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• Code refactoring with Visual Studio 2010 Part-4

  - by Jalpesh P. Vadgama

  I have been writing few post with code refactoring features in Visual Studio 2010. This post also will be part of series and this post will be last of the series. In this post I am going explain two features 1) Encapsulate Field and 2) Extract Interface. Let’s explore both features in details. Encapsulate Field: This is a nice code refactoring feature provides by Visual Studio 2010. With help of this feature we can create properties from the existing private field of the class. Let’s take a simple example of Customer Class. In that I there are two private field called firstName and lastName. Below is the code for the class. public class Customer { private string firstName; private string lastName; public string Address { get; set; } public string City { get; set; } } Now lets encapsulate first field firstName with Encapsulate feature. So first select that field and goto refactor menu in Visual Studio 2010 and click on Encapsulate Field. Once you click that a dialog box will appear like following. Now once you click OK a preview dialog box will open as we have selected preview reference changes. I think its a good options to check that option to preview code that is being changed by IDE itself. Dialog will look like following. Once you click apply it create a new property called FirstName. Same way I have done for the lastName and now my customer class code look like following. public class Customer { private string firstName; public string FirstName { get { return firstName; } set { firstName = value; } } private string lastName; public string LastName { get { return lastName; } set { lastName = value; } } public string Address { get; set; } public string City { get; set; } } So you can see that its very easy to create properties with existing fields and you don’t have to change anything there in code it will change all the stuff itself. Extract Interface: When you are writing software prototype and You don’t know the future implementation of that then its a good practice to use interface there. I am going to explain here that How we can extract interface from the existing code without writing a single line of code with the help of code refactoring feature of Visual Studio 2010. For that I have create a Simple Repository class called CustomerRepository with three methods like following. public class CustomerRespository { public void Add() { // Some code to add customer } public void Update() { //some code to update customer } public void Delete() { //some code delete customer } } In above class there are three method Add,Update and Delete where we are going to implement some code for each one. Now I want to create a interface which I can use for my other entities in project. So let’s create a interface from the above class with the help of Visual Studio 2010. So first select class and goto refactor menu and click Extract Interface. It will open up dialog box like following. Here I have selected all the method for interface and Once I click OK then it will create a new file called ICustomerRespository where it has created a interface. Just like following. Here is a code for that interface. using System; namespace CodeRefractoring { interface ICustomerRespository { void Add(); void Delete(); void Update(); } } Now let's see the code for the our class. It will also changed like following to implement the interface. public class CustomerRespository : ICustomerRespository { public void Add() { // Some code to add customer } public void Update() { //some code to update customer } public void Delete() { //some code delete customer } } Isn't that great we have created a interface and implemented it without writing a single line of code. Hope you liked it. Stay tuned for more.. Till that Happy Programming.

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• Breaking 1NF to model subset constraints. Does this sound sane?

  - by Chris Travers

  My first question here. Appologize if it is in the wrong forum but this seems pretty conceptual. I am looking at doing something that goes against conventional wisdom and want to get some feedback as to whether this is totally insane or will result in problems, so critique away! I am on PostgreSQL 9.1 but may be moving to 9.2 for this part of this project. To re-iterate: Does it seem sane to break 1NF in this way? I am not looking for debugging code so much as where people see problems that this might lead. The Problem In double entry accounting, financial transactions are journal entries with an arbitrary number of lines. Each line has either a left value (debit) or a right value (credit) which can be modelled as a single value with negatives as debits and positives as credits or vice versa. The sum of all debits and credits must equal zero (so if we go with a single amount field, sum(amount) must equal zero for each financial journal entry). SQL-based databases, pretty much required for this sort of work, have no way to express this sort of constraint natively and so any approach to enforcing it in the database seems rather complex. The Write Model The journal entries are append only. There is a possibility we will add a delete model but it will be subject to a different set of restrictions and so is not applicable here. If and when we allow deletes, we will probably do them using a simple ON DELETE CASCADE designation on the foreign key, and require that deletes go through a dedicated stored procedure which can enforce the other constraints. So inserts and selects have to be accommodated but updates and deletes do not for this task. My Proposed Solution My proposed solution is to break first normal form and model constraints on arrays of tuples, with a trigger that breaks the rows out into another table. CREATE TABLE journal_line ( entry_id bigserial primary key, account_id int not null references account(id), journal_entry_id bigint not null, -- adding references later amount numeric not null ); I would then add "table methods" to extract debits and credits for reporting purposes: CREATE OR REPLACE FUNCTION debits(journal_line) RETURNS numeric LANGUAGE sql IMMUTABLE AS $$ SELECT CASE WHEN $1.amount < 0 THEN $1.amount * -1 ELSE NULL END; $$; CREATE OR REPLACE FUNCTION credits(journal_line) RETURNS numeric LANGUAGE sql IMMUTABLE AS $$ SELECT CASE WHEN $1.amount > 0 THEN $1.amount ELSE NULL END; $$; Then the journal entry table (simplified for this example): CREATE TABLE journal_entry ( entry_id bigserial primary key, -- no natural keys :-( journal_id int not null references journal(id), date_posted date not null, reference text not null, description text not null, journal_lines journal_line[] not null ); Then a table method and and check constraints: CREATE OR REPLACE FUNCTION running_total(journal_entry) returns numeric language sql immutable as $$ SELECT sum(amount) FROM unnest($1.journal_lines); $$; ALTER TABLE journal_entry ADD CONSTRAINT CHECK (((journal_entry.running_total) = 0)); ALTER TABLE journal_line ADD FOREIGN KEY journal_entry_id REFERENCES journal_entry(entry_id); And finally we'd have a breakout trigger: CREATE OR REPLACE FUNCTION je_breakout() RETURNS TRIGGER LANGUAGE PLPGSQL AS $$ BEGIN IF TG_OP = 'INSERT' THEN INSERT INTO journal_line (journal_entry_id, account_id, amount) SELECT NEW.id, account_id, amount FROM unnest(NEW.journal_lines); RETURN NEW; ELSE RAISE EXCEPTION 'Operation Not Allowed'; END IF; END; $$; And finally CREATE TRIGGER AFTER INSERT OR UPDATE OR DELETE ON journal_entry FOR EACH ROW EXECUTE_PROCEDURE je_breaout(); Of course the example above is simplified. There will be a status table that will track approval status allowing for separation of duties, etc. However the goal here is to prevent unbalanced transactions. Any feedback? Does this sound entirely insane? Standard Solutions? In getting to this point I have to say I have looked at four different current ERP solutions to this problems: Represent every line item as a debit and a credit against different accounts. Use of foreign keys against the line item table to enforce an eventual running total of 0 Use of constraint triggers in PostgreSQL Forcing all validation here solely through the app logic. My concerns are that #1 is pretty limiting and very hard to audit internally. It's not programmer transparent and so it strikes me as being difficult to work with in the future. The second strikes me as being very complex and required a series of contraints and foreign keys against self to make work, and therefore it strikes me as complex, hard to sort out at least in my mind, and thus hard to work with. The fourth could be done as we force all access through stored procedures anyway and this is the most common solution (have the app total things up and throw an error otherwise). However, I think proof that a constraint is followed is superior to test cases, and so the question becomes whether this in fact generates insert anomilies rather than solving them. If this is a solved problem it isn't the case that everyone agrees on the solution....

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• Upgrading to Code Based Migrations EF 4.3.1 with Connector/Net 6.6

  - by GABMARTINEZ

  Entity Framework 4.3.1 includes a new feature called code first migrations.  We are adding support for this feature in our upcoming 6.6 release of Connector/Net.  In this walk-through we'll see the workflow of code-based migrations when you have an existing application and you would like to upgrade to this EF 4.3.1 version and use this approach, so you can keep track of the changes that you do to your database.   The first thing we need to do is add the new Entity Framework 4.3.1 package to our application. This should via the NuGet package manager.  You can read more about why EF is not part of the .NET framework here. Adding EF 4.3.1 to our existing application  Inside VS 2010 go to Tools -> Library Package Manager -> Package Manager Console, this will open the Power Shell Host Window where we can work with all the EF commands. In order to install this library to your existing application you should type Install-Package EntityFramework This will make some changes to your application. So Let's check them. In your .config file you'll see a  <configSections> which contains the version you have from EntityFramework and also was added the <entityFramework> section as shown below. This section is by default configured to use SQL Express which won't be necesary for this case. So you can comment it out or leave it empty. Also please make sure you're using the Connector/Net 6.6.x version which is the one that has this support as is shown in the previous image. At this point we face one issue; in order to be able to work with Migrations we need the __MigrationHistory table that we don't have yet since our Database was created with an older version. This table is used to keep track of the changes in our model. So we need to get it in our existing Database. Getting a Migration-History table into an existing database First thing we need to do to enable migrations in our existing application is to create our configuration class which will set up the MySqlClient Provider as our SQL Generator. So we have to add it with the following code: using System.Data.Entity.Migrations;     //add this at the top of your cs file public class Configuration : DbMigrationsConfiguration<NameOfYourDbContext>  //Make sure to use the name of your existing DBContext { public Configuration() { this.AutomaticMigrationsEnabled = false; //Set Automatic migrations to false since we'll be applying the migrations manually for this case. SetSqlGenerator("MySql.Data.MySqlClient", new MySql.Data.Entity.MySqlMigrationSqlGenerator());     }   }  This code will set up our configuration that we'll be using when executing all the migrations for our application. Once we have done this we can Build our application so we can check that everything is fine. Creating our Initial Migration Now let's add our Initial Migration. In Package Manager Console, execute "add-migration InitialCreate", you can use any other name but I like to set this as our initial create for future reference. After we run this command, some changes were done in our application: A new Migrations Folder was created. A new class migration call InitialCreate which in most of the cases should have empty Up and Down methods as long as your database is up to date with your Model. Since all your entities already exists, delete all duplicated code to create any entity which exists already in your Database if there is any. I found this easier when you don't have any pending updates to do to your database. Now we have our empty migration that will make no changes in our database and represents how are all the things at the begining of our migrations.  Finally, let's create our MigrationsHistory table. Optionally you can add SQL code to delete the edmdata table which is not needed anymore. public override void Up() { // Just make sure that you used 4.1 or later version         Sql("DROP TABLE EdmMetadata"); } From our Package Manager Console let's type: Update-database; If you like to see the operations made on each Update-database command you can use the flag -verbose after the Update-database. This will make two important changes.  It will execute the Up method in the initial migration which has no changes in the database. And second, and very important,  it will create the __MigrationHistory table necessary to keep track of your changes. And next time you make a change to your database it will compare the current model to the one stored in the Model Column of this table. Conclusion The important thing of this walk through is that we must create our initial migration before we start doing any changes to our model. This way we'll be adding the necessary __MigrationsHistory table to our existing database, so we can keep our database up to date with all the changes we do in our context model using migrations. Hope you have found this information useful. Please let us know if you have any questions or comments, also please check our forums here where we keep answering questions in general for the community.  Happy MySQL/Net Coding!

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• SQL SERVER – Backing Up and Recovering the Tail End of a Transaction Log – Notes from the Field #042

  - by Pinal Dave

  [Notes from Pinal]: The biggest challenge which people face is not taking backup, but the biggest challenge is to restore a backup successfully. I have seen so many different examples where users have failed to restore their database because they made some mistake while they take backup and were not aware of the same. Tail Log backup was such an issue in earlier version of SQL Server but in the latest version of SQL Server, Microsoft team has fixed the confusion with additional information on the backup and restore screen itself. Now they have additional information, there are a few more people confused as they have no clue about this. Previously they did not find this as a issue and now they are finding tail log as a new learning. Linchpin People are database coaches and wellness experts for a data driven world. In this 42nd episode of the Notes from the Fields series database expert Tim Radney (partner at Linchpin People) explains in a very simple words, Backing Up and Recovering the Tail End of a Transaction Log. Many times when restoring a database over an existing database SQL Server will warn you about needing to make a tail end of the log backup. This might be your reminder that you have to choose to overwrite the database or could be your reminder that you are about to write over and lose any transactions since the last transaction log backup. You might be asking yourself “What is the tail end of the transaction log”. The tail end of the transaction log is simply any committed transactions that have occurred since the last transaction log backup. This is a very crucial part of a recovery strategy if you are lucky enough to be able to capture this part of the log. Most organizations have chosen to accept some amount of data loss. You might be shaking your head at this statement however if your organization is taking transaction logs backup every 15 minutes, then your potential risk of data loss is up to 15 minutes. Depending on the extent of the issue causing you to have to perform a restore, you may or may not have access to the transaction log (LDF) to be able to back up those vital transactions. For example, if the storage array or disk that holds your transaction log file becomes corrupt or damaged then you wouldn’t be able to recover the tail end of the log. If you do have access to the physical log file then you can still back up the tail end of the log. In 2013 I presented a session at the PASS Summit called “The Ultimate Tail Log Backup and Restore” and have been invited back this year to present it again. During this session I demonstrate how you can back up the tail end of the log even after the data file becomes corrupt. In my demonstration I set my database offline and then delete the data file (MDF). The database can’t become more corrupt than that. I attempt to bring the database back online to change the state to RECOVERY PENDING and then backup the tail end of the log. I can do this by specifying WITH NO_TRUNCATE. Using NO_TRUNCATE is equivalent to specifying both COPY_ONLY and CONTINUE_AFTER_ERROR. It as its name says, does not try to truncate the log. This is a great demo however how could I achieve backing up the tail end of the log if the failure destroys my entire instance of SQL and all I had was the LDF file? During my demonstration I also demonstrate that I can attach the log file to a database on another instance and then back up the tail end of the log. If I am performing proper backups then my most recent full, differential and log files should be on a server other than the one that crashed. I am able to achieve this task by creating new database with the same name as the failed database. I then set the database offline, delete my data file and overwrite the log with my good log file. I attempt to bring the database back online and then backup the log with NO_TRUNCATE just like in the first example. I encourage each of you to view my blog post and watch the video demonstration on how to perform these tasks. I really hope that none of you ever have to perform this in production, however it is a really good idea to know how to do this just in case. It really isn’t a matter of “IF” you will have to perform a restore of a production system but more of a “WHEN”. Being able to recover the tail end of the log in these sever cases could be the difference of having to notify all your business customers of data loss or not. If you want me to take a look at your server and its settings, or if your server is facing any issue we can Fix Your SQL Server. Note: Tim has also written an excellent book on SQL Backup and Recovery, a must have for everyone. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: Notes from the Field, PostADay, SQL, SQL Authority, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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• Right-Time Retail Part 2

  - by David Dorf

  This is part two of the three-part series. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Right-Time Integration Of course these real-time enabling technologies are only as good as the systems that utilize them, and it only takes one bottleneck to slow everyone else down. What good is an immediate stock-out notification if the supply chain can’t react until tomorrow? Since being formed in 2006, Oracle Retail has been not only adding more integrations between systems, but also modernizing integrations for appropriate speed. Notice I tossed in the word “appropriate.” Not everything needs to be real-time – again, we’re talking about Right-Time Retail. The speed of data capture, analysis, and execution must be synchronized or you’re wasting effort. Unfortunately, there isn’t an enterprise-wide dial that you can crank-up for your estate. You’ll need to improve things piecemeal, with people and processes as limiting factors while choosing the appropriate types of integrations. There are three integration styles we see in the retail industry. First is batch. I know, the word “batch” just sounds slow, but this pattern is less about velocity and more about volume. When there are large amounts of data to be moved, you’ll want to use batch processes. Our technology of choice here is Oracle Data Integrator (ODI), which provides a fast version of Extract-Transform-Load (ETL). Instead of the three-step process, the load and transform steps are combined to save time. ODI is a key technology for moving data into Retail Analytics where we can apply science. Performing analytics on each sale as it occurs doesn’t make any sense, so we batch up a statistically significant amount and submit all at once. The second style is fire-and-forget. For some types of data, we want the data to arrive ASAP but immediacy is not necessary. Speed is less important than guaranteed delivery, so we use message-oriented middleware available in both Weblogic and the Oracle database. For example, Point-of-Service transactions are queued for delivery to Central Office at corporate. If the network is offline, those transactions remain in the queue and will be delivered when the network returns. Transactions cannot be lost and they must be delivered in order. (Ever tried processing a return before the sale?) To enhance the standard queues, we offer the Retail Integration Bus (RIB) to help the management and monitoring of fire-and-forget messaging in the enterprise. The third style is request-response and is most commonly implemented as Web services. This is a synchronous message where the sender waits for a response. In this situation, the volume of data is small, guaranteed delivery is not necessary, but speed is very important. Examples include the website checking inventory, a price lookup, or processing a credit card authorization. The Oracle Service Bus (OSB) typically handles the routing of such messages, and we’ve enhanced its abilities with the Retail Service Backbone (RSB). To better understand these integration patterns and where they apply within the retail enterprise, we’re providing the Retail Reference Library (RRL) at no charge to Oracle Retail customers. The library is composed of a large number of industry business processes, including those necessary to support Commerce Anywhere, as well as detailed architectural diagrams. These diagrams allow implementers to understand the systems involved in integrations and the specific data payloads. Furthermore, with our upcoming release we’ll be providing a new tool called the Retail Integration Console (RIC) that allows IT to monitor and manage integrations from a single point. Using RIC, retailers can quickly discern where integration activity is occurring, volume statistics, average response times, and errors. The dashboards provide the ability to dive down into the architecture documentation to gather information all the way down to the specific payload. Retailers that want real-time integrations will also need real-time monitoring of those integrations to ensure service-level agreements are maintained. Part 3 looks at marketing.

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• ADF Reusable Artefacts

  - by Arda Eralp

  Primary reusable ADF Business Component: Entity Objects (EOs) View Objects (VOs) Application Modules (AMs) Framework Extensions Classes Primary reusable ADF Controller: Bounded Task Flows (BTFs) Task Flow Templates Primary reusable ADF Faces: Page Templates Skins Declarative Components Utility Classes Certain components will often be used more than once. Whether the reuse happens within the same application, or across different applications, it is often advantageous to package these reusable components into a library that can be shared between different developers, across different teams, and even across departments within an organization. In the world of Java object-oriented programming, reusing classes and objects is just standard procedure. With the introduction of the model-view-controller (MVC) architecture, applications can be further modularized into separate model, view, and controller layers. By separating the data (model and business services layers) from the presentation (view and controller layers), you ensure that changes to any one layer do not affect the integrity of the other layers. You can change business logic without having to change the UI, or redesign the web pages or front end without having to recode domain logic. Oracle ADF and JDeveloper support the MVC design pattern. When you create an application in JDeveloper, you can choose many application templates that automatically set up data model and user interface projects. Because the different MVC layers are decoupled from each other, development can proceed on different projects in parallel and with a certain amount of independence. ADF Library further extends this modularity of design by providing a convenient and practical way to create, deploy, and reuse high-level components. When you first design your application, you design it with component reusability in mind. If you created components that can be reused, you can package them into JAR files and add them to a reusable component repository. If you need a component, you may look into the repository for those components and then add them into your project or application. For example, you can create an application module for a domain and package it to be used as the data model project in several different applications. Or, if your application will be consuming components, you may be able to load a page template component from a repository of ADF Library JARs to create common look and feel pages. Then you can put your page flow together by stringing together several task flow components pulled from the library. An ADF Library JAR contains ADF components and does not, and cannot, contain other JARs. It should not be confused with the JDeveloper library, Java EE library, or Oracle WebLogic shared library. Reusable Component Description Data Control Any data control can be packaged into an ADF Library JAR. Some of the data controls supported by Oracle ADF include application modules, Enterprise JavaBeans, web services, URL services, JavaBeans, and placeholder data controls. Application Module When you are using ADF Business Components and you generate an application module, an associated application module data control is also generated. When you package an application module data control, you also package up the ADF Business Components associated with that application module. The relevant entity objects, view objects, and associations will be a part of the ADF Library JAR and available for reuse. Business Components Business components are the entity objects, view objects, and associations used in the ADF Business Components data model project. You can package business components by themselves or together with an application module. Task Flows & Task Flow Templates Task flows can be packaged into an ADF Library JAR for reuse. If you drop a bounded task flow that uses page fragments, JDeveloper adds a region to the page and binds it to the dropped task flow. ADF bounded task flows built using pages can be dropped onto pages. The drop will create a link to call the bounded task flow. A task flow call activity and control flow will automatically be added to the task flow, with the view activity referencing the page. If there is more than one existing task flow with a view activity referencing the page, it will prompt you to select the one to automatically add a task flow call activity and control flow. If an ADF task flow template was created in the same project as the task flow, the ADF task flow template will be included in the ADF Library JAR and will be reusable. Page Templates You can package a page template and its artifacts into an ADF Library JAR. If the template uses image files and they are included in a directory within your project, these files will also be available for the template during reuse. Declarative Components You can create declarative components and package them for reuse. The tag libraries associated with the component will be included and loaded into the consuming project. You can also package up projects that have several different reusable components if you expect that more than one component will be consumed. For example, you can create a project that has both an application module and a bounded task flow. When this ADF Library JAR file is consumed, the application will have both the application module and the task flow available for use. You can package multiple components into one JAR file, or you can package a single component into a JAR file. Oracle ADF and JDeveloper give you the option and flexibility to create reusable components that best suit you and your organization. You create a reusable component by using JDeveloper to package and deploy the project that contains the components into a ADF Library JAR file. You use the components by adding that JAR to the consuming project. At design time, the JAR is added to the consuming project's class path and so is available for reuse. At runtime, the reused component runs from the JAR file by reference.

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• Towards Ultra-Reusability for ADF - Adaptive Bindings

  - by Duncan Mills

  The task flow mechanism embodies one of the key value propositions of the ADF Framework, it's primary contribution being the componentization of your applications and implicitly the introduction of a re-use culture, particularly in large applications. However, what if we could do more? How could we make task flows even more re-usable than they are today? Well one great technique is to take advantage of a feature that is already present in the framework, a feature which I will call, for want of a better name, "adaptive bindings". What's an adaptive binding? well consider a simple use case.  I have several screens within my application which display tabular data which are all essentially identical, the only difference is that they happen to be based on different data collections (View Objects, Bean collections, whatever) , and have a different set of columns. Apart from that, however, they happen to be identical; same toolbar, same key functions and so on. So wouldn't it be nice if I could have a single parametrized task flow to represent that type of UI and reuse it? Hold on you say, great idea, however, to do that we'd run into problems. Each different collection that I want to display needs different entries in the pageDef file and: I want to continue to use the ADF Bindings mechanism rather than dropping back to passing the whole collection into the taskflow   If I do use bindings, there is no way I want to have to declare iterators and tree bindings for every possible collection that I might want the flow to handle  Ah, joy! I reply, no need to panic, you can just use adaptive bindings. Defining an Adaptive Binding  It's easiest to explain with a simple before and after use case.  Here's a basic pageDef definition for our familiar Departments table.  <executables> <iterator Binds="DepartmentsView1" DataControl="HRAppModuleDataControl" RangeSize="25"             id="DepartmentsView1Iterator"/> </executables> <bindings> <tree IterBinding="DepartmentsView1Iterator" id="DepartmentsView1">   <nodeDefinition DefName="oracle.demo.model.vo.DepartmentsView" Name="DepartmentsView10">     <AttrNames>       <Item Value="DepartmentId"/>         <Item Value="DepartmentName"/>         <Item Value="ManagerId"/>         <Item Value="LocationId"/>       </AttrNames>     </nodeDefinition> </tree> </bindings>  Here's the adaptive version: <executables> <iterator Binds="${pageFlowScope.voName}" DataControl="HRAppModuleDataControl" RangeSize="25"             id="TableSourceIterator"/> </executables> <bindings> <tree IterBinding="TableSourceIterator" id="GenericView"> <nodeDefinition Name="GenericViewNode"/> </tree> </bindings>  You'll notice three changes here.   Most importantly, you'll see that the hard-coded View Object name  that formally populated the iterator Binds attribute is gone and has been replaced by an expression (${pageFlowScope.voName}). This of course, is key, you can see that we can pass a parameter to the task flow, telling it exactly what VO to instantiate to populate this table! I've changed the IDs of the iterator and the tree binding, simply to reflect that they are now re-usable The tree binding itself has simplified and the node definition is now empty.  Now what this effectively means is that the #{node} map exposed through the tree binding will expose every attribute of the underlying iterator's collection - neat! (kudos to Eugene Fedorenko at this point who reminded me that this was even possible in his excellent "deep dive" session at OpenWorld  this year) Using the adaptive binding in the UI Now we have a parametrized  binding we have to make changes in the UI as well, first of all to reflect the new ID that we've assigned to the binding (of course) but also to change the column list from being a fixed known list to being a generic metadata driven set: <af:table value="#{bindings.GenericView.collectionModel}" rows="#{bindings.GenericView.rangeSize}"         fetchSize="#{bindings.GenericView.rangeSize}"           emptyText="#{bindings.GenericView.viewable ? 'No data to display.' : 'Access Denied.'}"           var="row" rowBandingInterval="0"           selectedRowKeys="#{bindings.GenericView.collectionModel.selectedRow}"           selectionListener="#{bindings.GenericView.collectionModel.makeCurrent}"           rowSelection="single" id="t1"> <af:forEach items="#{bindings.GenericView.attributeDefs}" var="def">   <af:column headerText="#{bindings.GenericView.labels[def.name]}" sortable="true"            sortProperty="#{def.name}" id="c1">     <af:outputText value="#{row[def.name]}" id="ot1"/>     </af:column>   </af:forEach> </af:table> Of course you are not constrained to a simple read only table here.  It's a normal tree binding and iterator that you are using behind the scenes so you can do all the usual things, but you can see the value of using ADFBC as the back end model as you have the rich pantheon of UI hints to use to derive things like labels (and validators and converters...)  One Final Twist  To finish on a high note I wanted to point out that you can take this even further and achieve the ultra-reusability I promised. Here's the new version of the pageDef iterator, see if you can notice the subtle change? <iterator Binds="{pageFlowScope.voName}"  DataControl="${pageFlowScope.dataControlName}" RangeSize="25"           id="TableSourceIterator"/>  Yes, as well as parametrizing the collection (VO) name, we can also parametrize the name of the data control. So your task flow can graduate from being re-usable within an application to being truly generic. So if you have some really common patterns within your app you can wrap them up and reuse then across multiple developments without having to dictate data control names, or connection names. This also demonstrates the importance of interacting with data only via the binding layer APIs. If you keep any code in the task flow generic in that way you can deal with data from multiple types of data controls, not just one flavour. Enjoy!

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• ADF Business Components

  - by Arda Eralp

  ADF Business Components and JDeveloper simplify the development, delivery, and customization of business applications for the Java EE platform. With ADF Business Components, developers aren't required to write the application infrastructure code required by the typical Java EE application to: Connect to the database Retrieve data Lock database records Manage transactions   ADF Business Components addresses these tasks through its library of reusable software components and through the supporting design time facilities in JDeveloper. Most importantly, developers save time using ADF Business Components since the JDeveloper design time makes typical development tasks entirely declarative. In particular, JDeveloper supports declarative development with ADF Business Components to: Author and test business logic in components which automatically integrate with databases Reuse business logic through multiple SQL-based views of data, supporting different application tasks Access and update the views from browser, desktop, mobile, and web service clients Customize application functionality in layers without requiring modification of the delivered application The goal of ADF Business Components is to make the business services developer more productive.   ADF Business Components provides a foundation of Java classes that allow your business-tier application components to leverage the functionality provided in the following areas: Simplifying Data Access Design a data model for client displays, including only necessary data Include master-detail hierarchies of any complexity as part of the data model Implement end-user Query-by-Example data filtering without code Automatically coordinate data model changes with business services layer Automatically validate and save any changes to the database   Enforcing Business Domain Validation and Business Logic Declaratively enforce required fields, primary key uniqueness, data precision-scale, and foreign key references Easily capture and enforce both simple and complex business rules, programmatically or declaratively, with multilevel validation support Navigate relationships between business domain objects and enforce constraints related to compound components   Supporting Sophisticated UIs with Multipage Units of Work Automatically reflect changes made by business service application logic in the user interface Retrieve reference information from related tables, and automatically maintain the information when the user changes foreign-key values Simplify multistep web-based business transactions with automatic web-tier state management Handle images, video, sound, and documents without having to use code Synchronize pending data changes across multiple views of data Consistently apply prompts, tooltips, format masks, and error messages in any application Define custom metadata for any business components to support metadata-driven user interface or application functionality Add dynamic attributes at runtime to simplify per-row state management   Implementing High-Performance Service-Oriented Architecture Support highly functional web service interfaces for business integration without writing code Enforce best-practice interface-based programming style Simplify application security with automatic JAAS integration and audit maintenance "Write once, run anywhere": use the same business service as plain Java class, EJB session bean, or web service   Streamlining Application Customization Extend component functionality after delivery without modifying source code Globally substitute delivered components with extended ones without modifying the application   ADF Business Components implements the business service through the following set of cooperating components: Entity object An entity object represents a row in a database table and simplifies modifying its data by handling all data manipulation language (DML) operations for you. These are basically your 1 to 1 representation of a database table. Each table in the database will have 1 and only 1 EO. The EO contains the mapping between columns and attributes. EO's also contain the business logic and validation. These are you core data services. They are responsible for updating, inserting and deleting records. The Attributes tab displays the actual mapping between attributes and columns, the mapping has following fields: Name : contains the name of the attribute we expose in our data model. Type : defines the data type of the attribute in our application. Column : specifies the column to which we want to map the attribute with Column Type : contains the type of the column in the database   View object A view object represents a SQL query. You use the full power of the familiar SQL language to join, filter, sort, and aggregate data into exactly the shape required by the end-user task. The attributes in the View Objects are actually coming from the Entity Object. In the end the VO will generate a query but you basically build a VO by selecting which EO need to participate in the VO and which attributes of those EO you want to use. That's why you have the Entity Usage column so you can see the relation between VO and EO. In the query tab you can clearly see the query that will be generated for the VO. At this stage we don't need it and just use it for information purpose. In later stages we might use it. Application module An application module is the controller of your data layer. It is responsible for keeping hold of the transaction. It exposes the data model to the view layer. You expose the VO's through the Application Module. This is the abstraction of your data layer which you want to show to the outside word.It defines an updatable data model and top-level procedures and functions (called service methods) related to a logical unit of work related to an end-user task. While the base components handle all the common cases through built-in behavior, customization is always possible and the default behavior provided by the base components can be easily overridden or augmented. When you create EO's, a foreign key will be translated into an association in our model. It defines the type of relation and who is the master and child as well as how the visibility of the association looks like. A similar concept exists to identify relations between view objects. These are called view links. These are almost identical as association except that a view link is based upon attributes defined in the view object. It can also be based upon an association. Here's a short summary: Entity Objects: representations of tables Association: Relations between EO's. Representations of foreign keys View Objects: Logical model View Links: Relationships between view objects Application Model: interface to your application  

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• What is Happening vs. What is Interesting

  - by Geertjan

  Devoxx 2011 was yet another confirmation that all development everywhere is either on the web or on mobile phones. Whether you looked at the conference schedule or attended sessions or talked to speakers at any point at all, it was very clear that no development whatsoever is done anymore on the desktop. In fact, that's something Tim Bray himself told me to my face at the speakers dinner. No new developments of any kind are happening on the desktop. Everyone who is currently on the desktop is working overtime to move all of their applications to the web. They're probably also creating a small subset of their application on an Android tablet, with an even smaller subset on their Android phone. Then you scratch that monolithic surface and find some interesting results. Without naming any names, I asked one of these prominent "ah, forget about the desktop" people at the Devoxx speakers dinner (and I have a witness): "Yes, the desktop is dead, but what about air traffic control, stock trading, oil analysis, risk management applications? In fact, what about any back office application that needs to be usable across all operating systems? Here there is no concern whatsoever with 100% accessibility which is, after all, the only thing that the web has over the desktop, (except when there's a network failure, of course, or when you find yourself in the 3/4 of the world where there's bandwidth problems)? There are 1000's of hidden applications out there that have processing requirements, security requirements, and the requirement that they'll be available even when the network is down or even completely unavailable. Isn't that a valid use case and aren't there 1000's of applications that fall into this so-called niche category? Are you not, in fact, confusing consumer applications, which are increasingly web-based and mobile-based, with high-end corporate applications, which typically need to do massive processing, of one kind or another, for which the web and mobile worlds are completely unsuited?" And you will not believe what the reply to the above question was. (Again, I have a witness to this discussion.) But here it is: "Yes. But those applications are not interesting. I do not want to spend any of my time or work in any way on those applications. They are boring." I'm sad to say that the leaders of the software development community, including those in the Java world, either share the above opinion or are led by it. Because they find something that is not new to be boring, they move on to what is interesting and start talking like the supposedly-boring developments don't even exist. (Kind of like a rapper pretending classical music doesn't exist.) Time and time again I find myself giving Java desktop development courses (at companies, i.e., not hobbyists, or students, but companies, i.e., the places where dollars are earned), where developers say to me: "The course you're giving about creating cross-platform, loosely coupled, and highly cohesive applications is really useful to us. Why do we never find information about this topic at conferences? Why can we never attend a session at a conference where the story about pluggable cross-platform Java is told? Why do we get the impression that we are uncool because we're not on the web and because we're not on a mobile phone, while the reason for that is because we're creating $1000,000 simulation software which has nothing to gain from being on the web or on the mobile phone?" And then I say: "Because nobody knows you exist. Because you're not submitting abstracts to conferences about your very interesting use cases. And because conferences tend to focus on what is new, which tends to be web related (especially HTML 5) or mobile related (especially Android). Because you're not taking the responsibility on yourself to tell the real stories about the real applications being developed all the time and every day. Because you yourself think your work is boring, while in fact it is fascinating. Because desktop developers are working from 9 to 5 on the desktop, in secure environments, such as banks and defense, where you can't spend time, nor have the interest in, blogging your latest tip or trick, as opposed to web developers, who tend to spend a lot of time on the web anyway and are therefore much more inclined to create buzz about the kind of work they're doing." So, next time you look at a conference program and wonder why there's no stories about large desktop development projects in the program, here's the short answer: "No one is going to put those items on the program until you start submitting those kinds of sessions. And until you start blogging. Until you start creating the buzz that the web developers have been creating around their work for the past 10 years or so. And, yes, indeed, programmers get the conference they deserve." And what about Tim Bray? Ask yourself, as Google's lead web technology evangelist, how many desktop developers do you think he talks to and, more generally, what his frame of reference is and what, clearly, he considers to be most interesting.

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• "Guiding" a Domain Expert to Retire from Programming

  - by James Kolpack

  I've got a friend who does IT at a local non-profit where they're using a custom web application which is no longer supported by the company who built it. (out of business, support was too expensive, I'm not sure...) Development on this app started around 10+ years ago so the technologies being harnessed are pretty out of date now - classic asp using vbscript and SQL Server 2000. The application domain is in the realm of government bookkeeping - so even though the development team is long gone, there are often new requirements of this software. Enter the... The domain expert. This is an middle aged accounting whiz without much (or any?) prior development experience. He studied the pages, code and queries and learned how to ape the style of the original team which, believe me, is mediocre at best. He's very clever and very tenacious but has no experience in software beyond what he's picked up from this app. Otherwise, he's a pleasant guy to talk to and definitely knows his domain. My friend in IT, and probably his superiors in the company, want him out of the code. They view him as wasting his expertise on coding tasks he shouldn't be doing. My friend got me involved with a few small contracts which I handled without much problem - other than somewhat of a communication barrier with the domain expert. He explained the requirements very quickly, assuming prior knowledge of the domain which I do not have. This is partially his normal style, and I think maybe a bit of resentment from my involvement. So, I think he feels like the owner of the code and has entrenched himself in a development position. So... his coding technique. One of his latest endeavors was to make a page that only he could reach (theoretically - the security model for the system is wretched) where he can enter a raw SQL query, run it, and save the query to run again later. A report that I worked on had been originally implemented by him using 6 distinct queries, 3 or 4 temp tables to coordinate the data between the queries, and the final result obtained by importing the data from the final query into Access and doing a pivot and some formatting. It worked - well, some of the results were incorrect - but at what a cost! (I implemented the report in a single query with at least 1/10th the amount of code.) He edits code in notepad. He doesn't seem to know about online reference material for the languages. I recently read an article on Dr. Dobbs titled "What Makes Bad Programmers Different" - and instantly thought of our domain expert. From the article: Their code is large, messy, and bug laden. They have very superficial knowledge of their problem domain and their tools. Their code has a lot of copy/paste and they have very little interest in techniques that reduce it. The fail to account for edge cases, while inefficiently dealing with the general case. They never have time to comment their code or break it into smaller pieces. Empirical evidence plays no little role in their decisions. 5.5 out of 6. My friend is wanting me to argue the case to their management - specifically, I got this email from their manager to respond to: ...Also, I need to talk to you about what effect there is from Domain Expert continuing to make edits to the live environment. If that is a problem for you I need to know so I can have his access blocked. Some examples would help. In my opinion, from a technical standpoint, it's dangerous to have him making changes without any oversight. On the other hand, I'm just doing one-off contracts at this point and don't have much desire to get involved deeply enough that I'm essentially arguing as one of the Bobs from Office Space. I'd like to help my friend out - but I feel like I'm getting in the middle of a political battle. More importantly - if I do get involved and suggest that his editing privileges be removed, it needs to be handled carefully so that doesn't feel belittled. He is beyond a doubt the foremost expert on this system. I'm hoping this is familiar territory for some other stackechangers, because I'm feeling a little bewildered. How should I respond? Should I argue that he shouldn't be allowed to touch the code? Should I phrase it as "no single developer, no matter how experienced, should be working on production code unchecked"? Should I argue to keep him involved with the code, but with a review process? Should I say "glad I could help, but uh, I'm busy now!" Other options? Thanks a bunch!

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• Extending Expression Blend 4 &amp; Blend for Visual Studio 2012

  - by Chris Skardon

  Just getting this off the bat, I presume this will also work for Blend 5, but I can’t confirm it… Anyhews, I imagine you’re here because you want to know how to create an addin for Blend, so let’s jump right in there! First, and foremost, we’re going to need to ensure our development environment has the right setup, so the checklist: Visual Studio 2012 Blend for Visual Studio 2012 OK, let’s create a new project (class library, .NET 4.5): Hello.Extension The ‘.Extension’ bit is very very important. The addin will not work unless it is named in this way. You can put whatever you want at the front, but it has to have the extension bit. OK, so now we have a solution with one project. To this project we need to add references to the following things: Microsoft.Expression.Extensibility (from c:\program files\Microsoft Visual Studio 11.0\Blend\   -- x86 folder if you are on an x64 windows install) Microsoft.Expression.Framework (same location as above) PresentationCore PresentationFramework WindowsBase System.ComponentModel.Composition Got them? ACE. Let’s now add a project to contain our control, so, create a new WPF Application project, cunningly named something like ‘Hello.Control’… (I’m creating a WPF application here, because I’m too lazy to dig up the correct references, and this will add all the ones I need ) Once that is created, delete the App.xaml and MainWindow.xaml files, we won’t be needing them. You will also need to change the properties of the project itself, so it is only a class library. Once that is done, let’s add a new UserControl, which will be this: <UserControl x:Class="Hello.Control.HelloControl" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="300"> <Grid> <TextBlock Text="HELLO!!!"/> </Grid> </UserControl> Impressive eh? Now, let’s reference the WPF project from the Extension library. All that’s left now is to code up our extension… So, add a class to the Extension project (name wise doesn’t matter), and make it implement the IPackage interface from the Microsoft.Expression.Extensibility library: public class HelloExtension : IPackage { /**/ } We’ll implement the two methods we need to: public class HelloExtension : IPackage { public void Load(IServices services) { } public void Unload() { } } We’re only really concerned about the Load method in this case, as let’s face it, the extension we have doesn’t need to do a lot to bog off. The interesting thing about the Load method is that it receives an IServices instance. This allows us to get access to all the services that Expression provides, in this case we’re interested in one in particular, the ‘IWindowService’ So, let’s get that bad boy… private IWindowService _windowService; public void Load(IServices services) { _windowService = services.GetService<IWindowService>(); } Nailed it… But why? The WindowService allows us to register our UserControl with Blend, which in turn allows people to activate and see it, which is a big plus point. So, let’s do that… We’ll create an ‘Initialize’ method to create our new control, and add it to the WindowService: private HelloControl _helloControl; public void Initialize() { _helloControl = new HelloControl(); if (_windowService.PaletteRegistry["HelloPanel"] == null) _windowService.RegisterPalette("HelloPanel", _helloControl, "Hello Window"); } First we check that we’re not already registered, and if we’re not we register, the first argument is the identifier used by the service to, well, identify your extension. The second argument is the actual control, the third argument is the name that people will see in the ‘Windows’ menu of Blend itself (so important note here – don’t put anything embarrassing or (need I say it?) sweary…) There are only two things to do now - Call ‘Initialize()’ from our Load method, and Export the class This is easy money – add [Export(typeof(IPackage))] to the top of our class… The full code will (should) look like this: [Export(typeof (IPackage))] public class HelloExtension : IPackage { private HelloControl _helloControl; private IWindowService _windowService; public void Load(IServices services) { _windowService = services.GetService<IWindowService>(); Initialize(); } public void Unload() { } public void Initialize() { _helloControl = new HelloControl(); if (_windowService.PaletteRegistry["HelloControl"] == null) _windowService.RegisterPalette("HelloControl", _helloControl, "Hello Window"); } } If you build this and copy it to your ‘Extensions’ folder in Blend (c:\program files\microsoft visual studio 11.0\blend\) and start Blend, you should see ‘Hello Window’ listed in the Window menu: That as they say is it!

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• Context is Everything

  - by Angus Graham

  Normal 0 false false false EN-CA X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Context is Everything How many times have you have you asked a question only to hear an answer like “Well, it depends. What exactly are you trying to do?”.  There are times that raw information can’t tell us what we need to know without putting it in a larger context. Let's take a real world example.  If I'm a maintenance planner trying to figure out which assets should be replaced during my next maintenance window, I'm going to go to my Asset Management System.  I can get it to spit out a list of assets that have failed several times over the last year.  But what are these assets connected to?  Is there any safety consequences to shutting off this pipeline to do the work?  Is some other work that's planned going to conflict with replacing this asset?  Several of these questions can't be answered by simply spitting out a list of asset IDs.  The maintenance planner will have to reference a diagram of the plant to answer several of these questions. This is precisely the idea behind Augmented Business Visualization. An Augmented Business Visualization (ABV) solution is one where your structured data (enterprise application data) and your unstructured data (documents, contracts, floor plans, designs, etc.) come together to allow you to make better decisions.  Essentially we're showing your business data into its context. AutoVue allows you to create ABV solutions by integrating your enterprise application with AutoVue’s hotspot framework. Hotspots can be defined for your document. Users can click these hotspots to trigger actions in your enterprise app. Similarly, the enterprise app can highlight the hotspots in your document based on its business data, creating a visual dashboard of your business data in the context of your document. ABV is not new. We introduced the hotspot framework in AutoVue 20.1 with text hotspots. Any text in a PDF or 2D CAD drawing could be turned into a hotspot. In 20.2 we have enhanced this to include 2 new types of hotspots: 3D and regional hotspots. 3D hotspots allow you to turn 3D parts into hotspots. Hotspots can be defined based on the attributes of the part, so you can create hotspots based on part numbers, material, date of delivery, etc.  Regional hotspots allow an administrator to define rectangular regions on any PDF, image, or 2D CAD drawing. This is perfect for cases where the document you’re using either doesn’t have text in it (a JPG or TIFF for example) or if you want to define hotspots that don’t correspond to the text in the document. There are lots of possible uses for AutoVue hotspots.  A great demonstration of how our hotspot capabilities can help add context to enterprise data in the Energy sector can be found in the following AutoVue movies: Maintenance Planning in the Energy Sector - Watch it Now Capital Construction Project Management in the Energy Sector  -  Watch it Now Commissioning and Handover Process for the Energy Sector  -  Watch it Now

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• iOS Support with Windows Azure Mobile Services – now with Push Notifications

  - by ScottGu

  A few weeks ago I posted about a number of improvements to Windows Azure Mobile Services. One of these was the addition of an Objective-C client SDK that allows iOS developers to easily use Mobile Services for data and authentication.  Today I'm excited to announce a number of improvement to our iOS SDK and, most significantly, our new support for Push Notifications via APNS (Apple Push Notification Services).  This makes it incredibly easy to fire push notifications to your iOS users from Windows Azure Mobile Service scripts. Push Notifications via APNS We've provided two complete tutorials that take you step-by-step through the provisioning and setup process to enable your Windows Azure Mobile Service application with APNS (Apple Push Notification Services), including all of the steps required to configure your application for push in the Apple iOS provisioning portal: Getting started with Push Notifications - iOS Push notifications to users by using Mobile Services - iOS Once you've configured your application in the Apple iOS provisioning portal and uploaded the APNS push certificate to the Apple provisioning portal, it's just a matter of uploading your APNS push certificate to Mobile Services using the Windows Azure admin portal: Clicking the “upload” within the “Push” tab of your Mobile Service allows you to browse your local file-system and locate/upload your exported certificate.  As part of this you can also select whether you want to use the sandbox (dev) or production (prod) Apple service: Now, the code to send a push notification to your clients from within a Windows Azure Mobile Service is as easy as the code below: push.apns.send(deviceToken, {      alert: 'Toast: A new Mobile Services task.',      sound: 'default' }); This will cause Windows Azure Mobile Services to connect to APNS (Apple Push Notification Service) and send a notification to the iOS device you specified via the deviceToken: Check out our reference documentation for full details on how to use the new Windows Azure Mobile Services apns object to send your push notifications. Feedback Scripts An important part of working with any PNS (Push Notification Service) is handling feedback for expired device tokens and channels. This typically happens when your application is uninstalled from a particular device and can no longer receive your notifications. With Windows Notification Services you get an instant response from the HTTP server.  Apple’s Notification Services works in a slightly different way and provides an additional endpoint you can connect to poll for a list of expired tokens. As with all of the capabilities we integrate with Mobile Services, our goal is to allow developers to focus more on building their app and less on building infrastructure to support their ideas. Therefore we knew we had to provide a simple way for developers to integrate feedback from APNS on a regular basis.  This week’s update now includes a new screen in the portal that allows you to optionally provide a script to process your APNS feedback – and it will be executed by Mobile Services on an ongoing basis: This script is invoked periodically while your service is active. To poll the feedback endpoint you can simply call the apns object's getFeedback method from within this script: push.apns.getFeedback({       success: function(results) {           // results is an array of objects with a deviceToken and time properties      } }); This returns you a list of invalid tokens that can now be removed from your database. iOS Client SDK improvements Over the last month we've continued to work with a number of iOS advisors to make improvements to our Objective-C SDK. The SDK is being developed under an open source license (Apache 2.0) and is available on github. Many of the improvements are behind the scenes to improve performance and memory usage. However, one of the biggest improvements to our iOS Client API is the addition of an even easier login method.  Below is the Objective-C code you can now write to invoke it: [client loginWithProvider:@"twitter"                     onController:self                        animated:YES                      completion:^(MSUser *user, NSError *error) {      // if no error, you are now logged in via twitter }]; This code will automatically present and dismiss our login view controller as a modal dialog on the specified controller.  This does all the hard work for you and makes login via Twitter, Google, Facebook and Microsoft Account identities just a single line of code. My colleague Josh just posted a short video demonstrating these new features which I'd recommend checking out: Summary The above features are all now live in production and are available to use immediately.  If you don’t already have a Windows Azure account, you can sign-up for a free trial and start using Mobile Services today. Visit the Windows Azure Mobile Developer Center to learn more about how to build apps with Mobile Services. Hope this helps, Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

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• Pirates, Treasure Chests and Architectural Mapping

  Pirate 1: Why do pirates create treasure maps? Pirate 2: I do not know.Pirate 1: So they can find their gold. Yes, that was a bad joke, but it does illustrate a point. Pirates are known for drawing treasure maps to their most prized possession. These documents detail the decisions pirates made in order to hide and find their chests of gold. The map allows them to trace the steps they took originally to hide their treasure so that they may return. As software engineers, programmers, and architects we need to treat software implementations much like our treasure chest. Why is software like a treasure chest? It cost money, time,  and resources to develop (Usually) It can make or save money, time, and resources (Hopefully) If we operate under the assumption that software is like a treasure chest then wouldn’t make sense to document the steps, rationale, concerns, and decisions about how it was designed? Pirates are notorious for documenting where they hide their treasure.  Shouldn’t we as creators of software do the same? By documenting our design decisions and rationale behind them will help others be able to understand and maintain implemented systems. This can only be done if the design decisions are correctly mapped to its corresponding implementation. This allows for architectural decisions to be traced from the conceptual model, architectural design and finally to the implementation. Mapping gives software professional a method to trace the reason why specific areas of code were developed verses other options. Just like the pirates we need to able to trace our steps from the start of a project to its implementation,  so that we will understand why specific choices were chosen. The traceability of a software implementation that actually maps back to its originating design decisions is invaluable for ensuring that architectural drifting and erosion does not take place. The drifting and erosion is prevented by allowing others to understand the rational of why an implementation was created in a specific manor or methodology The process of mapping distinct design concerns/decisions to the location of its implemented is called traceability. In this context traceability is defined as method for connecting distinctive software artifacts. This process allows architectural design models and decisions to be directly connected with its physical implementation. The process of mapping architectural design concerns to a software implementation can be very complex. However, most design decision can be placed in  a few generalized categories. Commonly Mapped Design Decisions Design Rationale Components and Connectors Interfaces Behaviors/Properties Design rational is one of the hardest categories to map directly to an implementation. Typically this rational is mapped or document in code via comments. These comments consist of general design decisions and reasoning because they do not directly refer to a specific part of an application. They typically focus more on the higher level concerns. Components and connectors can directly be mapped to architectural concerns. Typically concerns subdivide an application in to distinct functional areas. These functional areas then can map directly back to their originating concerns.Interfaces can be mapped back to design concerns in one of two ways. Interfaces that pertain to specific function definitions can be directly mapped back to its originating concern(s). However, more complicated interfaces require additional analysis to ensure that the proper mappings are created. Depending on the complexity some Behaviors\Properties can be translated directly into a generic implementation structure that is ready for business logic. In addition, some behaviors can be translated directly in to an actual implementation depending on the complexity and architectural tools used. Mapping design concerns to an implementation is a lot of work to maintain, but is doable. In order to ensure that concerns are mapped correctly and that an implementation correctly reflects its design concerns then one of two standard approaches are usually used. All Changes Come From ArchitectureBy forcing all application changes to come through the architectural model prior to implementation then the existing mappings will be used to locate where in the implementation changes need to occur. Allow Changes From Implementation Or Architecture By allowing changes to come from the implementation and/or the architecture then the other area must be kept in sync. This methodology is more complex compared to the previous approach.  One reason to justify the added complexity for an application is due to the fact that this approach tends to detect and prevent architectural drift and erosion. Additionally, this approach is usually maintained via software because of the complexity. Reference:Taylor, R. N., Medvidovic, N., & Dashofy, E. M. (2009). Software architecture: Foundations, theory, and practice Hoboken, NJ: John Wiley & Sons  

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• Navigation in a #WP7 application with MVVM Light

  - by Laurent Bugnion

  In MVVM applications, it can be a bit of a challenge to send instructions to the view (for example a page) from a viewmodel. Thankfully, we have good tools at our disposal to help with that. In his excellent series “MVVM Light Toolkit soup to nuts”, Jesse Liberty proposes one approach using the MVVM Light messaging infrastructure. While this works fine, I would like to show here another approach using what I call a “view service”, i.e. an abstracted service that is invoked from the viewmodel, and implemented on the view. Multiple kinds of view services In fact, I use view services quite often, and even started standardizing them for the Windows Phone 7 applications I work on. If there is interest, I will be happy to show other such view services, for example Animation services, responsible to start/stop animations on the view. Dialog service, in charge of displaying messages to the user and gathering feedback. Navigation service, in charge of navigating to a given page directly from the viewmodel. In this article, I will concentrate on the navigation service. The INavigationService interface In most WP7 apps, the navigation service is used in quite a straightforward way. We want to: Navigate to a given URI. Go back. Be notified when a navigation is taking place, and be able to cancel. The INavigationService interface is quite simple indeed: public interface INavigationService { event NavigatingCancelEventHandler Navigating; void NavigateTo(Uri pageUri); void GoBack(); } Obviously, this interface can be extended if necessary, but in most of the apps I worked on, I found that this covers my needs. The NavigationService class It is possible to nicely pack the navigation service into its own class. To do this, we need to remember that all the PhoneApplicationPage instances use the same instance of the navigation service, exposed through their NavigationService property. In fact, in a WP7 application, it is the main frame (RootFrame, of type PhoneApplicationFrame) that is responsible for this task. So, our implementation of the NavigationService class can leverage this. First the class will grab the PhoneApplicationFrame and store a reference to it. Also, it registers a handler for the Navigating event, and forwards the event to the listening viewmodels (if any). Then, the NavigateTo and the GoBack methods are implemented. They are quite simple, because they are in fact just a gateway to the PhoneApplicationFrame. The whole class is as follows: public class NavigationService : INavigationService { private PhoneApplicationFrame _mainFrame; public event NavigatingCancelEventHandler Navigating; public void NavigateTo(Uri pageUri) { if (EnsureMainFrame()) { _mainFrame.Navigate(pageUri); } } public void GoBack() { if (EnsureMainFrame() && _mainFrame.CanGoBack) { _mainFrame.GoBack(); } } private bool EnsureMainFrame() { if (_mainFrame != null) { return true; } _mainFrame = Application.Current.RootVisual as PhoneApplicationFrame; if (_mainFrame != null) { // Could be null if the app runs inside a design tool _mainFrame.Navigating += (s, e) => { if (Navigating != null) { Navigating(s, e); } }; return true; } return false; } } Exposing URIs I find that it is a good practice to expose each page’s URI as a constant. In MVVM Light applications, a good place to do that is the ViewModelLocator, which already acts like a central point of setup for the views and their viewmodels. Note that in some cases, it is necessary to expose the URL as a string, for instance when a query string needs to be passed to the view. So for example we could have: public static readonly Uri MainPageUri = new Uri("/MainPage.xaml", UriKind.Relative); public const string AnotherPageUrl = "/AnotherPage.xaml?param1={0}&param2={1}"; Creating and using the NavigationService Normally, we only need one instance of the NavigationService class. In cases where you use an IOC container, it is easy to simply register a singleton instance. For example, I am using a modified version of a super simple IOC container, and so I can register the navigation service as follows: SimpleIoc.Register<INavigationService, NavigationService>(); Then, it can be resolved where needed with: SimpleIoc.Resolve<INavigationService>(); Or (more frequently), I simply declare a parameter on the viewmodel constructor of type INavigationService and let the IOC container do its magic and inject the instance of the NavigationService when the viewmodel is created. On supported platforms (for example Silverlight 4), it is also possible to use MEF. Or, of course, we can simply instantiate the NavigationService in the ViewModelLocator, and pass this instance as a parameter of the viewmodels’ constructor, injected as a property, etc… Once the instance has been passed to the viewmodel, it can be used, for example with: NavigationService.NavigateTo(ViewModelLocator.ComparisonPageUri); Testing Thanks to the INavigationService interface, navigation can be mocked and tested when the viewmodel is put under unit test. Simply implement and inject a mock class, and assert that the methods are called as they should by the viewmodel. Conclusion As usual, there are multiple ways to code a solution answering your needs. I find that view services are a really neat way to delegate view-specific responsibilities such as animation, dialogs and of course navigation to other classes through an abstracted interface. In some cases, such as the NavigationService class exposed here, it is even possible to standardize the implementation and pack it in a class library for reuse. I hope that this sample is useful! Happy coding. Laurent   Laurent Bugnion (GalaSoft) Subscribe | Twitter | Facebook | Flickr | LinkedIn

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• Inside Red Gate - Be Reasonable!

  - by simonc

  As I discussed in my previous posts, divisions and project teams within Red Gate are allowed a lot of autonomy to manage themselves. It's not just the teams though, there's an awful lot of freedom given to individual employees within the company as well. Reasonableness How Red Gate treats it's employees is embodied in the phrase 'You will be reasonable with us, and we will be reasonable with you'. As an employee, you are trusted to do your job to the best of you ability. There's no one looking over your shoulder, no one clocking you in and out each day. Everyone is working at the company because they want to, and one of the core ideas of Red Gate is that the company exists to 'let people do the best work of their lives'. Everything is geared towards that. To help you do your job, office services and the IT department are there. If you need something to help you work better (a third or fourth monitor, footrests, or a new keyboard) then ask people in Information Systems (IS) or Office Services and you will be given it, no questions asked. Everyone has administrator access to their own machines, and you can install whatever you want on it. If there's a particular bit of software you need, then ask IS and they will buy it. As an example, last year I wanted to replace my main hard drive with an SSD; I had a summer job at school working in a computer repair shop, so knew what to do. I went to IS and asked for 'an SSD, a SATA cable, and a screwdriver'. And I got it there and then, even the screwdriver. Awesome. I screwed it in myself, copied all my main drive files across, and I was good to go. Of course, if you're not happy doing that yourself, then IS will sort it all out for you, no problems. If you need something that the company doesn't have (say, a book off Amazon, or you need some specifications printing off & bound), then everyone has a expense limit of £100 that you can use without any sign-off needed from your managers. If you need a company credit card for whatever reason, then you can get it. This freedom extends to working hours and holiday; you're expected to be in the office 11am-3pm each day, but outside those times you can work whenever you want. If you need a half-day holiday on a days notice, or even the same day, then you'll get it, unless there's a good reason you're needed that day. If you need to work from home for a day or so for whatever reason, then you can. If it's reasonable, then it's allowed. Trust issues? A lot of trust, and a lot of leeway, is given to all the people in Red Gate. Everyone is expected to work hard, do their jobs to the best of their ability, and there will be a minimum of bureaucratic obstacles that stop you doing your work. What happens if you abuse this trust? Well, an example is company trip expenses. You're free to expense what you like; food, drink, transport, etc, but if you expenses are not reasonable, then you will never travel with the company again. Simple as that. Everyone knows when they're abusing the system, so simply don't do it. Along with reasonableness, another phrase used is 'Don't be an a**hole'. If you act like an a**hole, and abuse any of the trust placed in you, even if you're the best tester, salesperson, dev, or manager in the company, then you won't be a part of the company any more. From what I know about other companies, employee trust is highly variable between companies, all the way up to CCTV trained on employee's monitors. As a dev, I want to produce well-written & useful code that solves people's problems. Being able to get whatever I need - install whatever tools I need, get time off when I need to, obtain reference books within a day - all let me do my job, and so let Red Gate help other people do their own jobs through the tools we produce. Plus, I don't think I would like working for a company that doesn't allow admin access to your own machine and blocks Facebook! Cross posted from Simple Talk.

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• The sign of a true manager is delegation (C# style)

  - by MarkPearl

  Today I thought I would write a bit about delegates in C#. Up till recently I have managed to side step any real understanding of what delegates do and why they are useful – I mean, I know roughly what they do and have used them a lot, but I have never really got down dirty with them and mucked about. Recently however with my renewed interest in Silverlight delegates came up again as a possible solution to a particular problem, and suddenly I found myself opening a bland little console application to just see exactly how far I could take delegates with my limited knowledge. So, let’s first look at the MSDN definition of delegates… A delegate declaration defines a reference type that can be used to encapsulate a method with a specific signature. A delegate instance encapsulates a static or an instance method. Delegates are roughly similar to function pointers in C++; however, delegates are type-safe and secure. Well, don’t you love MSDN for such a useful definition. I must give it credit though… later on it really explains it a bit better by saying “A delegate lets you pass a function as a parameter. The type safety of delegates requires the function you pass as a delegate to have the same signature as the delegate declaration.” A little more reading up on delegates mentions that delegates are similar to interfaces in that they enable the separation of specification and implementation. A delegate declares a single method, while an interface declares a group of methods. So enough reading - lets look at some code and see a basic example of a delegate… Let’s assume we have a console application with a simple delegate declared called AdjustValue like below… class Program { private delegate int AdjustValue(int val); static void Main(string[] args) { } } In a sense, all we have said is that we will be creating one or more methods that follow the same pattern as AdjustValue – i.e. they will take one input value of type int and return an integer. We could then expand our code to have various methods that match the structure of our delegate AdjustValue (remember the structure is int xxx (int xxx)) class Program { private delegate int AdjustValue(int val); private static int Dbl(int val) { return val * 2; } private static int AlwaysOne(int val) { return 1; } static void Main(string[] args) { } }  Above I have expanded my project to have two methods, one called Dbl and the other AlwaysOne. Dbl always returns double the input val and AlwaysOne always returns 1. I could now declare a variable and assign it to be one of those functions, like the following… class Program { private delegate int AdjustValue(int val); private static int Dbl(int val) { return val * 2; } private static int AlwaysOne(int val) { return 1; } static void Main(string[] args) { AdjustValue myDelegate; myDelegate = Dbl; Console.WriteLine(myDelegate(1).ToString()); Console.ReadLine(); } } In this instance I have declared an instance of the AdjustValue delegate called myDelegate; I have then told myDelegate to point to the method Dbl, and then called myDelegate(1). What would the result be? Yes, in this instance it would be exactly the same as me calling the following code… static void Main(string[] args) { Console.WriteLine(Dbl(1).ToString()); Console.ReadLine(); }   So why all the extra work for delegates when we could just do what we did above and call the method directly? Well… that separation of specification to implementation comes to mind. So, this all seems pretty simple. Let’s take a slightly more complicated variation to the console application. Assume that my project is the same as the one previously except that my main method is adjusted as follows… static void Main(string[] args) { AdjustValue myDelegate; myDelegate = Dbl; myDelegate = AlwaysOne; Console.WriteLine(myDelegate(1).ToString()); Console.ReadLine(); } What would happen in this scenario? Quite simply “1” would be written to the console, the reason being that myDelegate was last pointing to the AlwaysOne method before it was called. Make sense? In a way, the myDelegate is a variable method that can be swapped and changed when needed. Let’s make the code a little more confusing by using a delegate in the declaration of another delegate as shown below… class Program { private delegate int AdjustValue(InputValue val); private delegate int InputValue(); private static int Dbl(InputValue val) { return val()*2; } private static int GetInputVal() { Console.WriteLine("Enter a whole number : "); return Convert.ToInt32(Console.ReadLine()); } static void Main(string[] args) { AdjustValue myDelegate; myDelegate = Dbl; Console.WriteLine(myDelegate(GetInputVal).ToString()); Console.ReadLine(); } }   Now it gets really interesting because it looks like we have passed a method into a function in the main method by declaring… Console.WriteLine(myDelegate(GetInputVal).ToString()); So, what it the output? Well, try take a guess on what will happen – then copy the code and see if you got it right. Well that brings me to the end of this short explanation of Delegates. Hopefully it made sense!

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• Collaborative Whiteboard using WebSocket in GlassFish 4 - Text/JSON and Binary/ArrayBuffer Data Transfer (TOTD #189)

  - by arungupta

  This blog has published a few blogs on using JSR 356 Reference Implementation (Tyrus) as its integrated in GlassFish 4 promoted builds. TOTD #183: Getting Started with WebSocket in GlassFish TOTD #184: Logging WebSocket Frames using Chrome Developer Tools, Net-internals and Wireshark TOTD #185: Processing Text and Binary (Blob, ArrayBuffer, ArrayBufferView) Payload in WebSocket TOTD #186: Custom Text and Binary Payloads using WebSocket One of the typical usecase for WebSocket is online collaborative games. This Tip Of The Day (TOTD) explains a sample that can be used to build such games easily. The application is a collaborative whiteboard where different shapes can be drawn in multiple colors. The shapes drawn on one browser are automatically drawn on all other peer browsers that are connected to the same endpoint. The shape, color, and coordinates of the image are transfered using a JSON structure. A browser may opt-out of sharing the figures. Alternatively any browser can send a snapshot of their existing whiteboard to all other browsers. Take a look at this video to understand how the application work and the underlying code. The complete sample code can be downloaded here. The code behind the application is also explained below. The web page (index.jsp) has a HTML5 Canvas as shown: <canvas id="myCanvas" width="150" height="150" style="border:1px solid #000000;"></canvas> And some radio buttons to choose the color and shape. By default, the shape, color, and coordinates of any figure drawn on the canvas are put in a JSON structure and sent as a message to the WebSocket endpoint. The JSON structure looks like: { "shape": "square", "color": "#FF0000", "coords": { "x": 31.59999942779541, "y": 49.91999053955078 }} The endpoint definition looks like: @WebSocketEndpoint(value = "websocket",encoders = {FigureDecoderEncoder.class},decoders = {FigureDecoderEncoder.class})public class Whiteboard { As you can see, the endpoint has decoder and encoder registered that decodes JSON to a Figure (a POJO class) and vice versa respectively. The decode method looks like: public Figure decode(String string) throws DecodeException { try { JSONObject jsonObject = new JSONObject(string); return new Figure(jsonObject); } catch (JSONException ex) { throw new DecodeException("Error parsing JSON", ex.getMessage(), ex.fillInStackTrace()); }} And the encode method looks like: public String encode(Figure figure) throws EncodeException { return figure.getJson().toString();} FigureDecoderEncoder implements both decoder and encoder functionality but thats purely for convenience. But the recommended design pattern is to keep them in separate classes. In certain cases, you may even need only one of them. On the client-side, the Canvas is initialized as: var canvas = document.getElementById("myCanvas");var context = canvas.getContext("2d");canvas.addEventListener("click", defineImage, false); The defineImage method constructs the JSON structure as shown above and sends it to the endpoint using websocket.send(). An instant snapshot of the canvas is sent using binary transfer with WebSocket. The WebSocket is initialized as: var wsUri = "ws://localhost:8080/whiteboard/websocket";var websocket = new WebSocket(wsUri);websocket.binaryType = "arraybuffer"; The important part is to set the binaryType property of WebSocket to arraybuffer. This ensures that any binary transfers using WebSocket are done using ArrayBuffer as the default type seem to be blob. The actual binary data transfer is done using the following: var image = context.getImageData(0, 0, canvas.width, canvas.height);var buffer = new ArrayBuffer(image.data.length);var bytes = new Uint8Array(buffer);for (var i=0; i<bytes.length; i++) { bytes[i] = image.data[i];}websocket.send(bytes); This comprehensive sample shows the following features of JSR 356 API: Annotation-driven endpoints Send/receive text and binary payload in WebSocket Encoders/decoders for custom text payload In addition, it also shows how images can be captured and drawn using HTML5 Canvas in a JSP. How could this be turned in to an online game ? Imagine drawing a Tic-tac-toe board on the canvas with two players playing and others watching. Then you can build access rights and controls within the application itself. Instead of sending a snapshot of the canvas on demand, a new peer joining the game could be automatically transferred the current state as well. Do you want to build this game ? I built a similar game a few years ago. Do somebody want to rewrite the game using WebSocket APIs ? :-) Many thanks to Jitu and Akshay for helping through the WebSocket internals! Here are some references for you: JSR 356: Java API for WebSocket - Specification (Early Draft) and Implementation (already integrated in GlassFish 4 promoted builds) Subsequent blogs will discuss the following topics (not necessary in that order) ... Error handling Interface-driven WebSocket endpoint Java client API Client and Server configuration Security Subprotocols Extensions Other topics from the API

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• How to move a rectangle properly?

  - by bodycountPP

  I recently started to learn OpenGL. Right now I finished the first chapter of the "OpenGL SuperBible". There were two examples. The first had the complete code and showed how to draw a simple triangle. The second example is supposed to show how to move a rectangle using SpecialKeys. The only code provided for this example was the SpecialKeys method. I still tried to implement it but I had two problems. In the previous example I declared and instaciated vVerts in the SetupRC() method. Now as it is also used in the SpecialKeys() method, I moved the declaration and instantiation to the top of the code. Is this proper c++ practice? I copied the part where vertex positions are recalculated from the book, but I had to pick the vertices for the rectangle on my own. So now every time I press a key for the first time the rectangle's upper left vertex is moved to (-0,5:-0.5). This ok because of GLfloat blockX = vVerts[0]; //Upper left X GLfloat blockY = vVerts[7]; // Upper left Y But I also think that this is the reason why my rectangle is shifted in the beginning. After the first time a key was pressed everything works just fine. Here is my complete code I hope you can help me on those two points. GLBatch squareBatch; GLShaderManager shaderManager; //Load up a triangle GLfloat vVerts[] = {-0.5f,0.5f,0.0f, 0.5f,0.5f,0.0f, 0.5f,-0.5f,0.0f, -0.5f,-0.5f,0.0f}; //Window has changed size, or has just been created. //We need to use the window dimensions to set the viewport and the projection matrix. void ChangeSize(int w, int h) { glViewport(0,0,w,h); } //Called to draw the scene. void RenderScene(void) { //Clear the window with the current clearing color glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT|GL_STENCIL_BUFFER_BIT); GLfloat vRed[] = {1.0f,0.0f,0.0f,1.0f}; shaderManager.UseStockShader(GLT_SHADER_IDENTITY,vRed); squareBatch.Draw(); //perform the buffer swap to display the back buffer glutSwapBuffers(); } //This function does any needed initialization on the rendering context. //This is the first opportunity to do any OpenGL related Tasks. void SetupRC() { //Blue Background glClearColor(0.0f,0.0f,1.0f,1.0f); shaderManager.InitializeStockShaders(); squareBatch.Begin(GL_QUADS,4); squareBatch.CopyVertexData3f(vVerts); squareBatch.End(); } //Respond to arrow keys by moving the camera frame of reference void SpecialKeys(int key,int x,int y) { GLfloat stepSize = 0.025f; GLfloat blockSize = 0.5f; GLfloat blockX = vVerts[0]; //Upper left X GLfloat blockY = vVerts[7]; // Upper left Y if(key == GLUT_KEY_UP) { blockY += stepSize; } if(key == GLUT_KEY_DOWN){blockY -= stepSize;} if(key == GLUT_KEY_LEFT){blockX -= stepSize;} if(key == GLUT_KEY_RIGHT){blockX += stepSize;} //Recalculate vertex positions vVerts[0] = blockX; vVerts[1] = blockY - blockSize*2; vVerts[3] = blockX + blockSize * 2; vVerts[4] = blockY - blockSize *2; vVerts[6] = blockX+blockSize*2; vVerts[7] = blockY; vVerts[9] = blockX; vVerts[10] = blockY; squareBatch.CopyVertexData3f(vVerts); glutPostRedisplay(); } //Main entry point for GLUT based programs int main(int argc, char** argv) { //Sets the working directory. Not really needed gltSetWorkingDirectory(argv[0]); //Passes along the command-line parameters and initializes the GLUT library. glutInit(&argc,argv); //Tells the GLUT library what type of display mode to use, when creating the window. //Double buffered window, RGBA-Color mode,depth-buffer as part of our display, stencil buffer also available glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGBA|GLUT_DEPTH|GLUT_STENCIL); //Window size glutInitWindowSize(800,600); glutCreateWindow("MoveRect"); glutReshapeFunc(ChangeSize); glutDisplayFunc(RenderScene); glutSpecialFunc(SpecialKeys); //initialize GLEW library GLenum err = glewInit(); //Check that nothing goes wrong with the driver initialization before we try and do any rendering. if(GLEW_OK != err) { fprintf(stderr,"Glew Error: %s\n",glewGetErrorString); return 1; } SetupRC(); glutMainLoop(); return 0; }

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• What's New in Oracle VM VirtualBox 4.2?

  - by Fat Bloke

  A year is a long time in the IT industry. Since the last VirtualBox feature release, which was a little over a year ago, we've seen: new releases of cool new operating systems, such as Windows 8, ChromeOS, and Mountain Lion; we've seen a myriad of new Linux releases from big Enterprise class distributions like Oracle 6.3, to accessible desktop distros like Ubuntu 12.04 and Fedora 17; and we've also seen the spec of a typical PC or laptop double in power. All of these events have influenced our new VirtualBox version which we're releasing today. Here's how... Powerful hosts  One of the trends we've seen is that as the average host platform becomes more powerful, our users are consistently running more and more vm's. Some of our users have large libraries of vm's of various vintages, whilst others have groups of vm's that are run together as an assembly of the various tiers in a multi-tiered software solution, for example, a database tier, middleware tier, and front-ends.  So we're pleased to unveil a more powerful VirtualBox Manager to address the needs of these users: VM Groups Groups allow you to organize your VM library in a sensible way, e.g.  by platform type, by project, by version, by whatever. To create groups you can drag one VM onto another or select one or more VM's and choose Machine...Group from the menu bar. You can expand and collapse groups to save screen real estate, and you can Enter and Leave a group (think iPad navigation here) by using the right and left arrow keys when groups are selected. But groups are more than passive folders, because you can now also perform operations on groups, rather than all the individual VMs. So if you have a multi-tiered solution you can start the whole stack up with just one click. Autostart Many VirtualBox users run dedicated services in their VMs, for example, running a Wiki. With these types of VM workloads, you really want the VM start up when the host machine boots up. So with 4.2 we've introduced a cross-platform Auto-start mechanism to allow you to treat VMs as host services. Headless VM Launching With VM's such as web servers, wikis, and other types of server-class workloads, the Console of the VM is pretty much redundant. For some time now VirtualBox has offered a separate launch mechanism for these VM's, namely the command-line interface commands VBoxHeadless or VBoxManage startvm ... --type headless commands. But with 4.2 we also allow you launch headless VMs from the Manager. Simply hold down Shift when launching the VM from the Manager.  It's that easy. But how do you stop a headless VM? Well, with 4.2 we allow you to Close the VM from the Manager. (BTW best to use the ACPI Shutdown method which allows the guest VM to close down gracefully.) Easy VM Creation For our expert users, the  New VM Wizard was a little tiresome, so now there's a faster 2-click VM creation mode. Just Hide the description when creating a new VM. Powerful VMs  As the hosts have become more powerful, so are the guests that are running inside them. Here are some of the 4.2 features to accommodate them: Virtual Network Interface Cards  With 4.2, it's now possible to create VMs with up to 36 NICs, when using the ICH9 chipset emulation. But with great power comes great responsibility (didn't Obi-Wan say something similar?), and so we have also introduced bandwidth limiting to prevent a rogue VM stealing the whole pipe. VLAN tagging Some of our users leverage VLANs extensively so we've enhanced the E1000 NICs to support this.  Processor Performance If you are running a CPU which supports Nested Paging (aka EPT in the Intel world) such as most of the Core i5 and i7 CPUs, or are running an AMD Bulldozer or later, you should see some performance improvements from our work with these processors. And while we're talking Processors, we've added support for some of the more modern VIA CPUs too. Powerful Automation Because VirtualBox runs atop a fully blown operating system, it makes sense to leverage the capabilities of the host to run scripts that can drive the guest VMs. Guest Automation was introduced in a prior release but with 4.2 we've revamped the APIs to allow a richer and more powerful set of operations to be executed by the guest. Check out the IGuest APIs in the VirtualBox Programming Guide and Reference (SDK). Powerful Platforms  All the hardcore engineering that has gone into 4.2 has been done for a purpose and that is to deliver a fast and powerful engine that can run almost any x86 OS because of the integrity of the virtualization. So we're pleased to add support for these platforms: Mac OS X "Mountain Lion"  Windows 8 Windows Server 2012 Ubuntu 12.04 (“Precise Pangolin”) Fedora 17 Oracle Linux 6.3  Here's the proof: We don't have time to go into the myriad of smaller improvements such as support for burning audio CDs from a guest, bi-directional clipboard control,  drag-and-drop of files into Linux guests, etc. so we'll leave that as an exercise for the user as soon as you've downloaded from the Oracle or community site and taken a peek at the User Guide. So all in all, a pretty solid release, one that we hope you'll enjoy discovering. - FB 

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• Plagued by multithreaded bugs

  - by koncurrency

  On my new team that I manage, the majority of our code is platform, TCP socket, and http networking code. All C++. Most of it originated from other developers that have left the team. The current developers on the team are very smart, but mostly junior in terms of experience. Our biggest problem: multi-threaded concurrency bugs. Most of our class libraries are written to be asynchronous by use of some thread pool classes. Methods on the class libraries often enqueue long running taks onto the thread pool from one thread and then the callback methods of that class get invoked on a different thread. As a result, we have a lot of edge case bugs involving incorrect threading assumptions. This results in subtle bugs that go beyond just having critical sections and locks to guard against concurrency issues. What makes these problems even harder is that the attempts to fix are often incorrect. Some mistakes I've observed the team attempting (or within the legacy code itself) includes something like the following: Common mistake #1 - Fixing concurrency issue by just put a lock around the shared data, but forgetting about what happens when methods don't get called in an expected order. Here's a very simple example: void Foo::OnHttpRequestComplete(statuscode status) { m_pBar->DoSomethingImportant(status); } void Foo::Shutdown() { m_pBar->Cleanup(); delete m_pBar; m_pBar=nullptr; } So now we have a bug in which Shutdown could get called while OnHttpNetworkRequestComplete is occuring on. A tester finds the bug, captures the crash dump, and assigns the bug to a developer. He in turn fixes the bug like this. void Foo::OnHttpRequestComplete(statuscode status) { AutoLock lock(m_cs); m_pBar->DoSomethingImportant(status); } void Foo::Shutdown() { AutoLock lock(m_cs); m_pBar->Cleanup(); delete m_pBar; m_pBar=nullptr; } The above fix looks good until you realize there's an even more subtle edge case. What happens if Shutdown gets called before OnHttpRequestComplete gets called back? The real world examples my team has are even more complex, and the edge cases are even harder to spot during the code review process. Common Mistake #2 - fixing deadlock issues by blindly exiting the lock, wait for the other thread to finish, then re-enter the lock - but without handling the case that the object just got updated by the other thread! Common Mistake #3 - Even though the objects are reference counted, the shutdown sequence "releases" it's pointer. But forgets to wait for the thread that is still running to release it's instance. As such, components are shutdown cleanly, then spurious or late callbacks are invoked on an object in an state not expecting any more calls. There are other edge cases, but the bottom line is this: Multithreaded programming is just plain hard, even for smart people. As I catch these mistakes, I spend time discussing the errors with each developer on developing a more appropriate fix. But I suspect they are often confused on how to solve each issue because of the enormous amount of legacy code that the "right" fix will involve touching. We're going to be shipping soon, and I'm sure the patches we're applying will hold for the upcoming release. Afterwards, we're going to have some time to improve the code base and refactor where needed. We won't have time to just re-write everything. And the majority of the code isn't all that bad. But I'm looking to refactor code such that threading issues can be avoided altogether. One approach I am considering is this. For each significant platform feature, have a dedicated single thread where all events and network callbacks get marshalled onto. Similar to COM apartment threading in Windows with use of a message loop. Long blocking operations could still get dispatched to a work pool thread, but the completion callback is invoked on on the component's thread. Components could possibly even share the same thread. Then all the class libraries running inside the thread can be written under the assumption of a single threaded world. Before I go down that path, I am also very interested if there are other standard techniques or design patterns for dealing with multithreaded issues. And I have to emphasize - something beyond a book that describes the basics of mutexes and semaphores. What do you think? I am also interested in any other approaches to take towards a refactoring process. Including any of the following: Literature or papers on design patterns around threads. Something beyond an introduction to mutexes and semaphores. We don't need massive parallelism either, just ways to design an object model so as to handle asynchronous events from other threads correctly. Ways to diagram the threading of various components, so that it will be easy to study and evolve solutions for. (That is, a UML equivalent for discussing threads across objects and classes) Educating your development team on the issues with multithreaded code. What would you do?

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• spring security : Failed to load ApplicationContext with pre-post-annotations="enabled"

  - by thogau

  I am using spring 3.0.1 + spring-security 3.0.2 and I am trying to use features like @PreAuthorize and @PostFilter annotations. When running in units tests using @RunWith(SpringJUnit4ClassRunner.class) or in a main(String[] args) method my application context fails to start if enable pre-post-annotations and use org.springframework.security.acls.AclPermissionEvaluator : <!-- Enable method level security--> <security:global-method-security pre-post-annotations="enabled"> <security:expression-handler ref="expressionHandler"/> </security:global-method-security> <bean id="expressionHandler" class="org.springframework.security.access.expression.method.DefaultMethodSecurityExpressionHandler"> <property name="permissionEvaluator" ref="aclPermissionEvaluator"/> </bean> <bean id="aclPermissionEvaluator" class="org.springframework.security.acls.AclPermissionEvaluator"> <constructor-arg ref="aclService"/> </bean> <!-- Enable stereotype support --> <context:annotation-config /> <context:component-scan base-package="com.rreps.core" /> <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="locations"> <list> <value>classpath:applicationContext.properties</value> </list> </property> </bean> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="driverClass" value="${jdbc.driver}" /> <property name="jdbcUrl" value="${jdbc.url}" /> <property name="user" value="${jdbc.username}" /> <property name="password" value="${jdbc.password}" /> <property name="initialPoolSize" value="10" /> <property name="minPoolSize" value="5" /> <property name="maxPoolSize" value="25" /> <property name="acquireRetryAttempts" value="10" /> <property name="acquireIncrement" value="5" /> <property name="idleConnectionTestPeriod" value="3600" /> <property name="maxIdleTime" value="10800" /> <property name="maxConnectionAge" value="14400" /> <property name="preferredTestQuery" value="SELECT 1;" /> <property name="testConnectionOnCheckin" value="false" /> </bean> <bean id="auditedSessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean"> <property name="dataSource" ref="dataSource" /> <property name="configLocation" value="classpath:hibernate.cfg.xml" /> <property name="hibernateProperties"> <value> hibernate.dialect=${hibernate.dialect} hibernate.query.substitutions=true 'Y', false 'N' hibernate.cache.use_second_level_cache=true hibernate.cache.provider_class=net.sf.ehcache.hibernate.SingletonEhCacheProvider hibernate.hbm2ddl.auto=update hibernate.c3p0.acquire_increment=5 hibernate.c3p0.idle_test_period=3600 hibernate.c3p0.timeout=10800 hibernate.c3p0.max_size=25 hibernate.c3p0.min_size=1 hibernate.show_sql=false hibernate.validator.autoregister_listeners=false </value> </property> <!-- validation is performed by "hand" (see http://opensource.atlassian.com/projects/hibernate/browse/HV-281) <property name="eventListeners"> <map> <entry key="pre-insert" value-ref="beanValidationEventListener" /> <entry key="pre-update" value-ref="beanValidationEventListener" /> </map> </property> --> <property name="entityInterceptor"> <bean class="com.rreps.core.dao.hibernate.interceptor.TrackingInterceptor" /> </property> </bean> <bean id="simpleSessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean"> <property name="dataSource" ref="dataSource" /> <property name="configLocation" value="classpath:hibernate.cfg.xml" /> <property name="hibernateProperties"> <value> hibernate.dialect=${hibernate.dialect} hibernate.query.substitutions=true 'Y', false 'N' hibernate.cache.use_second_level_cache=true hibernate.cache.provider_class=net.sf.ehcache.hibernate.SingletonEhCacheProvider hibernate.hbm2ddl.auto=update hibernate.c3p0.acquire_increment=5 hibernate.c3p0.idle_test_period=3600 hibernate.c3p0.timeout=10800 hibernate.c3p0.max_size=25 hibernate.c3p0.min_size=1 hibernate.show_sql=false hibernate.validator.autoregister_listeners=false </value> </property> <!-- property name="eventListeners"> <map> <entry key="pre-insert" value-ref="beanValidationEventListener" /> <entry key="pre-update" value-ref="beanValidationEventListener" /> </map> </property--> </bean> <bean id="sequenceSessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean"> <property name="dataSource" ref="dataSource" /> <property name="configLocation" value="classpath:hibernate.cfg.xml" /> <property name="hibernateProperties"> <value> hibernate.dialect=${hibernate.dialect} hibernate.query.substitutions=true 'Y', false 'N' hibernate.cache.use_second_level_cache=true hibernate.cache.provider_class=net.sf.ehcache.hibernate.SingletonEhCacheProvider hibernate.hbm2ddl.auto=update hibernate.c3p0.acquire_increment=5 hibernate.c3p0.idle_test_period=3600 hibernate.c3p0.timeout=10800 hibernate.c3p0.max_size=25 hibernate.c3p0.min_size=1 hibernate.show_sql=false hibernate.validator.autoregister_listeners=false </value> </property> </bean> <bean id="validationFactory" class="javax.validation.Validation" factory-method="buildDefaultValidatorFactory" /> <!-- bean id="beanValidationEventListener" class="org.hibernate.cfg.beanvalidation.BeanValidationEventListener"> <constructor-arg index="0" ref="validationFactory" /> <constructor-arg index="1"> <props/> </constructor-arg> </bean--> <!-- Enable @Transactional support --> <tx:annotation-driven transaction-manager="transactionManager"/> <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager"> <property name="sessionFactory" ref="auditedSessionFactory" /> </bean> <security:authentication-manager alias="authenticationManager"> <security:authentication-provider user-service-ref="userDetailsService" /> </security:authentication-manager> <bean id="userDetailsService" class="com.rreps.core.service.impl.UserDetailsServiceImpl" /> <!-- ACL stuff --> <bean id="aclCache" class="org.springframework.security.acls.domain.EhCacheBasedAclCache"> <constructor-arg> <bean class="org.springframework.cache.ehcache.EhCacheFactoryBean"> <property name="cacheManager"> <bean class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean"/> </property> <property name="cacheName" value="aclCache"/> </bean> </constructor-arg> </bean> <bean id="lookupStrategy" class="org.springframework.security.acls.jdbc.BasicLookupStrategy"> <constructor-arg ref="dataSource"/> <constructor-arg ref="aclCache"/> <constructor-arg> <bean class="org.springframework.security.acls.domain.AclAuthorizationStrategyImpl"> <constructor-arg> <list> <bean class="org.springframework.security.core.authority.GrantedAuthorityImpl"> <constructor-arg value="ROLE_ADMINISTRATEUR"/> </bean> <bean class="org.springframework.security.core.authority.GrantedAuthorityImpl"> <constructor-arg value="ROLE_ADMINISTRATEUR"/> </bean> <bean class="org.springframework.security.core.authority.GrantedAuthorityImpl"> <constructor-arg value="ROLE_ADMINISTRATEUR"/> </bean> </list> </constructor-arg> </bean> </constructor-arg> <constructor-arg> <bean class="org.springframework.security.acls.domain.ConsoleAuditLogger"/> </constructor-arg> </bean> <bean id="aclService" class="com.rreps.core.service.impl.MysqlJdbcMutableAclService"> <constructor-arg ref="dataSource"/> <constructor-arg ref="lookupStrategy"/> <constructor-arg ref="aclCache"/> </bean> The strange thing is that the context starts normally when deployed in a webapp and @PreAuthorize and @PostFilter annotations are working fine as well... Any idea what is wrong? Here is the end of the stacktrace : ... 55 more Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [applicationContext-core.xml]: Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.transaction.config.internalTransactionAdvisor': Cannot resolve reference to bean 'org.springframework.transaction.annotation.AnnotationTransactionAttributeSource#0' while setting bean property 'transactionAttributeSource'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.transaction.annotation.AnnotationTransactionAttributeSource#0': Initialization of bean failed; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:521) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:450) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:290) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:287) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:189) at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:322) ... 67 more Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.transaction.config.internalTransactionAdvisor': Cannot resolve reference to bean 'org.springframework.transaction.annotation.AnnotationTransactionAttributeSource#0' while setting bean property 'transactionAttributeSource'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.transaction.annotation.AnnotationTransactionAttributeSource#0': Initialization of bean failed; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:328) at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:106) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1308) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1067) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:511) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:450) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:290) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:287) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193) at org.springframework.aop.framework.autoproxy.BeanFactoryAdvisorRetrievalHelper.findAdvisorBeans(BeanFactoryAdvisorRetrievalHelper.java:86) at org.springframework.aop.framework.autoproxy.AbstractAdvisorAutoProxyCreator.findCandidateAdvisors(AbstractAdvisorAutoProxyCreator.java:100) at org.springframework.aop.framework.autoproxy.AbstractAdvisorAutoProxyCreator.findEligibleAdvisors(AbstractAdvisorAutoProxyCreator.java:86) at org.springframework.aop.framework.autoproxy.AbstractAdvisorAutoProxyCreator.getAdvicesAndAdvisorsForBean(AbstractAdvisorAutoProxyCreator.java:68) at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.wrapIfNecessary(AbstractAutoProxyCreator.java:359) at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.postProcessAfterInitialization(AbstractAutoProxyCreator.java:322) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsAfterInitialization(AbstractAutowireCapableBeanFactory.java:404) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1409) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) ... 73 more Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.transaction.annotation.AnnotationTransactionAttributeSource#0': Initialization of bean failed; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:521) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:450) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:290) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:287) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:189) at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:322) ... 91 more Caused by: java.lang.NullPointerException at org.springframework.security.access.method.DelegatingMethodSecurityMetadataSource.getAttributes(DelegatingMethodSecurityMetadataSource.java:52) at org.springframework.security.access.intercept.aopalliance.MethodSecurityMetadataSourceAdvisor$MethodSecurityMetadataSourcePointcut.matches(MethodSecurityMetadataSourceAdvisor.java:129) at org.springframework.aop.support.AopUtils.canApply(AopUtils.java:215) at org.springframework.aop.support.AopUtils.canApply(AopUtils.java:252) at org.springframework.aop.support.AopUtils.findAdvisorsThatCanApply(AopUtils.java:284) at org.springframework.aop.framework.autoproxy.AbstractAdvisorAutoProxyCreator.findAdvisorsThatCanApply(AbstractAdvisorAutoProxyCreator.java:117) at org.springframework.aop.framework.autoproxy.AbstractAdvisorAutoProxyCreator.findEligibleAdvisors(AbstractAdvisorAutoProxyCreator.java:87) at org.springframework.aop.framework.autoproxy.AbstractAdvisorAutoProxyCreator.getAdvicesAndAdvisorsForBean(AbstractAdvisorAutoProxyCreator.java:68) at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.wrapIfNecessary(AbstractAutoProxyCreator.java:359) at org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.postProcessAfterInitialization(AbstractAutoProxyCreator.java:322) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsAfterInitialization(AbstractAutowireCapableBeanFactory.java:404) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1409) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) ... 97 more

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• Connection to Weblogic Server through ServiceMix fails

  - by bertolami

  I connect from a OSGi bundle deployed on Apache ServiceMix to a Weblogic Server to call some EJBs. The lookup happens with JNDI. In my unit test everything works fine. But when a deploy the bundle on ServiceMix a CommunicationException exception is raised on JNDI ContextFactory initialisation. The class that performs the lookup during initialisation: public DummyJndiLookup(JndiTemplate jndiTemplate) { try { String securityServiceURL = "ejb/xyz/Service"; reference = jndiTemplate.lookup(securityServiceURL); log.info("Successfully connected to JNDI Server: " + reference); } catch (Throwable t) { throw new RuntimeException(t); } } The beans in the spring context: <bean id="dummy" class="xyz.DummyJndiLookup"> <constructor-arg ref="jndiTemplate"></constructor-arg> </bean> <bean id="jndiTemplate" class="org.springframework.jndi.JndiTemplate" lazy-init="true"> <property name="environment"> <props> <prop key="java.naming.factory.initial">weblogic.jndi.WLInitialContextFactory</prop> <prop key="java.naming.provider.url">t3://xyz:22225</prop> <prop key="java.naming.security.principal">weblogic</prop> <prop key="java.naming.security.credentials">weblogic</prop> </props> </property> </bean> The resulting exception stack trace: Caused by: javax.naming.CommunicationException [Root exception is java.net.ConnectException: t3://xyz7:22225: Bootstrap to: xyz/192.168.108.22:22225' over: 't3' got an error or timed out] at weblogic.jndi.internal.ExceptionTranslator.toNamingException(ExceptionTranslator.java:40) at weblogic.jndi.WLInitialContextFactoryDelegate.toNamingException(WLInitialContextFactoryDelegate.java:783) at weblogic.jndi.WLInitialContextFactoryDelegate.getInitialContext(WLInitialContextFactoryDelegate.java:365) at weblogic.jndi.Environment.getContext(Environment.java:315) at weblogic.jndi.Environment.getContext(Environment.java:285) at weblogic.jndi.WLInitialContextFactory.getInitialContext(WLInitialContextFactory.java:117) at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:667) at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:288) at javax.naming.InitialContext.init(InitialContext.java:223) at javax.naming.InitialContext.<init>(InitialContext.java:197) at org.springframework.jndi.JndiTemplate.createInitialContext(JndiTemplate.java:137) at org.springframework.jndi.JndiTemplate.getContext(JndiTemplate.java:104) at org.springframework.jndi.JndiTemplate.execute(JndiTemplate.java:86) at org.springframework.jndi.JndiTemplate.lookup(JndiTemplate.java:153) at xyz.DummyJndiLookup.<init>(DummyJndiLookup.java:36) ... 26 more Caused by: java.net.ConnectException: t3://xyz:22225: Bootstrap to: xyz/192.168.108.22:22225' over: 't3' got an error or timed out at weblogic.rjvm.RJVMFinder.findOrCreateInternal(RJVMFinder.java:216) at weblogic.rjvm.RJVMFinder.findOrCreate(RJVMFinder.java:170) at weblogic.rjvm.ServerURL.findOrCreateRJVM(ServerURL.java:153) at weblogic.jndi.WLInitialContextFactoryDelegate$1.run(WLInitialContextFactoryDelegate.java:344) at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:363) at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:147) at weblogic.jndi.WLInitialContextFactoryDelegate.getInitialContext(WLInitialContextFactoryDelegate.java:339) ... 38 more Caused by: java.rmi.ConnectException: Bootstrap to: xyz/192.168.108.22:22225' over: 't3' got an error or timed out at weblogic.rjvm.ConnectionManager.bootstrap(ConnectionManager.java:359) at weblogic.rjvm.RJVMManager.findOrCreateRemoteInternal(RJVMManager.java:251) at weblogic.rjvm.RJVMManager.findOrCreate(RJVMManager.java:194) at weblogic.rjvm.RJVMFinder.findOrCreateRemoteServer(RJVMFinder.java:238) at weblogic.rjvm.RJVMFinder.findOrCreateInternal(RJVMFinder.java:200) Any ideas what could cause the exception? Escpecially why it does work in the unit test and not after having bundled and deployed on Apache ServiceMix? Additional Info: I dumped the threads stack trace of ServiceMix (after having removed all JNDI related spring stuff): 2010-03-22 16:18:23 Full thread dump Java HotSpot(TM) Server VM (11.2-b01 mixed mode): "SpringOsgiExtenderThread-14" prio=6 tid=0x054d6400 nid=0x17c4 waiting for monitor entry [0x06f3e000..0x06f3fb14] java.lang.Thread.State: BLOCKED (on object monitor) at weblogic.rjvm.RJVMFinder.findOrCreate(RJVMFinder.java:168) - waiting to lock <0x595876f8> (a weblogic.rjvm.RJVMFinder) at weblogic.rjvm.ServerURL.findOrCreateRJVM(ServerURL.java:153) at weblogic.jndi.WLInitialContextFactoryDelegate.getInitialContext(WLInitialContextFactoryDelegate.java:352) at weblogic.jndi.Environment.getContext(Environment.java:315) at weblogic.jndi.Environment.getContext(Environment.java:285) at weblogic.jndi.WLInitialContextFactory.getInitialContext(WLInitialContextFactory.java:117) at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:667) at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:288) at javax.naming.InitialContext.init(InitialContext.java:223) at javax.naming.InitialContext.<init>(InitialContext.java:197) at xyz.DummyJndiLookup.getInitialContext(DummyJndiLookup.java:62) at xyz.DummyJndiLookup.<init>(DummyJndiLookup.java:32) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:100) at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:61) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:877) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:839) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:440) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:409) at java.security.AccessController.doPrivileged(Native Method) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:380) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:264) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) - locked <0x595959c0> (a java.util.concurrent.ConcurrentHashMap) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:261) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:185) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:164) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:429) - locked <0x59598370> (a java.util.concurrent.ConcurrentHashMap) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:728) at org.springframework.osgi.context.support.AbstractDelegatedExecutionApplicationContext.access$1600(AbstractDelegatedExecutionApplicationContext.java:69) at org.springframework.osgi.context.support.AbstractDelegatedExecutionApplicationContext$4.run(AbstractDelegatedExecutionApplicationContext.java:355) - locked <0x595431a8> (a java.lang.Object) at org.springframework.osgi.util.internal.PrivilegedUtils.executeWithCustomTCCL(PrivilegedUtils.java:85) at org.springframework.osgi.context.support.AbstractDelegatedExecutionApplicationContext.completeRefresh(AbstractDelegatedExecutionApplicationContext.java:320) at org.springframework.osgi.extender.internal.dependencies.startup.DependencyWaiterApplicationContextExecutor$CompleteRefreshTask.run(DependencyWaiterApplicationContextExecutor.java:136) at java.lang.Thread.run(Thread.java:619) Locked ownable synchronizers: - None "SpringOsgiExtenderThread-12" prio=6 tid=0x05465400 nid=0x14cc in Object.wait() [0x06f8e000..0x06f8fc94] java.lang.Thread.State: TIMED_WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x595b3800> (a java.lang.Object) at weblogic.rjvm.ConnectionManager.bootstrap(ConnectionManager.java:320) - locked <0x595b3800> (a java.lang.Object) at weblogic.rjvm.RJVMManager.findOrCreateRemoteInternal(RJVMManager.java:251) - locked <0x595885b8> (a java.lang.Object) at weblogic.rjvm.RJVMManager.findOrCreate(RJVMManager.java:194) at weblogic.rjvm.RJVMFinder.findOrCreateRemoteServer(RJVMFinder.java:238) at weblogic.rjvm.RJVMFinder.findOrCreateInternal(RJVMFinder.java:200) at weblogic.rjvm.RJVMFinder.findOrCreate(RJVMFinder.java:170) - locked <0x595876f8> (a weblogic.rjvm.RJVMFinder) at weblogic.rjvm.ServerURL.findOrCreateRJVM(ServerURL.java:153) at weblogic.jndi.WLInitialContextFactoryDelegate.getInitialContext(WLInitialContextFactoryDelegate.java:352) at weblogic.jndi.Environment.getContext(Environment.java:315) at weblogic.jndi.Environment.getContext(Environment.java:285) at weblogic.jndi.WLInitialContextFactory.getInitialContext(WLInitialContextFactory.java:117) at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:667) at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:288) at javax.naming.InitialContext.init(InitialContext.java:223) at javax.naming.InitialContext.<init>(InitialContext.java:197) at xyz.DummyJndiLookup.getInitialContext(DummyJndiLookup.java:62) at xyz.DummyJndiLookup.<init>(DummyJndiLookup.java:32) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:100) at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:61) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:877) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:839) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:440) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:409) at java.security.AccessController.doPrivileged(Native Method) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:380) at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:264) at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) - locked <0x595b3af0> (a java.util.concurrent.ConcurrentHashMap) at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:261) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:185) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:164) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:429) - locked <0x595b3b18> (a java.util.concurrent.ConcurrentHashMap) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:728) at org.springframework.osgi.context.support.AbstractDelegatedExecutionApplicationContext.access$1600(AbstractDelegatedExecutionApplicationContext.java:69) at org.springframework.osgi.context.support.AbstractDelegatedExecutionApplicationContext$4.run(AbstractDelegatedExecutionApplicationContext.java:355) - locked <0x595b3be0> (a java.lang.Object) at org.springframework.osgi.util.internal.PrivilegedUtils.executeWithCustomTCCL(PrivilegedUtils.java:85) at org.springframework.osgi.context.support.AbstractDelegatedExecutionApplicationContext.completeRefresh(AbstractDelegatedExecutionApplicationContext.java:320) at org.springframework.osgi.extender.internal.dependencies.startup.DependencyWaiterApplicationContextExecutor$CompleteRefreshTask.run(DependencyWaiterApplicationContextExecutor.java:136) at java.lang.Thread.run(Thread.java:619) Locked ownable synchronizers: - None "RMI TCP Connection(idle)" daemon prio=6 tid=0x05329400 nid=0x1100 waiting on condition [0x069af000..0x069afa14] java.lang.Thread.State: TIMED_WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <0x200a1380> (a java.util.concurrent.SynchronousQueue$TransferStack) at java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:198) at java.util.concurrent.SynchronousQueue$TransferStack.awaitFulfill(SynchronousQueue.java:424) at java.util.concurrent.SynchronousQueue$TransferStack.transfer(SynchronousQueue.java:323) at java.util.conCurrent.SynchronousQueue.poll(SynchronousQueue.java:874) at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:945) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907) at java.lang.Thread.run(Thread.java:619) Locked ownable synchronizers: - None "Timer-4" daemon prio=6 tid=0x053aa400 nid=0xfa4 in Object.wait() [0x06eef000..0x06eefc94] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x59585388> (a java.util.TaskQueue) at java.lang.Object.wait(Object.java:485) at java.util.TimerThread.mainLoop(Timer.java:483) - locked <0x59585388> (a java.util.TaskQueue) at java.util.TimerThread.run(Timer.java:462) Locked ownable synchronizers: - None "weblogic.timers.TimerThread" daemon prio=10 tid=0x05151800 nid=0x11fc in Object.wait() [0x06e9f000..0x06e9fd14] java.lang.Thread.State: TIMED_WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x5959c3c0> (a weblogic.timers.internal.TimerThread) at weblogic.timers.internal.TimerThread$Thread.run(TimerThread.java:267) - locked <0x5959c3c0> (a weblogic.timers.internal.TimerThread) Locked ownable synchronizers: - None "ExecuteThread: '4' for queue: 'default'" daemon prio=6 tid=0x04880c00 nid=0x117c in Object.wait() [0x06e4f000..0x06e4fd94] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x595855a8> (a weblogic.kernel.ServerExecuteThread) at java.lang.Object.wait(Object.java:485) at weblogic.kernel.ExecuteThread.waitForRequest(ExecuteThread.java:91) - locked <0x595855a8> (a weblogic.kernel.ServerExecuteThread) at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:115) Locked ownable synchronizers: - None "ExecuteThread: '3' for queue: 'default'" daemon prio=6 tid=0x05242400 nid=0xd34 in Object.wait() [0x06dff000..0x06dffa14] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x59585998> (a weblogic.kernel.ServerExecuteThread) at java.lang.Object.wait(Object.java:485) at weblogic.kernel.ExecuteThread.waitForRequest(ExecuteThread.java:91) - locked <0x59585998> (a weblogic.kernel.ServerExecuteThread) at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:115) Locked ownable synchronizers: - None "ExecuteThread: '2' for queue: 'default'" daemon prio=6 tid=0x04509800 nid=0x1600 in Object.wait() [0x06daf000..0x06dafa94] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x59585c78> (a weblogic.kernel.ServerExecuteThread) at java.lang.Object.wait(Object.java:485) at weblogic.kernel.ExecuteThread.waitForRequest(ExecuteThread.java:91) - locked <0x59585c78> (a weblogic.kernel.ServerExecuteThread) at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:115) Locked ownable synchronizers: - None "ExecuteThread: '1' for queue: 'default'" daemon prio=6 tid=0x05170800 nid=0x894 in Object.wait() [0x06d5f000..0x06d5fb14] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x59585f58> (a weblogic.kernel.ServerExecuteThread) at java.lang.Object.wait(Object.java:485) at weblogic.kernel.ExecuteThread.waitForRequest(ExecuteThread.java:91) - locked <0x59585f58> (a weblogic.kernel.ServerExecuteThread) at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:115) Locked ownable synchronizers: - None "ExecuteThread: '0' for queue: 'default'" daemon prio=6 tid=0x05329800 nid=0x10a8 in Object.wait() [0x06c1f000..0x06c1fb94] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x59586238> (a weblogic.kernel.ServerExecuteThread) at java.lang.Object.wait(Object.java:485) at weblogic.kernel.ExecuteThread.waitForRequest(ExecuteThread.java:91) - locked <0x59586238> (a weblogic.kernel.ServerExecuteThread) at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:115) Locked ownable synchronizers: - None "Timer-3" daemon prio=6 tid=0x0484bc00 nid=0xebc waiting for monitor entry [0x06cbf000..0x06cbfa94] java.lang.Thread.State: BLOCKED (on object monitor) at org.springframework.osgi.extender.internal.dependencies.startup.DependencyWaiterApplicationContextExecutor.close(DependencyWaiterApplicationContextExecutor.java:355) - waiting to lock <0x595b3be0> (a java.lang.Object) - locked <0x595b3c48> (a java.lang.Object) at org.springframework.osgi.context.support.AbstractDelegatedExecutionApplicationContext.doClose(AbstractDelegatedExecutionApplicationContext.java:236) at org.springframework.context.support.AbstractApplicationContext.close(AbstractApplicationContext.java:794) - locked <0x595b4128> (a java.lang.Object) at org.springframework.osgi.extender.internal.activator.ContextLoaderListener$3.run(ContextLoaderListener.java:807) at org.springframework.osgi.extender.internal.util.concurrent.RunnableTimedExecution$MonitoredRunnable.run(RunnableTimedExecution.java:60) at org.springframework.scheduling.timer.DelegatingTimerTask.run(DelegatingTimerTask.java:66) at java.util.TimerThread.mainLoop(Timer.java:512) at java.util.TimerThread.run(Timer.java:462) Locked ownable synchronizers: - None "Timer-2" daemon prio=6 tid=0x04780400 nid=0x1388 in Object.wait() [0x06c6f000..0x06c6fb14] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x20783b60> (a java.util.TaskQueue) at java.lang.Object.wait(Object.java:485) at java.util.TimerThread.mainLoop(Timer.java:483) - locked <0x20783b60> (a java.util.TaskQueue) at java.util.TimerThread.run(Timer.java:462) Locked ownable synchronizers: - None "AWT-Windows" daemon prio=6 tid=0x04028000 nid=0x83c runnable [0x06b8f000..0x06b8fb14] java.lang.Thread.State: RUNNABLE at sun.awt.windows.WToolkit.eventLoop(Native Method) at sun.awt.windows.WToolkit.run(WToolkit.java:291) at java.lang.Thread.run(Thread.java:619) Locked ownable synchronizers: - None "Java2D Disposer" daemon prio=10 tid=0x0469c400 nid=0x1164 in Object.wait() [0x0695f000..0x0695fc14] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x206f4200> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:116) - locked <0x206f4200> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:132) at sun.java2d.Disposer.run(Disposer.java:125) at java.lang.Thread.run(Thread.java:619) Locked ownable synchronizers: - None "NioSocketAcceptor-1" prio=6 tid=0x055acc00 nid=0xf80 runnable [0x068bf000..0x068bfd94] java.lang.Thread.State: RUNNABLE at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll0(Native Method) at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll(WindowsSelectorImpl.java:274) at sun.nio.ch.WindowsSelectorImpl$SubSelector.access$400(WindowsSelectorImpl.java:256) at sun.nio.ch.WindowsSelectorImpl.doSelect(WindowsSelectorImpl.java:137) at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:69) - locked <0x2069e820> (a sun.nio.ch.Util$1) - locked <0x2069e810> (a java.util.Collections$UnmodifiableSet) - locked <0x2069e3d8> (a sun.nio.ch.WindowsSelectorImpl) at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:80) at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:84) at org.apache.mina.transport.socket.nio.NioSocketAcceptor.select(NioSocketAcceptor.java:288) at org.apache.mina.core.polling.AbstractPollingIoAcceptor$Acceptor.run(AbstractPollingIoAcceptor.java:402) at org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:64) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) at java.lang.Thread.run(Thread.java:619) Locked ownable synchronizers: - <0x2069e0f8> (a java.util.concurrent.locks.ReentrantLock$NonfairSync) "RMI RenewClean-[192.168.114.60:1640]" daemon prio=6 tid=0x05312400 nid=0x1058 in Object.wait() [0x06b3f000..0x06b3fa94] java.lang.Thread.State: TIMED_WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x20669858> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:116) - locked <0x20669858> (a java.lang.ref.ReferenceQueue$Lock) at sun.rmi.transport.DGCClient$EndpointEntry$RenewCleanThread.run(DGCClient.java:516) at java.lang.Thread.run(Thread.java:619) Locked ownable synchronizers: - None "RMI Scheduler(0)" daemon prio=6 tid=0x05132800 nid=0x146c waiting on condition [0x06aef000..0x06aefb14] java.lang.Thread.State: TIMED_WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <0x200a1508> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject) at java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:198) at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:1963) at java.util.concurrent.DelayQueue.take(DelayQueue.java:164) at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:583) at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:576) at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:947) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907) at java.lang.Thread.run(Thread.java:619) Locked ownable synchronizers: - None "GC Daemon" daemon prio=2 tid=0x05678400 nid=0x166c in Object.wait() [0x06a9f000..0x06a9fc14] java.lang.Thread.State: TIMED_WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x2060d790> (a sun.misc.GC$LatencyLock) at sun.misc.GC$Daemon.run(GC.java:100) - locked <0x2060d790> (a sun.misc.GC$LatencyLock) Locked ownable synchronizers: - None "RMI Reaper" prio=6 tid=0x04fee800 nid=0x828 in Object.wait() [0x06a4f000..0x06a4fd14] java.lang.Thread.State: WAITING (on object monitor) at java.lang.Object.wait(Native Method) - waiting on <0x200a79c8> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:116) - locked <0x200a79c8> (a java.lang.ref.ReferenceQueue$Lock) at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:132) at sun.rmi.transport.ObjectTable$Reaper.run(ObjectTable.java:333) at java.lang.Thread.run(Thread.java:619) Locked ownable synchronizers: - None "RMI TCP Accept-0" daemon prio=6 tid=0x0488dc00 nid=0x129c runnable [0x069ff000..0x069ffc94] java.lang.Thread.State: RUNNABLE at java.net.PlainSocketImpl.socketAccept(Native Method) at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:384) - locked <0x20606780> (a java.net.SocksSocketImpl) at java.net.ServerSocket.implAccept(ServerSocket.java:453) at java.net.ServerSocket.accept(ServerSocket.java:421) at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.executeAcceptLoop(TCPTransport.java:369) at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.run(TCPTransport.java:341) at java.lang.Thread.run(Thread.java:619) Locked ownable synchronizers: - None "RMI TCP Accept-20220" daemon prio=6 tid=0x05319800 nid=0x1634 runnable [0x0690f000..0x0690fa94] java.lang.Thread.State: RUNNABLE at java.net.PlainSocketImpl.socketAccept(Native Method) at java.net.PlainSocketImpl.accept(PlainSocketImpl.java:384) - locked <0x205fb908> (a java.net.SocksSocketImpl) at java.net.ServerSocket.implAccept(ServerSocket.java:453) at java.net.ServerSocket.accept(ServerSocket.java:421) at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.executeAcceptLoop(TCPTransport.java:369) at sun.rmi.transport.tcp.TCPTransport$AcceptLoop.run(TCPTransport.java:341) at java.lang.Thread.run(Thread.java:619) Locked ownable synchronizers: - None "gogo shell pipe thread" daemon prio=6 tid=0x0511f400 nid=0x920 runnable [0x0586f000..0x0586fb94] java.lang.Thread.State: RUNNABLE at jline.WindowsTerminal.readByte(Native Method) at jline.WindowsTerminal.readCharacter(WindowsTerminal.java:237) at jline.AnsiWindowsTerminal.readDirectChar(AnsiWindowsTerminal.java:44) at org.apache.felix.karaf.shell.console.jline.Console$Pipe.run(Console.java:346) at java.lang.Thread.run(Thread.java:619) Locked ownable synchronizers: - None "Karaf Shell Console Thread" prio=6 tid=0x05134400 nid=0xf54 waiting on condition [0x0581f000..0x0581fc14] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <0x20573970> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:158) at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:1925) at java.util.concurrent.ArrayBlockingQueue.take(ArrayBlockingQueue.java:317) at org.apache.felix.karaf.shell.console.jline.Console$ConsoleInputStream.read(Console.java:286) at org.apache.felix.karaf.shell.console.jline.Console$ConsoleInputStream.read(Console.java:303) at jline.AnsiWindowsTerminal.readCharacter(AnsiWindowsTerminal.java:40) at jline.WindowsTerminal.readVirtualKey(WindowsTerminal.java:359) at jline.ConsoleReader.readVirtualKey(ConsoleReader.java:1504) at jline.ConsoleReader.readBinding(ConsoleReader.java:674) at jline.ConsoleReader.readLine(ConsoleReader.java:514) at jline.ConsoleReader.readLine(ConsoleReader.java:468) at org.apache.felix.karaf.shell.console.jline.Console.run(Console.java:169) at java.lang.Thread.run(Thread.java:619) Locked ownable synchronizers: - None "pool-2-thread-3" prio=6 tid=0x04522c00 nid=0xf7c waiting on condition [0x04f9f000..0x04f9fc94] java.lang.Thread.State: WAITING (parking) at sun.misc.Unsafe.park(Native Method) - parking to wait for <0x202a6220> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject) at ja

  Read the article

• Problems extracting information from RSS feed description field

  - by Graeme

  Hi, I've built an iPhone application using the parsing code from the TopSongs sample iPhone application. I've hit a problem though - the feed I'm trying to parse data from doesn't have a separate field for every piece of information (i.e. if it was for a feed about dogs, all the information such as dog type, dog age and dog price is contained in the feed. However, the TopSongs app relies on information having its own tags, so instead of using it uses and . So my question is this. How do I extract this information from the description field so that it can be parsed using the TopSongs parser? Can you somehow extract the dog age, price and type information using Yahoo Pipes and use that RSS feed for the feed? Or is there code that I can add to do it in application? Update: To view the code of my application parser (based on the TopSongs Core Data Apple provided application, see below. Here's a sample of one item from the the actual RSS feed I'm using (the description is longer, and has status,size, and a couple of other fields, but they're all formatted the same.: <item> <title>MOE, MARGRET STREET</title> <description> <b>District/Region:</b>&nbsp;REGION 09</br><b>Location:</b>&nbsp;MOE</br><b>Name:</b>&nbsp;MARGRET STREET</br></description> <pubDate>Thu,11 Mar 2010 05:43:03 GMT</pubDate> <guid>1266148</guid> </item> /* File: iTunesRSSImporter.m Abstract: Downloads, parses, and imports the iTunes top songs RSS feed into Core Data. Version: 1.1 Disclaimer: IMPORTANT: This Apple software is supplied to you by Apple Inc. ("Apple") in consideration of your agreement to the following terms, and your use, installation, modification or redistribution of this Apple software constitutes acceptance of these terms. If you do not agree with these terms, please do not use, install, modify or redistribute this Apple software. In consideration of your agreement to abide by the following terms, and subject to these terms, Apple grants you a personal, non-exclusive license, under Apple's copyrights in this original Apple software (the "Apple Software"), to use, reproduce, modify and redistribute the Apple Software, with or without modifications, in source and/or binary forms; provided that if you redistribute the Apple Software in its entirety and without modifications, you must retain this notice and the following text and disclaimers in all such redistributions of the Apple Software. Neither the name, trademarks, service marks or logos of Apple Inc. may be used to endorse or promote products derived from the Apple Software without specific prior written permission from Apple. Except as expressly stated in this notice, no other rights or licenses, express or implied, are granted by Apple herein, including but not limited to any patent rights that may be infringed by your derivative works or by other works in which the Apple Software may be incorporated. The Apple Software is provided by Apple on an "AS IS" basis. APPLE MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS. IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION, MODIFICATION AND/OR DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED AND WHETHER UNDER THEORY OF CONTRACT, TORT (INCLUDING NEGLIGENCE), STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. Copyright (C) 2009 Apple Inc. All Rights Reserved. */ #import "iTunesRSSImporter.h" #import "Song.h" #import "Category.h" #import "CategoryCache.h" #import <libxml/tree.h> // Function prototypes for SAX callbacks. This sample implements a minimal subset of SAX callbacks. // Depending on your application's needs, you might want to implement more callbacks. static void startElementSAX(void *context, const xmlChar *localname, const xmlChar *prefix, const xmlChar *URI, int nb_namespaces, const xmlChar **namespaces, int nb_attributes, int nb_defaulted, const xmlChar **attributes); static void endElementSAX(void *context, const xmlChar *localname, const xmlChar *prefix, const xmlChar *URI); static void charactersFoundSAX(void *context, const xmlChar *characters, int length); static void errorEncounteredSAX(void *context, const char *errorMessage, ...); // Forward reference. The structure is defined in full at the end of the file. static xmlSAXHandler simpleSAXHandlerStruct; // Class extension for private properties and methods. @interface iTunesRSSImporter () @property BOOL storingCharacters; @property (nonatomic, retain) NSMutableData *characterBuffer; @property BOOL done; @property BOOL parsingASong; @property NSUInteger countForCurrentBatch; @property (nonatomic, retain) Song *currentSong; @property (nonatomic, retain) NSURLConnection *rssConnection; @property (nonatomic, retain) NSDateFormatter *dateFormatter; // The autorelease pool property is assign because autorelease pools cannot be retained. @property (nonatomic, assign) NSAutoreleasePool *importPool; @end static double lookuptime = 0; @implementation iTunesRSSImporter @synthesize iTunesURL, delegate, persistentStoreCoordinator; @synthesize rssConnection, done, parsingASong, storingCharacters, currentSong, countForCurrentBatch, characterBuffer, dateFormatter, importPool; - (void)dealloc { [iTunesURL release]; [characterBuffer release]; [currentSong release]; [rssConnection release]; [dateFormatter release]; [persistentStoreCoordinator release]; [insertionContext release]; [songEntityDescription release]; [theCache release]; [super dealloc]; } - (void)main { self.importPool = [[NSAutoreleasePool alloc] init]; if (delegate && [delegate respondsToSelector:@selector(importerDidSave:)]) { [[NSNotificationCenter defaultCenter] addObserver:delegate selector:@selector(importerDidSave:) name:NSManagedObjectContextDidSaveNotification object:self.insertionContext]; } done = NO; self.dateFormatter = [[[NSDateFormatter alloc] init] autorelease]; [dateFormatter setDateStyle:NSDateFormatterLongStyle]; [dateFormatter setTimeStyle:NSDateFormatterNoStyle]; // necessary because iTunes RSS feed is not localized, so if the device region has been set to other than US // the date formatter must be set to US locale in order to parse the dates [dateFormatter setLocale:[[[NSLocale alloc] initWithLocaleIdentifier:@"US"] autorelease]]; self.characterBuffer = [NSMutableData data]; NSURLRequest *theRequest = [NSURLRequest requestWithURL:iTunesURL]; // create the connection with the request and start loading the data rssConnection = [[NSURLConnection alloc] initWithRequest:theRequest delegate:self]; // This creates a context for "push" parsing in which chunks of data that are not "well balanced" can be passed // to the context for streaming parsing. The handler structure defined above will be used for all the parsing. // The second argument, self, will be passed as user data to each of the SAX handlers. The last three arguments // are left blank to avoid creating a tree in memory. context = xmlCreatePushParserCtxt(&simpleSAXHandlerStruct, self, NULL, 0, NULL); if (rssConnection != nil) { do { [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]]; } while (!done); } // Display the total time spent finding a specific object for a relationship NSLog(@"lookup time %f", lookuptime); // Release resources used only in this thread. xmlFreeParserCtxt(context); self.characterBuffer = nil; self.dateFormatter = nil; self.rssConnection = nil; self.currentSong = nil; [theCache release]; theCache = nil; NSError *saveError = nil; NSAssert1([insertionContext save:&saveError], @"Unhandled error saving managed object context in import thread: %@", [saveError localizedDescription]); if (delegate && [delegate respondsToSelector:@selector(importerDidSave:)]) { [[NSNotificationCenter defaultCenter] removeObserver:delegate name:NSManagedObjectContextDidSaveNotification object:self.insertionContext]; } if (self.delegate != nil && [self.delegate respondsToSelector:@selector(importerDidFinishParsingData:)]) { [self.delegate importerDidFinishParsingData:self]; } [importPool release]; self.importPool = nil; } - (NSManagedObjectContext *)insertionContext { if (insertionContext == nil) { insertionContext = [[NSManagedObjectContext alloc] init]; [insertionContext setPersistentStoreCoordinator:self.persistentStoreCoordinator]; } return insertionContext; } - (void)forwardError:(NSError *)error { if (self.delegate != nil && [self.delegate respondsToSelector:@selector(importer:didFailWithError:)]) { [self.delegate importer:self didFailWithError:error]; } } - (NSEntityDescription *)songEntityDescription { if (songEntityDescription == nil) { songEntityDescription = [[NSEntityDescription entityForName:@"Song" inManagedObjectContext:self.insertionContext] retain]; } return songEntityDescription; } - (CategoryCache *)theCache { if (theCache == nil) { theCache = [[CategoryCache alloc] init]; theCache.managedObjectContext = self.insertionContext; } return theCache; } - (Song *)currentSong { if (currentSong == nil) { currentSong = [[Song alloc] initWithEntity:self.songEntityDescription insertIntoManagedObjectContext:self.insertionContext]; } return currentSong; } #pragma mark NSURLConnection Delegate methods // Forward errors to the delegate. - (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error { [self performSelectorOnMainThread:@selector(forwardError:) withObject:error waitUntilDone:NO]; // Set the condition which ends the run loop. done = YES; } // Called when a chunk of data has been downloaded. - (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data { // Process the downloaded chunk of data. xmlParseChunk(context, (const char *)[data bytes], [data length], 0); } - (void)connectionDidFinishLoading:(NSURLConnection *)connection { // Signal the context that parsing is complete by passing "1" as the last parameter. xmlParseChunk(context, NULL, 0, 1); context = NULL; // Set the condition which ends the run loop. done = YES; } #pragma mark Parsing support methods static const NSUInteger kImportBatchSize = 20; - (void)finishedCurrentSong { parsingASong = NO; self.currentSong = nil; countForCurrentBatch++; // Periodically purge the autorelease pool and save the context. The frequency of this action may need to be tuned according to the // size of the objects being parsed. The goal is to keep the autorelease pool from growing too large, but // taking this action too frequently would be wasteful and reduce performance. if (countForCurrentBatch == kImportBatchSize) { [importPool release]; self.importPool = [[NSAutoreleasePool alloc] init]; NSError *saveError = nil; NSAssert1([insertionContext save:&saveError], @"Unhandled error saving managed object context in import thread: %@", [saveError localizedDescription]); countForCurrentBatch = 0; } } /* Character data is appended to a buffer until the current element ends. */ - (void)appendCharacters:(const char *)charactersFound length:(NSInteger)length { [characterBuffer appendBytes:charactersFound length:length]; } - (NSString *)currentString { // Create a string with the character data using UTF-8 encoding. UTF-8 is the default XML data encoding. NSString *currentString = [[[NSString alloc] initWithData:characterBuffer encoding:NSUTF8StringEncoding] autorelease]; [characterBuffer setLength:0]; return currentString; } @end #pragma mark SAX Parsing Callbacks // The following constants are the XML element names and their string lengths for parsing comparison. // The lengths include the null terminator, to ensure exact matches. static const char *kName_Item = "item"; static const NSUInteger kLength_Item = 5; static const char *kName_Title = "title"; static const NSUInteger kLength_Title = 6; static const char *kName_Category = "category"; static const NSUInteger kLength_Category = 9; static const char *kName_Itms = "itms"; static const NSUInteger kLength_Itms = 5; static const char *kName_Artist = "description"; static const NSUInteger kLength_Artist = 7; static const char *kName_Album = "description"; static const NSUInteger kLength_Album = 6; static const char *kName_ReleaseDate = "releasedate"; static const NSUInteger kLength_ReleaseDate = 12; /* This callback is invoked when the importer finds the beginning of a node in the XML. For this application, out parsing needs are relatively modest - we need only match the node name. An "item" node is a record of data about a song. In that case we create a new Song object. The other nodes of interest are several of the child nodes of the Song currently being parsed. For those nodes we want to accumulate the character data in a buffer. Some of the child nodes use a namespace prefix. */ static void startElementSAX(void *parsingContext, const xmlChar *localname, const xmlChar *prefix, const xmlChar *URI, int nb_namespaces, const xmlChar **namespaces, int nb_attributes, int nb_defaulted, const xmlChar **attributes) { iTunesRSSImporter *importer = (iTunesRSSImporter *)parsingContext; // The second parameter to strncmp is the name of the element, which we known from the XML schema of the feed. // The third parameter to strncmp is the number of characters in the element name, plus 1 for the null terminator. if (prefix == NULL && !strncmp((const char *)localname, kName_Item, kLength_Item)) { importer.parsingASong = YES; } else if (importer.parsingASong && ( (prefix == NULL && (!strncmp((const char *)localname, kName_Title, kLength_Title) || !strncmp((const char *)localname, kName_Category, kLength_Category))) || ((prefix != NULL && !strncmp((const char *)prefix, kName_Itms, kLength_Itms)) && (!strncmp((const char *)localname, kName_Artist, kLength_Artist) || !strncmp((const char *)localname, kName_Album, kLength_Album) || !strncmp((const char *)localname, kName_ReleaseDate, kLength_ReleaseDate))) )) { importer.storingCharacters = YES; } } /* This callback is invoked when the parse reaches the end of a node. At that point we finish processing that node, if it is of interest to us. For "item" nodes, that means we have completed parsing a Song object. We pass the song to a method in the superclass which will eventually deliver it to the delegate. For the other nodes we care about, this means we have all the character data. The next step is to create an NSString using the buffer contents and store that with the current Song object. */ static void endElementSAX(void *parsingContext, const xmlChar *localname, const xmlChar *prefix, const xmlChar *URI) { iTunesRSSImporter *importer = (iTunesRSSImporter *)parsingContext; if (importer.parsingASong == NO) return; if (prefix == NULL) { if (!strncmp((const char *)localname, kName_Item, kLength_Item)) { [importer finishedCurrentSong]; } else if (!strncmp((const char *)localname, kName_Title, kLength_Title)) { importer.currentSong.title = importer.currentString; } else if (!strncmp((const char *)localname, kName_Category, kLength_Category)) { double before = [NSDate timeIntervalSinceReferenceDate]; Category *category = [importer.theCache categoryWithName:importer.currentString]; double delta = [NSDate timeIntervalSinceReferenceDate] - before; lookuptime += delta; importer.currentSong.category = category; } } else if (!strncmp((const char *)prefix, kName_Itms, kLength_Itms)) { if (!strncmp((const char *)localname, kName_Artist, kLength_Artist)) { NSString *string = importer.currentSong.artist; NSArray *strings = [string componentsSeparatedByString: @", "]; //importer.currentSong.artist = importer.currentString; } else if (!strncmp((const char *)localname, kName_Album, kLength_Album)) { importer.currentSong.album = importer.currentString; } else if (!strncmp((const char *)localname, kName_ReleaseDate, kLength_ReleaseDate)) { NSString *dateString = importer.currentString; importer.currentSong.releaseDate = [importer.dateFormatter dateFromString:dateString]; } } importer.storingCharacters = NO; } /* This callback is invoked when the parser encounters character data inside a node. The importer class determines how to use the character data. */ static void charactersFoundSAX(void *parsingContext, const xmlChar *characterArray, int numberOfCharacters) { iTunesRSSImporter *importer = (iTunesRSSImporter *)parsingContext; // A state variable, "storingCharacters", is set when nodes of interest begin and end. // This determines whether character data is handled or ignored. if (importer.storingCharacters == NO) return; [importer appendCharacters:(const char *)characterArray length:numberOfCharacters]; } /* A production application should include robust error handling as part of its parsing implementation. The specifics of how errors are handled depends on the application. */ static void errorEncounteredSAX(void *parsingContext, const char *errorMessage, ...) { // Handle errors as appropriate for your application. NSCAssert(NO, @"Unhandled error encountered during SAX parse."); } // The handler struct has positions for a large number of callback functions. If NULL is supplied at a given position, // that callback functionality won't be used. Refer to libxml documentation at http://www.xmlsoft.org for more information // about the SAX callbacks. static xmlSAXHandler simpleSAXHandlerStruct = { NULL, /* internalSubset */ NULL, /* isStandalone */ NULL, /* hasInternalSubset */ NULL, /* hasExternalSubset */ NULL, /* resolveEntity */ NULL, /* getEntity */ NULL, /* entityDecl */ NULL, /* notationDecl */ NULL, /* attributeDecl */ NULL, /* elementDecl */ NULL, /* unparsedEntityDecl */ NULL, /* setDocumentLocator */ NULL, /* startDocument */ NULL, /* endDocument */ NULL, /* startElement*/ NULL, /* endElement */ NULL, /* reference */ charactersFoundSAX, /* characters */ NULL, /* ignorableWhitespace */ NULL, /* processingInstruction */ NULL, /* comment */ NULL, /* warning */ errorEncounteredSAX, /* error */ NULL, /* fatalError //: unused error() get all the errors */ NULL, /* getParameterEntity */ NULL, /* cdataBlock */ NULL, /* externalSubset */ XML_SAX2_MAGIC, // NULL, startElementSAX, /* startElementNs */ endElementSAX, /* endElementNs */ NULL, /* serror */ }; Thanks.

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• Sensible Way to Pass Web Data in XML to a SQL Server Database

  - by Emtucifor

  After exploring several different ways to pass web data to a database for update purposes, I'm wondering if XML might be a good strategy. The database is currently SQL 2000. In a few months it will move to SQL 2005 and I will be able to change things if needed, but I need a SQL 2000 solution now. First of all, the database in question uses the EAV model. I know that this kind of database is generally highly frowned on, so for the purposes of this question, please just accept that this is not going to change. The current update method has the web server inserting values (that have all been converted first to their correct underlying types, then to sql_variant) to a temp table. A stored procedure is then run which expects the temp table to exist and it takes care of updating, inserting, or deleting things as needed. So far, only a single element has needed to be updated at a time. But now, there is a requirement to be able to edit multiple elements at once, and also to support hierarchical elements, each of which can have its own list of attributes. Here's some example XML I hand-typed to demonstrate what I'm thinking of. Note that in this database the Entity is Element and an ID of 0 signifies "create" aka an insert of a new item. <Elements> <Element ID="1234"> <Attr ID="221">Value</Attr> <Attr ID="225">287</Attr> <Attr ID="234"> <Element ID="99825"> <Attr ID="7">Value1</Attr> <Attr ID="8">Value2</Attr> <Attr ID="9" Action="delete" /> </Element> <Element ID="99826" Action="delete" /> <Element ID="0" Type="24"> <Attr ID="7">Value4</Attr> <Attr ID="8">Value5</Attr> <Attr ID="9">Value6</Attr> </Element> <Element ID="0" Type="24"> <Attr ID="7">Value7</Attr> <Attr ID="8">Value8</Attr> <Attr ID="9">Value9</Attr> </Element> </Attr> <Rel ID="3827" Action="delete" /> <Rel ID="2284" Role="parent"> <Element ID="3827" /> <Element ID="3829" /> <Attr ID="665">1</Attr> </Rel> <Rel ID="0" Type="23" Role="child"> <Element ID="3830" /> <Attr ID="67" </Rel> </Element> <Element ID="0" Type="87"> <Attr ID="221">Value</Attr> <Attr ID="225">569</Attr> <Attr ID="234"> <Element ID="0" Type="24"> <Attr ID="7">Value10</Attr> <Attr ID="8">Value11</Attr> <Attr ID="9">Value12</Attr> </Element> </Attr> </Element> <Element ID="1235" Action="delete" /> </Elements> Some Attributes are straight value types, such as AttrID 221. But AttrID 234 is a special "multi-value" type that can have a list of elements underneath it, and each one can have one or more values. Types only need to be presented when a new item is created, since the ElementID fully implies the type if it already exists. I'll probably support only passing in changed items (as detected by javascript). And there may be an Action="Delete" on Attr elements as well, since NULLs are treated as "unselected"--sometimes it's very important to know if a Yes/No question has intentionally been answered No or if no one's bothered to say Yes yet. There is also a different kind of data, a Relationship. At this time, those are updated through individual AJAX calls as things are edited in the UI, but I'd like to include those so that changes to relationships can be canceled (right now, once you change it, it's done). So those are really elements, too, but they are called Rel instead of Element. Relationships are implemented as ElementID1 and ElementID2, so the RelID 2284 in the XML above is in the database as: ElementID 2284 ElementID1 1234 ElementID2 3827 Having multiple children in one relationship isn't currently supported, but it would be nice later. Does this strategy and the example XML make sense? Is there a more sensible way? I'm just looking for some broad critique to help save me from going down a bad path. Any aspect that you'd like to comment on would be helpful. The web language happens to be Classic ASP, but that could change to ASP.Net at some point. A persistence engine like Linq or nHibernate is probably not acceptable right now--I just want to get this already working application enhanced without a huge amount of development time. I'll choose the answer that shows experience and has a balance of good warnings about what not to do, confirmations of what I'm planning to do, and recommendations about something else to do. I'll make it as objective as possible. P.S. I'd like to handle unicode characters as well as very long strings (10k +). UPDATE I have had this working for some time and I used the ADO Recordset Save-To-Stream trick to make creating the XML really easy. The result seems to be fairly fast, though if speed ever becomes a problem I may revisit this. In the meantime, my code works to handle any number of elements and attributes on the page at once, including updating, deleting, and creating new items all in one go. I settled on a scheme like so for all my elements: Existing data elements Example: input name e12345_a678 (element 12345, attribute 678), the input value is the value of the attribute. New elements Javascript copies a hidden template of the set of HTML elements needed for the type into the correct location on the page, increments a counter to get a new ID for this item, and prepends the number to the names of the form items. var newid = 0; function metadataAdd(reference, nameid, value) { var t = document.createElement('input'); t.setAttribute('name', nameid); t.setAttribute('id', nameid); t.setAttribute('type', 'hidden'); t.setAttribute('value', value); reference.appendChild(t); } function multiAdd(target, parentelementid, attrid, elementtypeid) { var proto = document.getElementById('a' + attrid + '_proto'); var instance = document.createElement('p'); target.parentNode.parentNode.insertBefore(instance, target.parentNode); var thisid = ++newid; instance.innerHTML = proto.innerHTML.replace(/{prefix}/g, 'n' + thisid + '_'); instance.id = 'n' + thisid; instance.className += ' new'; metadataAdd(instance, 'n' + thisid + '_p', parentelementid); metadataAdd(instance, 'n' + thisid + '_c', attrid); metadataAdd(instance, 'n' + thisid + '_t', elementtypeid); return false; } Example: Template input name _a678 becomes n1_a678 (a new element, the first one on the page, attribute 678). all attributes of this new element are tagged with the same prefix of n1. The next new item will be n2, and so on. Some hidden form inputs are created: n1_t, value is the elementtype of the element to be created n1_p, value is the parent id of the element (if it is a relationship) n1_c, value is the child id of the element (if it is a relationship) Deleting elements A hidden input is created in the form e12345_t with value set to 0. The existing controls displaying that attribute's values are disabled so they are not included in the form post. So "set type to 0" is treated as delete. With this scheme, every item on the page has a unique name and can be distinguished properly, and every action can be represented properly. When the form is posted, here's a sample of building one of the two recordsets used (classic ASP code): Set Data = Server.CreateObject("ADODB.Recordset") Data.Fields.Append "ElementID", adInteger, 4, adFldKeyColumn Data.Fields.Append "AttrID", adInteger, 4, adFldKeyColumn Data.Fields.Append "Value", adLongVarWChar, 2147483647, adFldIsNullable Or adFldMayBeNull Data.CursorLocation = adUseClient Data.CursorType = adOpenDynamic Data.Open This is the recordset for values, the other is for the elements themselves. I step through the posted form and for the element recordset use a Scripting.Dictionary populated with instances of a custom Class that has the properties I need, so that I can add the values piecemeal, since they don't always come in order. New elements are added as negative to distinguish them from regular elements (rather than requiring a separate column to indicate if it is new or addresses an existing element). I use regular expression to tear apart the form keys: "^(e|n)([0-9]{1,10})_(a|p|t|c)([0-9]{0,10})$" Then, adding an attribute looks like this. Data.AddNew ElementID.Value = DataID AttrID.Value = Integerize(Matches(0).SubMatches(3)) AttrValue.Value = Request.Form(Key) Data.Update ElementID, AttrID, and AttrValue are references to the fields of the recordset. This method is hugely faster than using Data.Fields("ElementID").Value each time. I loop through the Dictionary of element updates and ignore any that don't have all the proper information, adding the good ones to the recordset. Then I call my data-updating stored procedure like so: Set Cmd = Server.CreateObject("ADODB.Command") With Cmd Set .ActiveConnection = MyDBConn .CommandType = adCmdStoredProc .CommandText = "DataPost" .Prepared = False .Parameters.Append .CreateParameter("@ElementMetadata", adLongVarWChar, adParamInput, 2147483647, XMLFromRecordset(Element)) .Parameters.Append .CreateParameter("@ElementData", adLongVarWChar, adParamInput, 2147483647, XMLFromRecordset(Data)) End With Result.Open Cmd ' previously created recordset object with options set Here's the function that does the xml conversion: Private Function XMLFromRecordset(Recordset) Dim Stream Set Stream = Server.CreateObject("ADODB.Stream") Stream.Open Recordset.Save Stream, adPersistXML Stream.Position = 0 XMLFromRecordset = Stream.ReadText End Function Just in case the web page needs to know, the SP returns a recordset of any new elements, showing their page value and their created value (so I can see that n1 is now e12346 for example). Here are some key snippets from the stored procedure. Note this is SQL 2000 for now, though I'll be able to switch to 2005 soon: CREATE PROCEDURE [dbo].[DataPost] @ElementMetaData ntext, @ElementData ntext AS DECLARE @hdoc int --- snip --- EXEC sp_xml_preparedocument @hdoc OUTPUT, @ElementMetaData, '<xml xmlns:s="uuid:BDC6E3F0-6DA3-11d1-A2A3-00AA00C14882" xmlns:dt="uuid:C2F41010-65B3-11d1-A29F-00AA00C14882" xmlns:rs="urn:schemas-microsoft-com:rowset" xmlns:z="#RowsetSchema" />' INSERT #ElementMetadata (ElementID, ElementTypeID, ElementID1, ElementID2) SELECT * FROM OPENXML(@hdoc, '/xml/rs:data/rs:insert/z:row', 0) WITH ( ElementID int, ElementTypeID int, ElementID1 int, ElementID2 int ) ORDER BY ElementID -- orders negative items (new elements) first so they begin counting at 1 for later ID calculation EXEC sp_xml_removedocument @hdoc --- snip --- UPDATE E SET E.ElementTypeID = M.ElementTypeID FROM Element E INNER JOIN #ElementMetadata M ON E.ElementID = M.ElementID WHERE E.ElementID >= 1 AND M.ElementTypeID >= 1 The following query does the correlation of the negative new element ids to the newly inserted ones: UPDATE #ElementMetadata -- Correlate the new ElementIDs with the input rows SET NewElementID = Scope_Identity() - @@RowCount + DataID WHERE ElementID < 0 Other set-based queries do all the other work of validating that the attributes are allowed, are the correct data type, and inserting, updating, and deleting elements and attributes. I hope this brief run-down is useful to others some day! Converting ADO Recordsets to an XML stream was a huge winner for me as it saved all sorts of time and had a namespace and schema already defined that made the results come out correctly. Using a flatter XML format with 2 inputs was also much easier than sticking to some ideal about having everything in a single XML stream.

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