogs property var fakeObjectQuery = new Mock<ObjectQuery<Blog>>("[Blogs]", fakeContext.Object); //(5) Arrange: Set Expectations //Next line will throw an exception by MoQ: //System.ArgumentException: Invalid setup on a non-overridable member fakeContext.SetupGet(c=>c.Blogs).Returns(fakeObjectQuery.Object); fakeObjectQuery.Setup(q => q.Any(b => b.Name == "NewBlog")).Returns(true); //Act repo.Add(new Blog { Name = "NewBlog" }); } This test method is checking to see if the correct exception ([ExpectedException(typeof(InvalidOperationException))]) is thrown when a developer attempts to Add a blog with a name that’s already exists. On (1) a connection string is initialized from configuration file. To retrieve the full connection string. On (2) a fake ObjectContext is being created. The ObjectContext here is MyBlogContext and its being created using this var fakeContext = new Mock<MyBlogContext>(connectionString); This way a fake context is being created using MoQ. On (3) a BlogRepository instance is created. BlogRepository has dependency on generate Entity Framework ObjectContext, MyObjectContext. And so the fake context is passed to the constructor. var repo = new BlogRepository(fakeContext.Object); On (4) a fake instance of ObjectQuery<Blog> is being created to use as a substitute to MyObjectContext.Blogs property as we will see in (5). On (5) setup an expectation for calling Blogs property of MyBlogContext and substitute the return result with the fake ObjectQuery<Blog> instance created on (4). When you run this test it will fail with MoQ throwing an exception because of this line: fakeContext.SetupGet(c=>c.Blogs).Returns(fakeObjectQuery.Object); This happens because the generate property MyBlogContext.Blogs is not virtual/overridable. And assuming it is virtual or you managed to make it virtual it will fail at the following line throwing the same exception: fakeObjectQuery.Setup(q => q.Any(b => b.Name == "NewBlog")).Returns(true); This time the test will fail because the Any extension method is not virtual/overridable. You won’t be able to replace ObjectQuery<Blog> with fake in memory collection to test your LINQ to Entities queries. Now lets see how replacing MoQ with TypeMock Isolator can help. Mocking Entity Framework with TypeMock Isolator The following is the same test method we had above for MoQ but this time implemented using TypeMock Isolator: [TestMethod] [ExpectedException(typeof(InvalidOperationException))] public void Add_New_Blog_That_Already_Exists_Should_Throw_InvalidOperationException() { //(1) Create fake in memory collection of blogs var fakeInMemoryBlogs = new List<Blog> {new Blog {Name = "FakeBlog"}}; //(2) create fake context var fakeContext = Isolate.Fake.Instance<MyBlogContext>(); //(3) Setup expected call to MyBlogContext.Blogs property through the fake context Isolate.WhenCalled(() => fakeContext.Blogs) .WillReturnCollectionValuesOf(fakeInMemoryBlogs.AsQueryable()); //(4) Create new blog with a name that already exits in the fake in memory collection in (1) var blog = new Blog {Name = "FakeBlog"}; //(5) Instantiate instance of BlogRepository (Class under test) var repo = new BlogRepository(fakeContext); //(6) Acting by adding the newly created blog () repo.Add(blog); } When running the above test method it will pass as the Add method of BlogRepository is going to throw an InvalidOperationException which is the expected behaviour. Nothing prevents us from faking out the database interaction! Even faking ObjectContext  at (2) didn’t require a connection string. On (3) Isolator sets up a faking result for MyBlogContext.Blogs when its being called through the fake instance fakeContext created on (2). The faking result is just an in-memory collection declared an initialized on (1). Finally at (6) action we call the Add method of BlogRepository passing a new Blog instance that has a name that’s already exists in the fake in-memory collection which we set up at (1). As expected the test will pass because it will throw the expected exception defined on top of the test method - InvalidOperationException. TypeMock Isolator succeeded in faking Entity Framework with ease. Conclusion We explored how to write a simple unit test using TypeMock Isolator for code which is using Entity Framework. We also explored a few of the limitations of other mocking frameworks which TypeMock is successfully able to handle. There are workarounds that you can use to overcome limitations when using MoQ or Rhino Mock, however the workarounds will require you to write more code and your tests will likely be more complex. For a comparison between different mocking frameworks take a look at this document produced by TypeMock. You might also want to check out this open source project to compare mocking frameworks. I hope you enjoyed this post Muhammad Mosa http://mosesofegypt.net/ http://twitter.com/mosessaur Screencast of unit testing Entity Framework Related Links GuestPost: Introduction to Mocking GuesPost: Typemock Isolator – Much more than an Isolation framework

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  • 30 seconds from File|New to a new CRUD Silverlight application with Teleriks new LINQ Implementation

    Last month Telerik released its new LINQ implementation and last week we released the new Data Services Wizard for Telerik OpenAccess, which supports both traditional OpenAccess entities and the new LINQ implementation. I will a walk you through the process where you can connect to a database, add a new domain model, wrap it in a new WCF Data Services (Astoria) service, and add a CRUD enabled Silverlight application. All in 30 seconds! Step 1: Build your Domain Model (20 seconds) Open Visual Studio 2010 RTM (or 2008) and add a new ASP.NET project. Right click on the project and select Add|New Item and choose Telerk OpenAccess Domain Model from the item template list. The Visual Entity Designer wizard comes up. Select the database server you are using in the first screen (SQL Server, Oracle, SQL Azure, MySQL, etc) and then also build your database connection string. Next select the tables, views, and stored procedures you want ...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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  • Restful Services, oData, and Rest Sharp

    - by jkrebsbach
    After a great presentation by Jason Sheehan at MDC about RestSharp, I decided to implement it. RestSharp is a .Net framework for consuming restful data sources via either Json or XML. My first step was to put together a Restful data source for RestSharp to consume.  Staying entirely withing .Net, I decided to use Microsoft's oData implementation, built on System.Data.Services.DataServices.  Natively, these support Json, or atom+pub xml.  (XML with a few bells and whistles added on) There are three main steps for creating an oData data source: 1)  override CreateDSPMetaData This is where the metadata data is returned.  The meta data defines the structure of the data to return.  The structure contains the relationships between data objects, along with what properties the objects expose.  The meta data can and should be somehow cached so that the structure is not rebuild with every data request. 2) override CreateDataSource The context contains the data the data source will publish.  This method is the conduit which will populate the metadata objects to be returned to the requestor. 3) implement static InitializeService At this point we can set up security, along with setting up properties of the web service (versioning, etc)   Here is a web service which publishes stock prices for various Products (stocks) in various Categories. namespace RestService {     public class RestServiceImpl : DSPDataService<DSPContext>     {         private static DSPContext _context;         private static DSPMetadata _metadata;         /// <summary>         /// Populate traversable data source         /// </summary>         /// <returns></returns>         protected override DSPContext CreateDataSource()         {             if (_context == null)             {                 _context = new DSPContext();                 Category utilities = new Category(0);                 utilities.Name = "Electric";                 Category financials = new Category(1);                 financials.Name = "Financial";                                 IList products = _context.GetResourceSetEntities("Products");                 Product electric = new Product(0, utilities);                 electric.Name = "ABC Electric";                 electric.Description = "Electric Utility";                 electric.Price = 3.5;                 products.Add(electric);                 Product water = new Product(1, utilities);                 water.Name = "XYZ Water";                 water.Description = "Water Utility";                 water.Price = 2.4;                 products.Add(water);                 Product banks = new Product(2, financials);                 banks.Name = "FatCat Bank";                 banks.Description = "A bank that's almost too big";                 banks.Price = 19.9; // This will never get to the client                 products.Add(banks);                 IList categories = _context.GetResourceSetEntities("Categories");                 categories.Add(utilities);                 categories.Add(financials);                 utilities.Products.Add(electric);                 utilities.Products.Add(electric);                 financials.Products.Add(banks);             }             return _context;         }         /// <summary>         /// Setup rules describing published data structure - relationships between data,         /// key field, other searchable fields, etc.         /// </summary>         /// <returns></returns>         protected override DSPMetadata CreateDSPMetadata()         {             if (_metadata == null)             {                 _metadata = new DSPMetadata("DemoService", "DataServiceProviderDemo");                 // Define entity type product                 ResourceType product = _metadata.AddEntityType(typeof(Product), "Product");                 _metadata.AddKeyProperty(product, "ProductID");                 // Only add properties we wish to share with end users                 _metadata.AddPrimitiveProperty(product, "Name");                 _metadata.AddPrimitiveProperty(product, "Description");                 EntityPropertyMappingAttribute att = new EntityPropertyMappingAttribute("Name",                     SyndicationItemProperty.Title, SyndicationTextContentKind.Plaintext, true);                 product.AddEntityPropertyMappingAttribute(att);                 att = new EntityPropertyMappingAttribute("Description",                     SyndicationItemProperty.Summary, SyndicationTextContentKind.Plaintext, true);                 product.AddEntityPropertyMappingAttribute(att);                 // Define products as a set of product entities                 ResourceSet products = _metadata.AddResourceSet("Products", product);                 // Define entity type category                 ResourceType category = _metadata.AddEntityType(typeof(Category), "Category");                 _metadata.AddKeyProperty(category, "CategoryID");                 _metadata.AddPrimitiveProperty(category, "Name");                 _metadata.AddPrimitiveProperty(category, "Description");                 // Define categories as a set of category entities                 ResourceSet categories = _metadata.AddResourceSet("Categories", category);                 att = new EntityPropertyMappingAttribute("Name",                     SyndicationItemProperty.Title, SyndicationTextContentKind.Plaintext, true);                 category.AddEntityPropertyMappingAttribute(att);                 att = new EntityPropertyMappingAttribute("Description",                     SyndicationItemProperty.Summary, SyndicationTextContentKind.Plaintext, true);                 category.AddEntityPropertyMappingAttribute(att);                 // A product has a category, a category has products                 _metadata.AddResourceReferenceProperty(product, "Category", categories);                 _metadata.AddResourceSetReferenceProperty(category, "Products", products);             }             return _metadata;         }         /// <summary>         /// Based on the requesting user, can set up permissions to Read, Write, etc.         /// </summary>         /// <param name="config"></param>         public static void InitializeService(DataServiceConfiguration config)         {             config.SetEntitySetAccessRule("*", EntitySetRights.All);             config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2;             config.DataServiceBehavior.AcceptProjectionRequests = true;         }     } }     The objects prefixed with DSP come from the samples on the oData site: http://www.odata.org/developers The products and categories objects are POCO business objects with no special modifiers. Three main options are available for defining the MetaData of data sources in .Net: 1) Generate Entity Data model (Potentially directly from SQL Server database).  This requires the least amount of manual interaction, and uses the edmx WYSIWYG editor to generate a data model.  This can be directly tied to the SQL Server database and generated from the database if you want a data access layer tightly coupled with your database. 2) Object model decorations.  If you already have a POCO data layer, you can decorate your objects with properties to statically inform the compiler how the objects are related.  The disadvantage is there are now tags strewn about your business layer that need to be updated as the business rules change.  3) Programmatically construct metadata object.  This is the object illustrated above in CreateDSPMetaData.  This puts all relationship information into one central programmatic location.  Here business rules are constructed when the DSPMetaData response object is returned.   Once you have your service up and running, RestSharp is designed for XML / Json, along with the native Microsoft library.  There are currently some differences between how Jason made RestSharp expect XML with how atom+pub works, so I found better results currently with the Json implementation - modifying the RestSharp XML parser to make an atom+pub parser is fairly trivial though, so use what implementation works best for you. I put together a sample console app which calls the RestSvcImpl.svc service defined above (and assumes it to be running on port 2000).  I used both RestSharp as a client, and also the default Microsoft oData client tools. namespace RestConsole {     class Program     {         private static DataServiceContext _ctx;         private enum DemoType         {             Xml,             Json         }         static void Main(string[] args)         {             // Microsoft implementation             _ctx = new DataServiceContext(new System.Uri("http://localhost:2000/RestServiceImpl.svc"));             var msProducts = RunQuery<Product>("Products").ToList();             var msCategory = RunQuery<Category>("/Products(0)/Category").AsEnumerable().Single();             var msFilteredProducts = RunQuery<Product>("/Products?$filter=length(Name) ge 4").ToList();             // RestSharp implementation                          DemoType demoType = DemoType.Json;             var client = new RestClient("http://localhost:2000/RestServiceImpl.svc");             client.ClearHandlers(); // Remove all available handlers             // Set up handler depending on what situation dictates             if (demoType == DemoType.Json)                 client.AddHandler("application/json", new RestSharp.Deserializers.JsonDeserializer());             else if (demoType == DemoType.Xml)             {                 client.AddHandler("application/atom+xml", new RestSharp.Deserializers.XmlDeserializer());             }                          var request = new RestRequest();             if (demoType == DemoType.Json)                 request.RootElement = "d"; // service root element for json             else if (demoType == DemoType.Xml)             {                 request.XmlNamespace = "http://www.w3.org/2005/Atom";             }                              // Return all products             request.Resource = "/Products?$orderby=Name";             RestResponse<List<Product>> productsResp = client.Execute<List<Product>>(request);             List<Product> products = productsResp.Data;             // Find category for product with ProductID = 1             request.Resource = string.Format("/Products(1)/Category");             RestResponse<Category> categoryResp = client.Execute<Category>(request);             Category category = categoryResp.Data;             // Specialized queries             request.Resource = string.Format("/Products?$filter=ProductID eq {0}", 1);             RestResponse<Product> productResp = client.Execute<Product>(request);             Product product = productResp.Data;                          request.Resource = string.Format("/Products?$filter=Name eq '{0}'", "XYZ Water");             productResp = client.Execute<Product>(request);             product = productResp.Data;         }         private static IEnumerable<TElement> RunQuery<TElement>(string queryUri)         {             try             {                 return _ctx.Execute<TElement>(new Uri(queryUri, UriKind.Relative));             }             catch (Exception ex)             {                 throw ex;             }         }              } }   Feel free to step through the code a few times and to attach a debugger to the service as well to see how and where the context and metadata objects are constructed and returned.  Pay special attention to the response object being returned by the oData service - There are several properties of the RestRequest that can be used to help troubleshoot when the structure of the response is not exactly what would be expected.

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  • CodePlex Daily Summary for Wednesday, May 05, 2010

    CodePlex Daily Summary for Wednesday, May 05, 2010New Projects2010微软精英大挑战Heritage of Dragon项目: 我们来自上海市同济大学,兴趣相投,集聚于此共同构建一个开放的网络平台。致力于运用构建在云端基于地图的服务,使用文字、图片、视频、互动动画等形式来展示全国各地的传统手工艺。并且充分发挥网络的优势,通过开放协作的维基平台人人都可以参与到内容的添加修改与完善中来。目的在于记录、展示、挖掘、传承中国古...AutoArchive: Auto archive your "my documents" to a remote machine. I'm writing this so my wife can put things in "my documents" and it'll automaticly archive i...BigDoor .NET Client: A .NET client for the BigDoor Media API. The API enables secured virtual transactions with support for any number of currencies, transactions, awar...bubujie: Dreamweaver LibraryGeckoGit: GeckoGit is a combination of TortoiseSVN and AnkhSVN, but for Git repositories, and built on the GitSharp library.Global: global, config, mail, http, rest, xml, serialization, helper, path, ioIndustrial Dashboard Connected Grid webpart: This Sharepoint 2007/10 webpart provides a simple way to display grid based reports populated with data that comes from a SQL Server stored procedu...IpControls: "IpControls" contains IPv4 and IPv6 text boxes, both as Windows Forms and WPF version. The IPv6 control automatically detects the older hybrid for...LiteME: LiteME is short for LiteMapleStoryEmulator... it is v75, open-source, and still going through it's alpha stages. It is still in development!Meditel PHP Class: Une classe PHP qui vous permet de d'envoyer des SMS vers tous les numeros Meditel en utilisant leservice des SMS gratuits depuis le site Meditel.maMoneySafe: Help people.Mouse Zoom - Visual Studio Extension: Mouse Zoom is a Visual Studio 2010 extension that will cause the mouse zoom functionality to zoom at the mouse's cursor instead of at the top of th...Multi-Language Words Memorizer: This .net application is designed for learning words and help foreign language learners by lots of automatic features. After you select a list of ...Navigation for ASP.NET Web Forms: Navigation for ASP.NET Web Forms manages movement and data passing between aspx Pages in a unit testable manner. There is no Client-side logic, so ...NazTek.Extension.Clr4: CLR 4.0 extensions and utility APIOpalis Community Releases: Sample workflows, objects, code and other items related to System Center's Opalis Integration Server, published by the Opalis team.Power Video Player: Power Video Player is a slim feature-rich video/dvd player that meets everyday needs in video playback on PC with a bunch of advanced features on b...SchemeEditor: <WPF> <.NET> <Editor> <Silverlight> <Scheme> <Graphics> <simulink> <schematic>StyleCop+: StyleCop+ is a plug-in that extends original StyleCop features.timemanager2010: Just another work time managerTweetTunes: Updates Twitter with current song playing in iTunes - if your Twitter account is linked to Facebook - it will update that too The twittervb2 down...WCF Discovery Library: WCF Discovery Library is a small collection of utilities that makes it easy to add WCF 4.0 Discovery features into your projects.New ReleasesAjaxControlToolkit additional extenders: ControlToolkitExtended: this build contains web example with BreadCrumbsAnyCAD: AnyCAD Free Beta1: AnyCAD Free Beta1Baccarat: Single player practice baccarat: This is a simple baccarat game for Windows Mobile. It is single player and is only a practice version, which will help users familiarize themselve...BigDoor .NET Client: BigDoor .NET 2.0 Client (Alpha): Our first iteration of the .NET client. Please fork and or ask to be added if you want to make any contributions.CBM-Command: 2010-05-04: Release NotesNew Features Panel navigation now complete. Scroll up and down through directories using the up and down cursor keys. Switch between...Directory Linker: Directory Linker 2.1: This release introduces XP support, more information about all features can be found at http://www.humblecoder.co.uk/?p=141Extend SmallBasic: Teaching Extensions v.015: added high low quizGoogle AJAX Search Services for jQuery: jquery.gss-0.1.3.js: First official release - use at your own discretion. Thanks, AndrewIndustrial Dashboard Connected Grid webpart: Filtered Industrial Grid: Filtered Industrial Grid web part for SharePoint 2007/2010, First Release.jQuery Library for SharePoint Web Services: SPServices 0.5.5: IMPORTANT NOTE: This release is in an alpha state. You should only download it if you know what you are getting and are interested in testing it f...Meditel PHP Class: Meditel PHP Class: Zipped File : Example : exemplemeditel.php PHP Class : meditel.class.phpMulti-Language Words Memorizer: Memorizer 1.0: First release.mwNSPECT: mwNSPECT Plugin DLL: mwNSPECT Mapwindow plugin dll. Place in your MapWindow or BASINS plugins directory. Presently only for testing form functionality (not including...mwNSPECT: mwNSPECT Simple Installer: Simplistic mwNSPECT Mapwindow plugin installer using Inno setup. Installs all the files you'll need for NSPECT into the C:\NSPECT folder and insta...MyWSAT - ASP.NET Membership Administration Tool: MyWSAT v3.5.3: MyWSAT 3.5.3 Update Notes - May 4th 2010 1.) Added the user search box and a-z navigation menu to all relevant user gridviews. 2.) Added a membersh...Object/Relational Mapper & Code Generator in Net 2.0 for Relational & XML Schema: 2.7: Upgraded UI-generation templates for special case of associative tables (2-column primary keys). Minor bugfix with template-editor.Open NFSe: Open NFSe 2.0: Versao para Belo Horizonte utilizando Windows Services.Power Video Player: PVP 1.1.3776: v1.1.3776 This is mainly a rebuild of version 1.1 under Ms-PL license and is the 1st version available at CodePlex.PROGRAMMABLE SOFTWARE DEVELOPMENT ENVIRONMENT: PROGRAMMABLE SOFTWARE DEVELOPMENT ENVIRONMENT-3.1: The following error has been corrected: PCG ERROR: srcproj -- 3933 PCG ERROR: srcproj -- 2943 PCG ERROR: devproj -- 1474 PCG ERROR: mainprj -- 128...Rehost Image: 1.3.9: Fixed locations saving for mac and linux platforms.Robot Shootans: Robot Shootans 0.5.1 (Windows): This is the first public release of this game. Instructions on how to play are included in the game itself Known issues: Changing control style wh...SchemeEditor: SchemeEditor Beta: First release. Wait for documentation & update for some new functionSharePoint Rsync List: SharePoint Rsync 0.9.0.0: Initial release of sprsync. Comments, questions, feedback, and code enhancements are welcome!Software Is Hardwork: Sw. Is Hw. Lib. 3.0.0.x+01: Sw. Is Hw. Lib. 3.0.0.x+01 UNSUPPORTED, UNTESTED ALPHA RELEASE Code may disappear. This is just a preview of code that was in progress. Code is s...Software Localization Tool: SharpSLT 1.0.1: Minor release: bug fixes slight changes in the UIStyleCop+: StyleCop+ 0.6: Several important improvements made for Advanced Naming Rules: - Added new entities for fields and constants - Added new entities for methods (incl...turing machine simulator: First version of turing machine: Overview: First version of turing simulator with example script (transaction function). Files: SimulatorGui.exe - main GUI of simulator TuringMach...VCC: Latest build, v2.1.30504.0: Automatic drop of latest buildVocabulary Training Center: Basic Edition 1.1: A release with medium large changes: New functionality: Multiple-choice questions added Grammatical questions added Evaluation changed accordin...Web Service Software Factory: Web Service Software Factory 2010 RC: To use the Web Service Software Factory 2010, you need the following software installed on your computer: • Microsoft Visual Studio 2010 (Ultima...Web Service Software Factory: WSSF2010 Guide: This is the help and guidance for Web Service Software Factory 2010Windows Phone 7 Panorama control: panorama control v0.6 + samples: IMPORTANT NOTE: Please read the following bug + suggested workaround. I'll fix this in a new release shortly. Panorama Control source code + sampl...WPF Behavior Library: WPF Behavior Library 0.2 Release: Drag & Drop Took away the ItemType and DataTemplate requirements Added functions for inheritors to be able to provide custom logic to handle movi...Most Popular ProjectsRawrWBFS ManagerAJAX Control ToolkitMicrosoft SQL Server Product Samples: DatabaseSilverlight Toolkitpatterns & practices – Enterprise LibraryWindows Presentation Foundation (WPF)iTuner - The iTunes CompanionDotNetNuke® Community EditionASP.NETMost Active Projectspatterns & practices – Enterprise LibraryAJAX Control FrameworkHydroServer - CUAHSI Hydrologic Information System ServerIonics Isapi Rewrite Filterpatterns & practices: Azure Security GuidanceRawrBlogEngine.NETTinyProjectNB_Store - Free DotNetNuke Ecommerce Catalog ModuleAll-In-One Code Framework

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  • Silverlight Cream for May 30, 2010 -- #873

    - by Dave Campbell
    In this Issue: Matthias Shapiro, Colin Blair(-2-), Mike Snow, Marlon Grech, Victor Gaudioso. Shoutout: If you're going to be anywhere near Mission Viejo, California on June 19th, set your calendar for this Victor Gaudioso event: New Speaking Event: Microsoft Book Signing/Silverlight 4 Presentation SilverLaw has another example of his Flexible surface app up: Drag & Drop Flexible Surface - Silverlight 4 From SilverlightCream.com: Silverlight 4 Binding and StringFormat in XAML Matthias Shapiro has a discussion posted about StringFormat binding in Silverlight 4 ... he dug in hard on this... well worth a read. View Model Collection Properties for WCF RIA Services Colin Blair is discussing some possibilities for exposing collections of entities from the ViewModel... his favorite: PagedCollectionView. The next post discusses this deeper. Advanced Paged Collection View Colin Blair continues in more depth on the PagedCollectionView, this time handling paging, sorting, and multiple loads. Silverlight Tip of the day #25 – Detecting Validation Errors on Submit Mike Snow's latest Tip of the Day is up and is about validation - specifically validating after your user has pressed "OK" INotifyPropertyChanged… I am fed up of handling events just to know when a property changed Marlon Grech has an Rx-less solution to code notifications of properties changing... this is a WPF and Silverlight solution and all the code is downloadable. New Silverlight Video Tutorial: How to Add Multiple BitmapEffects to One Object Victor Gaudioso's latest outing is in response to a query from a reader and is a video tutorial showing how to add multiple bitmap effects to one object. Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    Windows Phone MIX10

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  • value types in the vm

    - by john.rose
    value types in the vm p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} p.p2 {margin: 0.0px 0.0px 14.0px 0.0px; font: 14.0px Times} p.p3 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times} p.p4 {margin: 0.0px 0.0px 15.0px 0.0px; font: 14.0px Times} p.p5 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier} p.p6 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Courier; min-height: 17.0px} p.p7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p8 {margin: 0.0px 0.0px 0.0px 36.0px; text-indent: -36.0px; font: 14.0px Times; min-height: 18.0px} p.p9 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; min-height: 18.0px} p.p10 {margin: 0.0px 0.0px 12.0px 0.0px; font: 14.0px Times; color: #000000} li.li1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times} li.li7 {margin: 0.0px 0.0px 0.0px 0.0px; font: 14.0px Times; min-height: 18.0px} span.s1 {font: 14.0px Courier} span.s2 {color: #000000} span.s3 {font: 14.0px Courier; color: #000000} ol.ol1 {list-style-type: decimal} Or, enduring values for a changing world. Introduction A value type is a data type which, generally speaking, is designed for being passed by value in and out of methods, and stored by value in data structures. The only value types which the Java language directly supports are the eight primitive types. Java indirectly and approximately supports value types, if they are implemented in terms of classes. For example, both Integer and String may be viewed as value types, especially if their usage is restricted to avoid operations appropriate to Object. In this note, we propose a definition of value types in terms of a design pattern for Java classes, accompanied by a set of usage restrictions. We also sketch the relation of such value types to tuple types (which are a JVM-level notion), and point out JVM optimizations that can apply to value types. This note is a thought experiment to extend the JVM’s performance model in support of value types. The demonstration has two phases.  Initially the extension can simply use design patterns, within the current bytecode architecture, and in today’s Java language. But if the performance model is to be realized in practice, it will probably require new JVM bytecode features, changes to the Java language, or both.  We will look at a few possibilities for these new features. An Axiom of Value In the context of the JVM, a value type is a data type equipped with construction, assignment, and equality operations, and a set of typed components, such that, whenever two variables of the value type produce equal corresponding values for their components, the values of the two variables cannot be distinguished by any JVM operation. Here are some corollaries: A value type is immutable, since otherwise a copy could be constructed and the original could be modified in one of its components, allowing the copies to be distinguished. Changing the component of a value type requires construction of a new value. The equals and hashCode operations are strictly component-wise. If a value type is represented by a JVM reference, that reference cannot be successfully synchronized on, and cannot be usefully compared for reference equality. A value type can be viewed in terms of what it doesn’t do. We can say that a value type omits all value-unsafe operations, which could violate the constraints on value types.  These operations, which are ordinarily allowed for Java object types, are pointer equality comparison (the acmp instruction), synchronization (the monitor instructions), all the wait and notify methods of class Object, and non-trivial finalize methods. The clone method is also value-unsafe, although for value types it could be treated as the identity function. Finally, and most importantly, any side effect on an object (however visible) also counts as an value-unsafe operation. A value type may have methods, but such methods must not change the components of the value. It is reasonable and useful to define methods like toString, equals, and hashCode on value types, and also methods which are specifically valuable to users of the value type. Representations of Value Value types have two natural representations in the JVM, unboxed and boxed. An unboxed value consists of the components, as simple variables. For example, the complex number x=(1+2i), in rectangular coordinate form, may be represented in unboxed form by the following pair of variables: /*Complex x = Complex.valueOf(1.0, 2.0):*/ double x_re = 1.0, x_im = 2.0; These variables might be locals, parameters, or fields. Their association as components of a single value is not defined to the JVM. Here is a sample computation which computes the norm of the difference between two complex numbers: double distance(/*Complex x:*/ double x_re, double x_im,         /*Complex y:*/ double y_re, double y_im) {     /*Complex z = x.minus(y):*/     double z_re = x_re - y_re, z_im = x_im - y_im;     /*return z.abs():*/     return Math.sqrt(z_re*z_re + z_im*z_im); } A boxed representation groups component values under a single object reference. The reference is to a ‘wrapper class’ that carries the component values in its fields. (A primitive type can naturally be equated with a trivial value type with just one component of that type. In that view, the wrapper class Integer can serve as a boxed representation of value type int.) The unboxed representation of complex numbers is practical for many uses, but it fails to cover several major use cases: return values, array elements, and generic APIs. The two components of a complex number cannot be directly returned from a Java function, since Java does not support multiple return values. The same story applies to array elements: Java has no ’array of structs’ feature. (Double-length arrays are a possible workaround for complex numbers, but not for value types with heterogeneous components.) By generic APIs I mean both those which use generic types, like Arrays.asList and those which have special case support for primitive types, like String.valueOf and PrintStream.println. Those APIs do not support unboxed values, and offer some problems to boxed values. Any ’real’ JVM type should have a story for returns, arrays, and API interoperability. The basic problem here is that value types fall between primitive types and object types. Value types are clearly more complex than primitive types, and object types are slightly too complicated. Objects are a little bit dangerous to use as value carriers, since object references can be compared for pointer equality, and can be synchronized on. Also, as many Java programmers have observed, there is often a performance cost to using wrapper objects, even on modern JVMs. Even so, wrapper classes are a good starting point for talking about value types. If there were a set of structural rules and restrictions which would prevent value-unsafe operations on value types, wrapper classes would provide a good notation for defining value types. This note attempts to define such rules and restrictions. Let’s Start Coding Now it is time to look at some real code. Here is a definition, written in Java, of a complex number value type. @ValueSafe public final class Complex implements java.io.Serializable {     // immutable component structure:     public final double re, im;     private Complex(double re, double im) {         this.re = re; this.im = im;     }     // interoperability methods:     public String toString() { return "Complex("+re+","+im+")"; }     public List<Double> asList() { return Arrays.asList(re, im); }     public boolean equals(Complex c) {         return re == c.re && im == c.im;     }     public boolean equals(@ValueSafe Object x) {         return x instanceof Complex && equals((Complex) x);     }     public int hashCode() {         return 31*Double.valueOf(re).hashCode()                 + Double.valueOf(im).hashCode();     }     // factory methods:     public static Complex valueOf(double re, double im) {         return new Complex(re, im);     }     public Complex changeRe(double re2) { return valueOf(re2, im); }     public Complex changeIm(double im2) { return valueOf(re, im2); }     public static Complex cast(@ValueSafe Object x) {         return x == null ? ZERO : (Complex) x;     }     // utility methods and constants:     public Complex plus(Complex c)  { return new Complex(re+c.re, im+c.im); }     public Complex minus(Complex c) { return new Complex(re-c.re, im-c.im); }     public double abs() { return Math.sqrt(re*re + im*im); }     public static final Complex PI = valueOf(Math.PI, 0.0);     public static final Complex ZERO = valueOf(0.0, 0.0); } This is not a minimal definition, because it includes some utility methods and other optional parts.  The essential elements are as follows: The class is marked as a value type with an annotation. The class is final, because it does not make sense to create subclasses of value types. The fields of the class are all non-private and final.  (I.e., the type is immutable and structurally transparent.) From the supertype Object, all public non-final methods are overridden. The constructor is private. Beyond these bare essentials, we can observe the following features in this example, which are likely to be typical of all value types: One or more factory methods are responsible for value creation, including a component-wise valueOf method. There are utility methods for complex arithmetic and instance creation, such as plus and changeIm. There are static utility constants, such as PI. The type is serializable, using the default mechanisms. There are methods for converting to and from dynamically typed references, such as asList and cast. The Rules In order to use value types properly, the programmer must avoid value-unsafe operations.  A helpful Java compiler should issue errors (or at least warnings) for code which provably applies value-unsafe operations, and should issue warnings for code which might be correct but does not provably avoid value-unsafe operations.  No such compilers exist today, but to simplify our account here, we will pretend that they do exist. A value-safe type is any class, interface, or type parameter marked with the @ValueSafe annotation, or any subtype of a value-safe type.  If a value-safe class is marked final, it is in fact a value type.  All other value-safe classes must be abstract.  The non-static fields of a value class must be non-public and final, and all its constructors must be private. Under the above rules, a standard interface could be helpful to define value types like Complex.  Here is an example: @ValueSafe public interface ValueType extends java.io.Serializable {     // All methods listed here must get redefined.     // Definitions must be value-safe, which means     // they may depend on component values only.     List<? extends Object> asList();     int hashCode();     boolean equals(@ValueSafe Object c);     String toString(); } //@ValueSafe inherited from supertype: public final class Complex implements ValueType { … The main advantage of such a conventional interface is that (unlike an annotation) it is reified in the runtime type system.  It could appear as an element type or parameter bound, for facilities which are designed to work on value types only.  More broadly, it might assist the JVM to perform dynamic enforcement of the rules for value types. Besides types, the annotation @ValueSafe can mark fields, parameters, local variables, and methods.  (This is redundant when the type is also value-safe, but may be useful when the type is Object or another supertype of a value type.)  Working forward from these annotations, an expression E is defined as value-safe if it satisfies one or more of the following: The type of E is a value-safe type. E names a field, parameter, or local variable whose declaration is marked @ValueSafe. E is a call to a method whose declaration is marked @ValueSafe. E is an assignment to a value-safe variable, field reference, or array reference. E is a cast to a value-safe type from a value-safe expression. E is a conditional expression E0 ? E1 : E2, and both E1 and E2 are value-safe. Assignments to value-safe expressions and initializations of value-safe names must take their values from value-safe expressions. A value-safe expression may not be the subject of a value-unsafe operation.  In particular, it cannot be synchronized on, nor can it be compared with the “==” operator, not even with a null or with another value-safe type. In a program where all of these rules are followed, no value-type value will be subject to a value-unsafe operation.  Thus, the prime axiom of value types will be satisfied, that no two value type will be distinguishable as long as their component values are equal. More Code To illustrate these rules, here are some usage examples for Complex: Complex pi = Complex.valueOf(Math.PI, 0); Complex zero = pi.changeRe(0);  //zero = pi; zero.re = 0; ValueType vtype = pi; @SuppressWarnings("value-unsafe")   Object obj = pi; @ValueSafe Object obj2 = pi; obj2 = new Object();  // ok List<Complex> clist = new ArrayList<Complex>(); clist.add(pi);  // (ok assuming List.add param is @ValueSafe) List<ValueType> vlist = new ArrayList<ValueType>(); vlist.add(pi);  // (ok) List<Object> olist = new ArrayList<Object>(); olist.add(pi);  // warning: "value-unsafe" boolean z = pi.equals(zero); boolean z1 = (pi == zero);  // error: reference comparison on value type boolean z2 = (pi == null);  // error: reference comparison on value type boolean z3 = (pi == obj2);  // error: reference comparison on value type synchronized (pi) { }  // error: synch of value, unpredictable result synchronized (obj2) { }  // unpredictable result Complex qq = pi; qq = null;  // possible NPE; warning: “null-unsafe" qq = (Complex) obj;  // warning: “null-unsafe" qq = Complex.cast(obj);  // OK @SuppressWarnings("null-unsafe")   Complex empty = null;  // possible NPE qq = empty;  // possible NPE (null pollution) The Payoffs It follows from this that either the JVM or the java compiler can replace boxed value-type values with unboxed ones, without affecting normal computations.  Fields and variables of value types can be split into their unboxed components.  Non-static methods on value types can be transformed into static methods which take the components as value parameters. Some common questions arise around this point in any discussion of value types. Why burden the programmer with all these extra rules?  Why not detect programs automagically and perform unboxing transparently?  The answer is that it is easy to break the rules accidently unless they are agreed to by the programmer and enforced.  Automatic unboxing optimizations are tantalizing but (so far) unreachable ideal.  In the current state of the art, it is possible exhibit benchmarks in which automatic unboxing provides the desired effects, but it is not possible to provide a JVM with a performance model that assures the programmer when unboxing will occur.  This is why I’m writing this note, to enlist help from, and provide assurances to, the programmer.  Basically, I’m shooting for a good set of user-supplied “pragmas” to frame the desired optimization. Again, the important thing is that the unboxing must be done reliably, or else programmers will have no reason to work with the extra complexity of the value-safety rules.  There must be a reasonably stable performance model, wherein using a value type has approximately the same performance characteristics as writing the unboxed components as separate Java variables. There are some rough corners to the present scheme.  Since Java fields and array elements are initialized to null, value-type computations which incorporate uninitialized variables can produce null pointer exceptions.  One workaround for this is to require such variables to be null-tested, and the result replaced with a suitable all-zero value of the value type.  That is what the “cast” method does above. Generically typed APIs like List<T> will continue to manipulate boxed values always, at least until we figure out how to do reification of generic type instances.  Use of such APIs will elicit warnings until their type parameters (and/or relevant members) are annotated or typed as value-safe.  Retrofitting List<T> is likely to expose flaws in the present scheme, which we will need to engineer around.  Here are a couple of first approaches: public interface java.util.List<@ValueSafe T> extends Collection<T> { … public interface java.util.List<T extends Object|ValueType> extends Collection<T> { … (The second approach would require disjunctive types, in which value-safety is “contagious” from the constituent types.) With more transformations, the return value types of methods can also be unboxed.  This may require significant bytecode-level transformations, and would work best in the presence of a bytecode representation for multiple value groups, which I have proposed elsewhere under the title “Tuples in the VM”. But for starters, the JVM can apply this transformation under the covers, to internally compiled methods.  This would give a way to express multiple return values and structured return values, which is a significant pain-point for Java programmers, especially those who work with low-level structure types favored by modern vector and graphics processors.  The lack of multiple return values has a strong distorting effect on many Java APIs. Even if the JVM fails to unbox a value, there is still potential benefit to the value type.  Clustered computing systems something have copy operations (serialization or something similar) which apply implicitly to command operands.  When copying JVM objects, it is extremely helpful to know when an object’s identity is important or not.  If an object reference is a copied operand, the system may have to create a proxy handle which points back to the original object, so that side effects are visible.  Proxies must be managed carefully, and this can be expensive.  On the other hand, value types are exactly those types which a JVM can “copy and forget” with no downside. Array types are crucial to bulk data interfaces.  (As data sizes and rates increase, bulk data becomes more important than scalar data, so arrays are definitely accompanying us into the future of computing.)  Value types are very helpful for adding structure to bulk data, so a successful value type mechanism will make it easier for us to express richer forms of bulk data. Unboxing arrays (i.e., arrays containing unboxed values) will provide better cache and memory density, and more direct data movement within clustered or heterogeneous computing systems.  They require the deepest transformations, relative to today’s JVM.  There is an impedance mismatch between value-type arrays and Java’s covariant array typing, so compromises will need to be struck with existing Java semantics.  It is probably worth the effort, since arrays of unboxed value types are inherently more memory-efficient than standard Java arrays, which rely on dependent pointer chains. It may be sufficient to extend the “value-safe” concept to array declarations, and allow low-level transformations to change value-safe array declarations from the standard boxed form into an unboxed tuple-based form.  Such value-safe arrays would not be convertible to Object[] arrays.  Certain connection points, such as Arrays.copyOf and System.arraycopy might need additional input/output combinations, to allow smooth conversion between arrays with boxed and unboxed elements. Alternatively, the correct solution may have to wait until we have enough reification of generic types, and enough operator overloading, to enable an overhaul of Java arrays. Implicit Method Definitions The example of class Complex above may be unattractively complex.  I believe most or all of the elements of the example class are required by the logic of value types. If this is true, a programmer who writes a value type will have to write lots of error-prone boilerplate code.  On the other hand, I think nearly all of the code (except for the domain-specific parts like plus and minus) can be implicitly generated. Java has a rule for implicitly defining a class’s constructor, if no it defines no constructors explicitly.  Likewise, there are rules for providing default access modifiers for interface members.  Because of the highly regular structure of value types, it might be reasonable to perform similar implicit transformations on value types.  Here’s an example of a “highly implicit” definition of a complex number type: public class Complex implements ValueType {  // implicitly final     public double re, im;  // implicitly public final     //implicit methods are defined elementwise from te fields:     //  toString, asList, equals(2), hashCode, valueOf, cast     //optionally, explicit methods (plus, abs, etc.) would go here } In other words, with the right defaults, a simple value type definition can be a one-liner.  The observant reader will have noticed the similarities (and suitable differences) between the explicit methods above and the corresponding methods for List<T>. Another way to abbreviate such a class would be to make an annotation the primary trigger of the functionality, and to add the interface(s) implicitly: public @ValueType class Complex { … // implicitly final, implements ValueType (But to me it seems better to communicate the “magic” via an interface, even if it is rooted in an annotation.) Implicitly Defined Value Types So far we have been working with nominal value types, which is to say that the sequence of typed components is associated with a name and additional methods that convey the intention of the programmer.  A simple ordered pair of floating point numbers can be variously interpreted as (to name a few possibilities) a rectangular or polar complex number or Cartesian point.  The name and the methods convey the intended meaning. But what if we need a truly simple ordered pair of floating point numbers, without any further conceptual baggage?  Perhaps we are writing a method (like “divideAndRemainder”) which naturally returns a pair of numbers instead of a single number.  Wrapping the pair of numbers in a nominal type (like “QuotientAndRemainder”) makes as little sense as wrapping a single return value in a nominal type (like “Quotient”).  What we need here are structural value types commonly known as tuples. For the present discussion, let us assign a conventional, JVM-friendly name to tuples, roughly as follows: public class java.lang.tuple.$DD extends java.lang.tuple.Tuple {      double $1, $2; } Here the component names are fixed and all the required methods are defined implicitly.  The supertype is an abstract class which has suitable shared declarations.  The name itself mentions a JVM-style method parameter descriptor, which may be “cracked” to determine the number and types of the component fields. The odd thing about such a tuple type (and structural types in general) is it must be instantiated lazily, in response to linkage requests from one or more classes that need it.  The JVM and/or its class loaders must be prepared to spin a tuple type on demand, given a simple name reference, $xyz, where the xyz is cracked into a series of component types.  (Specifics of naming and name mangling need some tasteful engineering.) Tuples also seem to demand, even more than nominal types, some support from the language.  (This is probably because notations for non-nominal types work best as combinations of punctuation and type names, rather than named constructors like Function3 or Tuple2.)  At a minimum, languages with tuples usually (I think) have some sort of simple bracket notation for creating tuples, and a corresponding pattern-matching syntax (or “destructuring bind”) for taking tuples apart, at least when they are parameter lists.  Designing such a syntax is no simple thing, because it ought to play well with nominal value types, and also with pre-existing Java features, such as method parameter lists, implicit conversions, generic types, and reflection.  That is a task for another day. Other Use Cases Besides complex numbers and simple tuples there are many use cases for value types.  Many tuple-like types have natural value-type representations. These include rational numbers, point locations and pixel colors, and various kinds of dates and addresses. Other types have a variable-length ‘tail’ of internal values. The most common example of this is String, which is (mathematically) a sequence of UTF-16 character values. Similarly, bit vectors, multiple-precision numbers, and polynomials are composed of sequences of values. Such types include, in their representation, a reference to a variable-sized data structure (often an array) which (somehow) represents the sequence of values. The value type may also include ’header’ information. Variable-sized values often have a length distribution which favors short lengths. In that case, the design of the value type can make the first few values in the sequence be direct ’header’ fields of the value type. In the common case where the header is enough to represent the whole value, the tail can be a shared null value, or even just a null reference. Note that the tail need not be an immutable object, as long as the header type encapsulates it well enough. This is the case with String, where the tail is a mutable (but never mutated) character array. Field types and their order must be a globally visible part of the API.  The structure of the value type must be transparent enough to have a globally consistent unboxed representation, so that all callers and callees agree about the type and order of components  that appear as parameters, return types, and array elements.  This is a trade-off between efficiency and encapsulation, which is forced on us when we remove an indirection enjoyed by boxed representations.  A JVM-only transformation would not care about such visibility, but a bytecode transformation would need to take care that (say) the components of complex numbers would not get swapped after a redefinition of Complex and a partial recompile.  Perhaps constant pool references to value types need to declare the field order as assumed by each API user. This brings up the delicate status of private fields in a value type.  It must always be possible to load, store, and copy value types as coordinated groups, and the JVM performs those movements by moving individual scalar values between locals and stack.  If a component field is not public, what is to prevent hostile code from plucking it out of the tuple using a rogue aload or astore instruction?  Nothing but the verifier, so we may need to give it more smarts, so that it treats value types as inseparable groups of stack slots or locals (something like long or double). My initial thought was to make the fields always public, which would make the security problem moot.  But public is not always the right answer; consider the case of String, where the underlying mutable character array must be encapsulated to prevent security holes.  I believe we can win back both sides of the tradeoff, by training the verifier never to split up the components in an unboxed value.  Just as the verifier encapsulates the two halves of a 64-bit primitive, it can encapsulate the the header and body of an unboxed String, so that no code other than that of class String itself can take apart the values. Similar to String, we could build an efficient multi-precision decimal type along these lines: public final class DecimalValue extends ValueType {     protected final long header;     protected private final BigInteger digits;     public DecimalValue valueOf(int value, int scale) {         assert(scale >= 0);         return new DecimalValue(((long)value << 32) + scale, null);     }     public DecimalValue valueOf(long value, int scale) {         if (value == (int) value)             return valueOf((int)value, scale);         return new DecimalValue(-scale, new BigInteger(value));     } } Values of this type would be passed between methods as two machine words. Small values (those with a significand which fits into 32 bits) would be represented without any heap data at all, unless the DecimalValue itself were boxed. (Note the tension between encapsulation and unboxing in this case.  It would be better if the header and digits fields were private, but depending on where the unboxing information must “leak”, it is probably safer to make a public revelation of the internal structure.) Note that, although an array of Complex can be faked with a double-length array of double, there is no easy way to fake an array of unboxed DecimalValues.  (Either an array of boxed values or a transposed pair of homogeneous arrays would be reasonable fallbacks, in a current JVM.)  Getting the full benefit of unboxing and arrays will require some new JVM magic. Although the JVM emphasizes portability, system dependent code will benefit from using machine-level types larger than 64 bits.  For example, the back end of a linear algebra package might benefit from value types like Float4 which map to stock vector types.  This is probably only worthwhile if the unboxing arrays can be packed with such values. More Daydreams A more finely-divided design for dynamic enforcement of value safety could feature separate marker interfaces for each invariant.  An empty marker interface Unsynchronizable could cause suitable exceptions for monitor instructions on objects in marked classes.  More radically, a Interchangeable marker interface could cause JVM primitives that are sensitive to object identity to raise exceptions; the strangest result would be that the acmp instruction would have to be specified as raising an exception. @ValueSafe public interface ValueType extends java.io.Serializable,         Unsynchronizable, Interchangeable { … public class Complex implements ValueType {     // inherits Serializable, Unsynchronizable, Interchangeable, @ValueSafe     … It seems possible that Integer and the other wrapper types could be retro-fitted as value-safe types.  This is a major change, since wrapper objects would be unsynchronizable and their references interchangeable.  It is likely that code which violates value-safety for wrapper types exists but is uncommon.  It is less plausible to retro-fit String, since the prominent operation String.intern is often used with value-unsafe code. We should also reconsider the distinction between boxed and unboxed values in code.  The design presented above obscures that distinction.  As another thought experiment, we could imagine making a first class distinction in the type system between boxed and unboxed representations.  Since only primitive types are named with a lower-case initial letter, we could define that the capitalized version of a value type name always refers to the boxed representation, while the initial lower-case variant always refers to boxed.  For example: complex pi = complex.valueOf(Math.PI, 0); Complex boxPi = pi;  // convert to boxed myList.add(boxPi); complex z = myList.get(0);  // unbox Such a convention could perhaps absorb the current difference between int and Integer, double and Double. It might also allow the programmer to express a helpful distinction among array types. As said above, array types are crucial to bulk data interfaces, but are limited in the JVM.  Extending arrays beyond the present limitations is worth thinking about; for example, the Maxine JVM implementation has a hybrid object/array type.  Something like this which can also accommodate value type components seems worthwhile.  On the other hand, does it make sense for value types to contain short arrays?  And why should random-access arrays be the end of our design process, when bulk data is often sequentially accessed, and it might make sense to have heterogeneous streams of data as the natural “jumbo” data structure.  These considerations must wait for another day and another note. More Work It seems to me that a good sequence for introducing such value types would be as follows: Add the value-safety restrictions to an experimental version of javac. Code some sample applications with value types, including Complex and DecimalValue. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. A staggered roll-out like this would decouple language changes from bytecode changes, which is always a convenient thing. A similar investigation should be applied (concurrently) to array types.  In this case, it seems to me that the starting point is in the JVM: Add an experimental unboxing array data structure to a production JVM, perhaps along the lines of Maxine hybrids.  No bytecode or language support is required at first; everything can be done with encapsulated unsafe operations and/or method handles. Create an experimental JVM which internally unboxes value types but does not require new bytecodes to do so.  Ensure the feasibility of the performance model for the sample applications. Add tuple-like bytecodes (with or without generic type reification) to a major revision of the JVM, and teach the Java compiler to switch in the new bytecodes without code changes. That’s enough musing me for now.  Back to work!

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  • TOTD #165: Eclipse Indigo, Java EE 6 and GlassFish

    - by arungupta
    46 millions lines of code committed by 408 developers from 49 organizations is the recipe for Indigo, the sixth release as part of the Eclipse annual release train. The key features of this release are: EGit 1.0 enabling Git support WindowBuilder, a GUI Builder Jubula for automated functional testing for Java and HTML EclipseLink 2.3 with support for multi-tenant JPA entities Equinox 3.7 with OSGi 4.3 specs Read the complete list of improvements here and download now! An updated version of the GlassFish plugin is also pushed to the update center and can be downloaded by clicking on "Additional Server Adapters" and selecting GlassFish as shown below: Couple of much needed improvements in the plugin are: Configurable "Preserve Sessions across Re-deploys" by double-clicking on the server properties: This property could only be configured during server registeration in earlier versions. Richer management of GlassFish from within the IDE such as viewing all the resources (JDBC, Connectors, and JavaMail) as shown below: The screencast #36 shows complete Java EE 6 development using GlassFish and the video is  embedded here for convenience: This blog has published multiple entries on Eclipse and here are some of them: Eclipse Con 2011 Hands-on Lab delivered: OSGi, JavaEE, GlassFish, Eclipse a powerful foursome Screencast #38: "Developing OSGi-enabled Java EE Applications using GlassFish" Tutorial at EclipseCon 2011 Screencast #36: Web App Development using Java EE 6, GlassFish, and Eclipse - Webinar Recording Screencast #31: Java EE 6 using GlassFish and Eclipse 3.6 - Oracle Enterprise Pack for Eclipse 11.1.1.6 is now available - 5 new screencasts TOTD #127: Embedding GlassFish in an existing OSGi runtime - Eclipse Equinox TOTD #126: Creating an OSGi bundles using Eclipse and deploying in GlassFish

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  • TOTD #165: Eclipse Indigo, Java EE 6 and GlassFish

    - by arungupta
    46 millions lines of code committed by 408 developers from 49 organizations is the recipe for Indigo, the sixth release as part of the Eclipse annual release train. The key features of this release are: EGit 1.0 enabling Git support WindowBuilder, a GUI Builder Jubula for automated functional testing for Java and HTML EclipseLink 2.3 with support for multi-tenant JPA entities Equinox 3.7 with OSGi 4.3 specs Read the complete list of improvements here and download now! An updated version of the GlassFish plugin is also pushed to the update center and can be downloaded by clicking on "Additional Server Adapters" and selecting GlassFish as shown below: Couple of much needed improvements in the plugin are: Configurable "Preserve Sessions across Re-deploys" by double-clicking on the server properties: This property could only be configured during server registeration in earlier versions. Richer management of GlassFish from within the IDE such as viewing all the resources (JDBC, Connectors, and JavaMail) as shown below: The screencast #36 shows complete Java EE 6 development using GlassFish and the video is  embedded here for convenience: This blog has published multiple entries on Eclipse and here are some of them: Eclipse Con 2011 Hands-on Lab delivered: OSGi, JavaEE, GlassFish, Eclipse a powerful foursome Screencast #38: "Developing OSGi-enabled Java EE Applications using GlassFish" Tutorial at EclipseCon 2011 Screencast #36: Web App Development using Java EE 6, GlassFish, and Eclipse - Webinar Recording Screencast #31: Java EE 6 using GlassFish and Eclipse 3.6 - Oracle Enterprise Pack for Eclipse 11.1.1.6 is now available - 5 new screencasts TOTD #127: Embedding GlassFish in an existing OSGi runtime - Eclipse Equinox TOTD #126: Creating an OSGi bundles using Eclipse and deploying in GlassFish

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  • OpenGL ES 2 shaders for drawing buildings and roads like Google Maps does

    - by Pris
    I'm trying to create a shader that'll give me an effect similar to what buildings and roads look like on 3D Google Maps. You can see the effect interactively if you enable WebGL at maps.google.com, and I also found a couple of screenshots that illustrate what I'm trying to achieve: Thing I noticed: There's some kind of transparency thing going on with the roads/ground and the buildings, but not between the buildings themselves. It might be that they're rendering the ground and roads after the buildings with the right blend functions to achieve that effect. If you look closely, you'll see parts of the building profiles have an outline. The roads also have nice clean outlines. There are a lot of techniques for outlining things with shaders... but I'm curious to find out what might have been used in this case considering mobile hardware and a large number of entities with outlines (roads and buildings) I'm assuming that for the lighting, some sort of simple diffuse per-vertex shader is being used for the buildings though I could be wrong. I'm especially curious about the 'look' they achieved with buildings (clean, precise outlines/shading). It reminds me a little of what you'd see when designing stuff with CAD applications like SolidWorks: I'd appreciate any advice on achieving this kind of look with ES 2 shaders.

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  • Designing a social network with CQRS, graph databases and relational databases in mind

    - by Siraj Mansour
    I have done quite an amount of research on the topic so far, but i couldn't come up with a conclusion to make up my mind. I am designing a social network and during my research i stumbled upon graph databases, i found neo4j pretty interesting for user relations and traversing through nodes. I also thought of using a relational database such as MS-SQL or MySQL to store entity data only and depending on neo4j for connections between entities. Of course this means more work in my application to store and pull data in and out of 2 different sources. My first question : Is using this approach (graph + relational) a good approach for designing my social network keeping in mind that users on social networks don't have to in synch with real data by split second ? What are the positives and negatives of this approach ? My Second question : I've been doing some reading on CQRS and as i understood it is mostly useful for collaborative environments, and environments where users see a lot of "stale" data. social networks has shared comments, events, etc .. and many users query or update the same data. Could CQRS be a helpful approach ? Would it give any performance/scalability benefits or non-useful complexity ? Is it fairly applicable with my possible choice of (graph + relational) databases approach mentioned in the question above ? My purpose is to know if the approaches i have mentioned above seem good enough for the business context.

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  • Caching NHibernate Named Queries

    - by TStewartDev
    I recently started a new job and one of my first tasks was to implement a "popular products" design. The parameters were that it be done with NHibernate and be cached for 24 hours at a time because the query will be pretty taxing and the results do not need to be constantly up to date. This ended up being tougher than it sounds. The database schema meant a minimum of four joins with filtering and ordering criteria. I decided to use a stored procedure rather than letting NHibernate create the SQL for me. Here is a summary of what I learned (even if I didn't ultimately use all of it): You can't, at the time of this writing, use Fluent NHibernate to configure SQL named queries or imports You can return persistent entities from a stored procedure and there are a couple ways to do that You can populate POCOs using the results of a stored procedure, but it isn't quite as obvious You can reuse your named query result mapping other places (avoid duplication) Caching your query results is not at all obvious Testing to see if your cache is working is a pain NHibernate does a lot of things right. Having unified, up-to-date, comprehensive, and easy-to-find documentation is not one of them. By the way, if you're new to this, I'll use the terms "named query" and "stored procedure" (from NHibernate's perspective) fairly interchangeably. Technically, a named query can execute any SQL, not just a stored procedure, and a stored procedure doesn't have to be executed from a named query, but for reusability, it seems to me like the best practice. If you're here, chances are good you're looking for answers to a similar problem. You don't want to read about the path, you just want the result. So, here's how to get this thing going. The Stored Procedure NHibernate has some guidelines when using stored procedures. For Microsoft SQL Server, you have to return a result set. The scalar value that the stored procedure returns is ignored as are any result sets after the first. Other than that, it's nothing special. CREATE PROCEDURE GetPopularProducts @StartDate DATETIME, @MaxResults INT AS BEGIN SELECT [ProductId], [ProductName], [ImageUrl] FROM SomeTableWithJoinsEtc END The Result Class - PopularProduct You have two options to transport your query results to your view (or wherever is the final destination): you can populate an existing mapped entity class in your model, or you can create a new entity class. If you go with the existing model, the advantage is that the query will act as a loader and you'll get full proxied access to the domain model. However, this can be a disadvantage if you require access to the related entities that aren't loaded by your results. For example, my PopularProduct has image references. Unless I tie them into the query (thus making it even more complicated and expensive to run), they'll have to be loaded on access, requiring more trips to the database. Since we're trying to avoid trips to the database by using a second-level cache, we should use the second option, which is to create a separate entity for results. This approach is (I believe) in the spirit of the Command-Query Separation principle, and it allows us to flatten our data and optimize our report-generation process from data source to view. public class PopularProduct { public virtual int ProductId { get; set; } public virtual string ProductName { get; set; } public virtual string ImageUrl { get; set; } } The NHibernate Mappings (hbm) Next up, we need to let NHibernate know about the query and where the results will go. Below is the markup for the PopularProduct class. Notice that I'm using the <resultset> element and that it has a name attribute. The name allows us to drop this into our query map and any others, giving us reusability. Also notice the <import> element which lets NHibernate know about our entity class. <?xml version="1.0" encoding="utf-8" ?> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"> <import class="PopularProduct, Infrastructure.NHibernate, Version=1.0.0.0"/> <resultset name="PopularProductResultSet"> <return-scalar column="ProductId" type="System.Int32"/> <return-scalar column="ProductName" type="System.String"/> <return-scalar column="ImageUrl" type="System.String"/> </resultset> </hibernate-mapping>  And now the PopularProductsMap: <?xml version="1.0" encoding="utf-8" ?> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"> <sql-query name="GetPopularProducts" resultset-ref="PopularProductResultSet" cacheable="true" cache-mode="normal"> <query-param name="StartDate" type="System.DateTime" /> <query-param name="MaxResults" type="System.Int32" /> exec GetPopularProducts @StartDate = :StartDate, @MaxResults = :MaxResults </sql-query> </hibernate-mapping>  The two most important things to notice here are the resultset-ref attribute, which links in our resultset mapping, and the cacheable attribute. The Query Class – PopularProductsQuery So far, this has been fairly obvious if you're familiar with NHibernate. This next part, maybe not so much. You can implement your query however you want to; for me, I wanted a self-encapsulated Query class, so here's what it looks like: public class PopularProductsQuery : IPopularProductsQuery { private static readonly IResultTransformer ResultTransformer; private readonly ISessionBuilder _sessionBuilder;   static PopularProductsQuery() { ResultTransformer = Transformers.AliasToBean<PopularProduct>(); }   public PopularProductsQuery(ISessionBuilder sessionBuilder) { _sessionBuilder = sessionBuilder; }   public IList<PopularProduct> GetPopularProducts(DateTime startDate, int maxResults) { var session = _sessionBuilder.GetSession(); var popularProducts = session .GetNamedQuery("GetPopularProducts") .SetCacheable(true) .SetCacheRegion("PopularProductsCacheRegion") .SetCacheMode(CacheMode.Normal) .SetReadOnly(true) .SetResultTransformer(ResultTransformer) .SetParameter("StartDate", startDate.Date) .SetParameter("MaxResults", maxResults) .List<PopularProduct>();   return popularProducts; } }  Okay, so let's look at each line of the query execution. The first, GetNamedQuery, matches up with our NHibernate mapping for the sql-query. Next, we set it as cacheable (this is probably redundant since our mapping also specified it, but it can't hurt, right?). Then we set the cache region which we'll get to in the next section. Set the cache mode (optional, I believe), and my cache is read-only, so I set that as well. The result transformer is very important. This tells NHibernate how to transform your query results into a non-persistent entity. You can see I've defined ResultTransformer in the static constructor using the AliasToBean transformer. The name is obviously leftover from Java/Hibernate. Finally, set your parameters and then call a result method which will execute the query. Because this is set to cached, you execute this statement every time you run the query and NHibernate will know based on your parameters whether to use its cached version or a fresh version. The Configuration – hibernate.cfg.xml and Web.config You need to explicitly enable second-level caching in your hibernate configuration: <hibernate-configuration xmlns="urn:nhibernate-configuration-2.2"> <session-factory> [...] <property name="dialect">NHibernate.Dialect.MsSql2005Dialect</property> <property name="cache.provider_class">NHibernate.Caches.SysCache.SysCacheProvider,NHibernate.Caches.SysCache</property> <property name="cache.use_query_cache">true</property> <property name="cache.use_second_level_cache">true</property> [...] </session-factory> </hibernate-configuration> Both properties "use_query_cache" and "use_second_level_cache" are necessary. As this is for a web deployement, we're using SysCache which relies on ASP.NET's caching. Be aware of this if you're not deploying to the web! You'll have to use a different cache provider. We also need to tell our cache provider (in this cache, SysCache) about our caching region: <syscache> <cache region="PopularProductsCacheRegion" expiration="86400" priority="5" /> </syscache> Here I've set the cache to be valid for 24 hours. This XML snippet goes in your Web.config (or in a separate file referenced by Web.config, which helps keep things tidy). The Payoff That should be it! At this point, your queries should run once against the database for a given set of parameters and then use the cache thereafter until it expires. You can, of course, adjust settings to work in your particular environment. Testing Testing your application to ensure it is using the cache is a pain, but if you're like me, you want to know that it's actually working. It's a bit involved, though, so I'll create a separate post for it if comments indicate there is interest.

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