private inheritance - Page 83

How to make a pause before continuing method

- by user1766728

Now, I know that this has been asked, but I need to know how to do this NOT on html or anything. Heres my code, not including all of the other java files. package rtype; import java.awt.Image; import java.awt.event.KeyEvent; import java.util.ArrayList; import javax.swing.ImageIcon; public class aa { private int xd; private int yd; private int dx; private int dy; private int x; private int y; private Image image; private ArrayList missiles; private final int CRAFT_SIZE = 70; public aa() { ImageIcon ii = new ImageIcon(this.getClass().getResource("/aa.png")); image = ii.getImage(); missiles = new ArrayList(); x = 10; y = 10; xd = -14; yd = 140; } public void move() { if(y >=xd) y += dx; else if(y < xd) y += 1; if(y <=yd) y += dy; else if(y > yd) y += -1; } public int getX() { return x; } public int getY() { return y; } public Image getImage() { return image; } public ArrayList getMissiles() { return missiles; } public void keyPressed(KeyEvent e) { int key = e.getKeyCode(); if (key == KeyEvent.VK_SPACE) { fire(); } if (key == KeyEvent.VK_UP) { dy = -1; } if (key == KeyEvent.VK_DOWN) { dy = 1; } if (key == KeyEvent.VK_RIGHT) { yd++; } if (key == KeyEvent.VK_LEFT) { yd--; } if (key == KeyEvent.VK_W) { xd++; } if (key == KeyEvent.VK_S) { xd--; } } public void fire() { try{ missiles.add(new Missle(x + CRAFT_SIZE, y + CRAFT_SIZE)); }catch(Exception e){} } public void keyReleased(KeyEvent e) { int key = e.getKeyCode(); if (key == KeyEvent.VK_UP) { dy = 0; } if (key == KeyEvent.VK_DOWN) { dy = 0; } } } So, at the method, fire(), I want to make it delay between shots. HOW? sorry if this is n00bish

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Java error - not a statement, what does this mean?

- by user2898828

I am trying to get my code to create the new constructor objects which I require to create a mobile phone object. I have tried naming the constuctor fields to create the object. when I compile my code on this line this.Mobile samsungPhone = new Mobile("Samsung", 1, 2, "verizon", 3 "GPS"); I get this error: not a statement, what does this mean?? UPDATED CODE! my code: /** * to write a simple java class Mobile that models a mobile phone. * * @author (Lewis Burte-Clarke) * @version (14/10/13) */ public class Mobile { // type of phone private String phonetype; // size of screen in inches private int screensize; // menory card capacity private int memorycardcapacity; // name of present service provider private String serviceprovider; // type of contract with service provider private int typeofcontract; // camera resolution in megapixels private int cameraresolution; // the percentage of charge left on the phone private int checkcharge; // wether the phone has GPS or not private String GPS; // instance variables - replace the example below with your own private int x; // The constructor method public Mobile(String mobilephonetype, int mobilescreensize, int mobilememorycardcapacity,int mobilecameraresolution,String mobileGPS, String newserviceprovider) { this.phonetype = mobilephonetype; this.screensize = mobilescreensize; this.memorycardcapacity = mobilememorycardcapacity; this.cameraresolution = mobilecameraresolution; this.GPS = mobileGPS; this.serviceprovider = newserviceprovider; this.typeofcontract = 12; this.checkcharge = checkcharge; // you do not use this ones during instantiation,you can remove them if you do not need or assign them some default values Mobile samsungPhone = new Mobile("Samsung", 1, 2, "verizon", 3, "GPS"); 1024 = screen size; 2 = memory card capacity; 3=resolution; GPS = gps; "verizon"=service provider; typeofcontract = 12; checkcharge = checkcharge; } } // A method to display the state of the object to the screen public void displayMobileDetails() { System.out.println("phonetype: " + phonetype); System.out.println("screensize: " + screensize); System.out.println("memorycardcapacity: " + memorycardcapacity); System.out.println("cameraresolution: " + cameraresolution); System.out.println("GPS: " + GPS); System.out.println("serviceprovider: " + serviceprovider); System.out.println("typeofcontract: " + typeofcontract); } } class mymobile { public static void) { Mobile Samsung = new Mobile("Samsung", 1, 2, "verizon", 3, "GPS"); Mobile Blackberry = new Mobile("Blackberry", "3.", "4","8", "GPS"); Samsung.displayMobileDetails(); Blackberry.displayMobileDetails(); } } any answers and replies would be greatly appreciated!

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Write a tree class in Java where each level has a unique object type

- by user479576

I need to write a tree class in Java where each level has a unique object type. The way it is written below does not take advantage of generics and causes alot of duplicate code. Is there a way to write this with Generics ? public class NodeB { private String nodeValue; //private List<NodeB> childNodes; // constructors // getters/setters } public class NodeA { private String value; private List<NodeB> childNodes; // constructors // getters/setters } public class Tree { private String value; private List<NodeA> childNodes; // constructors // tree methods }

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Hibernate and mssql inner join rowcount

- by ez2sarang

I am struggling with Hibernate Criteria. My aim is to create the following request using Hibernate Criteria : select count(*) as y0_ from PInterface this_ inner join Product product2_ on this_.product_id=product2_.id where this_.product_interface_type_id=? Here is my code: @Entity @Table(name = "PInterface") public class PInterface { @Id @GeneratedValue @Column(name = "id", nullable = false, insertable = false, updatable = false) private int id; @Column(name = "product_id") private int productId; @Column(name = "product_interface_type_id") private int type; @ManyToOne(optional=false) @JoinColumn(name = "product_id", referencedColumnName = "id", insertable=false, updatable=false) private Product product; } @Entity @Table(name = "Product") public class Product { @Id @GeneratedValue @Column(name = "id", nullable = false, insertable = false, updatable = false) private int id; private String name; } //Criteria is : Object criteria = sessionFactory.getCurrentSession() .createCriteria(PInterface.class) .add(Restrictions.eq("type", 1)) .setProjection(Projections.rowCount()) .uniqueResult() ; However, the results ... select count(*) as y0_ from PInterface this_ where this_.product_interface_type_id=? Where Inner join? Thank you for help!

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Having fun with Reflection

- by Nick Harrison

I was once asked in a technical interview what I could tell them about Reflection. My response, while a little tongue in cheek was that "I can tell you it is one of my favorite topics to talk about" I did get a laugh out of that and it was a great ice breaker. Reflection may not be the answer for everything, but it often can be, or maybe even should be. I have posted in the past about my favorite CopyTo method. It can come in several forms and is often very useful. I explain it further and expand on the basic idea here The basic idea is to allow reflection to loop through the properties of two objects and synchronize the ones that are in common. I love this approach for data binding and passing data across the layers in an application. Recently I have been working on a project leveraging Data Transfer Objects to pass data through WCF calls. We won't go into how the architecture got this way, but in essence there is a partial duplicate inheritance hierarchy where there is a related Domain Object for each Data Transfer Object. The matching objects do not share a common ancestor or common interface but they will have the same properties in common. By passing the problems with this approach, let's talk about how Reflection and our friendly CopyTo could make the most of this bad situation without having to change too much. One of the problems is keeping the two sets of objects in synch. For this particular project, the DO has all of the functionality and the DTO is used to simply transfer data back and forth. Both sets of object have parallel hierarchies with the same properties being defined at the corresponding levels. So we end with BaseDO, BaseDTO, GenericDO, GenericDTO, ProcessAreaDO, ProcessAreaDTO, SpecializedProcessAreaDO, SpecializedProcessAreaDTO, TableDo, TableDto. and so on. Without using Reflection and a CopyTo function, tremendous care and effort must be made to keep the corresponding objects in synch. New properties can be added at any level in the inheritance and must be kept in synch at all subsequent layers. For this project we have come up with a clever approach of calling a base GetDo or UpdateDto making sure that the same method at each level of inheritance is called. Each level is responsible for updating the properties at that level. This is a lot of work and not keeping it in synch can create all manner of problems some of which are very difficult to track down. The other problem is the type of code that this methods tend to wind up with. You end up with code like this: Transferable dto = new Transferable(); base.GetDto(dto); dto.OfficeCode = GetDtoNullSafe(officeCode); dto.AccessIndicator = GetDtoNullSafe(accessIndicator); dto.CaseStatus = GetDtoNullSafe(caseStatus); dto.CaseStatusReason = GetDtoNullSafe(caseStatusReason); dto.LevelOfService = GetDtoNullSafe(levelOfService); dto.ReferralComments = referralComments; dto.Designation = GetDtoNullSafe(designation); dto.IsGoodCauseClaimed = GetDtoNullSafe(isGoodCauseClaimed); dto.GoodCauseClaimDate = goodCauseClaimDate; One obvious problem is that this is tedious code. It is error prone code. Adding helper functions like GetDtoNullSafe help out immensely, but there is still an easier way. We can bypass the tedious code, by pass the complex inheritance tricks, and reduce all of this to a single method in the base class. TransferObject dto = new TransferObject(); CopyTo (this, dto); return dto; In the case of this one project, such a change eliminated the need for 20% of the total code base and a whole class of unit test cases that made sure that all of the properties were in synch. The impact of such a change also needs to include the on going time savings and the improvements in quality that can arise from them. Developers who are not worried about keeping the properties in synch across mirrored object hierarchies are freed to worry about more important things like implementing business requirements.

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C# Item system design approach, should I use abstract classes, interfaces or virutals?

- by vexe

I'm working on a Resident Evil 1/2/3/0/Remake type of game. Currently I've done a big part of the inventory system (here's a link if you wanna see my inventory, pretty outdated, added a lot of features and made a lot of enhancements) Now I'm thinking about how to approach the items system, If you've played any Resident Evil game or any of its likes you should be familiar with what I'm trying to achieve. Here's a very simple category I made for the items: So you have different items, with different operations you could perform on them, there are usable items that you could use, like for example herbs and first aid kits that 'using' them would affect your health, keys to unlock doors, and equipable items that you could 'equip' like weapons. Also, you can 'combine' two items together to get new one, like for example mixing a green and red herb would give you a new type of herb, or combining a lighter with a paper, would give you a burnt paper, or ammo with a gun, would reload the gun or something. etc. You know the usual RE drill. Not all items are 'transformable', in that, for example: lighter + paper = burnt paper (it's the paper that 'transforms' to burnt paper and not the lighter, the lighter is not transformable it will remain as it is) green herb + red herb = newHerb1 (both herbs will vanish and transform to this new type of herb) ammo + gun = reload gun (ammo state will remain as it is, it won't change but it will just decrease, nothing will happen to the gun it just gets reloaded) Also a key note to remember is that you can't just combine items randomly, each item has a 'mating' item(s). So to sum up, different items, and different operations on them. The question is, how to approach this, design-wise? I've been learning about interfaces, but it just doesn't quite get into my head, I mean, why not just use classes with the good old inheritance? I know the technical details of interfaces and that the cool thing about them is that they don't require an inheritance chain, but I just can't see how to use them properly, that is, if they were the right thing to use here. So should I go with just classes and inheritance? just like in the tree I showed you? or should I think more about how to use interfaces? (IUsable, IEquipable, ITransformable) - why not just use classes UsableItem, Equipable item, TransformableItem? I want something that won't give me headaches in the long run, something resilient/flexible to future changes. I'm OK using classes, but I smell something better here. The way I'm thinking is to possibly use both inheritance and interfaces, so that you have a branch like this: item - equipable - weapon. but then again, the weapon has methods like 'reload' 'examine' 'equip' some of them 'combine' so I'm thinking to make weapon implement ICombinable?... not all items get used the same way, using herbs will increase your health, using a key will open a door, so IUsable maybe? Should I use a big database (XML for example) for all the items, items names, mates, nRowsReq, nColsReq, etc? Thanks so much for your answers in advanced, note that demo 3 is coming after I'm done with items :D

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Mac OS X 10.8 VPN Server: Bypass VPN for LAN traffic (routing LAN traffic to secondary connection)

- by Dan Robson

I have somewhat of an odd setup for a VPN server with OS X Mountain Lion. It's essentially being used as a bridge to bypass my company's firewall to our extranet connection - certain things our team needs to do require unfettered access to the outside, and changing IT policies to allow traffic through the main firewall is just not an option. The extranet connection is provided through a Wireless-N router (let's call it Wi-Fi X). My Mac Mini server is configured with the connection to this router as the primary connection, thus unfettered access to the internet via the router. Connections to this device on the immediate subnet are possible through the LAN port, but outside the subnet things are less reliable. I was able to configure the VPN server to provide IP addresses to clients in the 192.168.11.150-192.168.11.200 range using both PPTP and L2TP, and I'm able to connect to the extranet through the VPN using the standard Mac OS X VPN client in System Preferences, however unsurprisingly, a local address (let's call it internal.company.com) returns nothing. I tried to bypass the limitation of the VPN Server by setting up Routes in the VPN settings. Our company uses 13.x.x.x for all internal traffic, instead of 10.x.x.x, so the routing table looked something like this: IP Address ---------- Subnet Mask ---------- Configuration 0.0.0.0 248.0.0.0 Private 8.0.0.0 252.0.0.0 Private 12.0.0.0 255.0.0.0 Private 13.0.0.0 255.0.0.0 Public 14.0.0.0 254.0.0.0 Private 16.0.0.0 240.0.0.0 Private 32.0.0.0 224.0.0.0 Private 64.0.0.0 192.0.0.0 Private 128.0.0.0 128.0.0.0 Private I was under the impression that if nothing was entered here, all traffic was routed through the VPN. With something entered, only traffic specifically marked to go through the VPN would go through the VPN, and all other traffic would be up to the client to access using its own default connection. This is why I had to specifically mark every subnet except 13.x.x.x as Private. My suspicion is that since I can't reach the VPN server from outside the local subnet, it's not making a connection to the main DNS server and thus can't be reached on the larger network. I'm thinking that entering hostnames like internal.company.com aren't kicked back to the client to resolve, because the server has no idea that the IP address falls in the public range, since I suspect (probably should ping test it but don't have access to it right now) that it can't reach the DNS server to find out anything about that hostname. It seems to me that all my options for resolving this all boil down to the same type of solution: Figure out how to reach the DNS with the secondary connection on the server. I'm thinking that if I'm able to do [something] to get my server to recognize that it should also check my local gateway (let's say Server IP == 13.100.100.50 and Gateway IP == 13.100.100.1). From there Gateway IP can tell me to go find DNS Server at 13.1.1.1 and give me information about my internal network. I'm very confused about this path -- really not sure if I'm even making sense. I thought about trying to do this client side, but that doesn't make sense either, since that would add time to each and every client side setup. Plus, it just seems more logical to solve it on the server - I could either get rid of my routing table altogether or keep it - I think the only difference would be that internal traffic would also go through the server - probably an unnecessary burden on it. Any help out there? Or am I in over my head? Forward proxy or transparent proxy is also an option for me, although I have no idea how to set either of those up. (I know, Google is my friend.)

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How can I resolve Hibernate 3's ConstraintViolationException when updating a Persistent Entity's Col

- by Tim Visher

I'm trying to discover why two nearly identical class sets are behaving different from Hibernate 3's perspective. I'm fairly new to Hibernate in general and I'm hoping I'm missing something fairly obvious about the mappings or timing issues or something along those lines but I spent the whole day yesterday staring at the two sets and any differences that would lead to one being able to be persisted and the other not completely escaped me. I appologize in advance for the length of this question but it all hinges around some pretty specific implementation details. I have the following class mapped with Annotations and managed by Hibernate 3.? (if the specific specific version turns out to be pertinent, I'll figure out what it is). Java version is 1.6. ... @Embeddable public class JobStateChange implements Comparable<JobStateChange> { @Temporal(TemporalType.TIMESTAMP) @Column(nullable = false) private Date date; @Enumerated(EnumType.STRING) @Column(nullable = false, length = JobState.FIELD_LENGTH) private JobState state; @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "acting_user_id", nullable = false) private User actingUser; public JobStateChange() { } @Override public int compareTo(final JobStateChange o) { return this.date.compareTo(o.date); } @Override public boolean equals(final Object obj) { if (this == obj) { return true; } else if (!(obj instanceof JobStateChange)) { return false; } JobStateChange candidate = (JobStateChange) obj; return this.state == candidate.state && this.actingUser.equals(candidate.getUser()) && this.date.equals(candidate.getDate()); } @Override public int hashCode() { return this.state.hashCode() + this.actingUser.hashCode() + this.date.hashCode(); } } It is mapped as a Hibernate CollectionOfElements in the class Job as follows: ... @Entity @Table( name = "job", uniqueConstraints = { @UniqueConstraint( columnNames = { "agency", //Job Name "payment_type", //Job Name "payment_file", //Job Name "date_of_payment", "payment_control_number", "truck_number" }) }) public class Job implements Serializable { private static final long serialVersionUID = -1131729422634638834L; ... @org.hibernate.annotations.CollectionOfElements @JoinTable(name = "job_state", joinColumns = @JoinColumn(name = "job_id")) @Sort(type = SortType.NATURAL) private final SortedSet<JobStateChange> stateChanges = new TreeSet<JobStateChange>(); ... public void advanceState( final User actor, final Date date) { JobState nextState; LOGGER.debug("Current state of {} is {}.", this, this.getCurrentState()); if (null == this.currentState) { nextState = JobState.BEGINNING; } else { if (!this.isAdvanceable()) { throw new IllegalAdvancementException(this.currentState.illegalAdvancementStateMessage); } if (this.currentState.isDivergent()) { nextState = this.currentState.getNextState(this); } else { nextState = this.currentState.getNextState(); } } JobStateChange stateChange = new JobStateChange(nextState, actor, date); this.setCurrentState(stateChange.getState()); this.stateChanges.add(stateChange); LOGGER.debug("Advanced {} to {}", this, this.getCurrentState()); } private void setCurrentState(final JobState jobState) { this.currentState = jobState; } boolean isAdvanceable() { return this.getCurrentState().isAdvanceable(this); } ... @Override public boolean equals(final Object obj) { if (obj == this) { return true; } else if (!(obj instanceof Job)) { return false; } Job otherJob = (Job) obj; return this.getName().equals(otherJob.getName()) && this.getDateOfPayment().equals(otherJob.getDateOfPayment()) && this.getPaymentControlNumber().equals(otherJob.getPaymentControlNumber()) && this.getTruckNumber().equals(otherJob.getTruckNumber()); } @Override public int hashCode() { return this.getName().hashCode() + this.getDateOfPayment().hashCode() + this.getPaymentControlNumber().hashCode() + this.getTruckNumber().hashCode(); } ... } The purpose of JobStateChange is to record when the Job moves through a series of State Changes that are outline in JobState as enums which know about advancement and decrement rules. The interface used to advance Jobs through a series of states is to call Job.advanceState() with a Date and a User. If the Job is advanceable according to rules coded in the enum, then a new StateChange is added to the SortedSet and everyone's happy. If not, an IllegalAdvancementException is thrown. The DDL this generates is as follows: ... drop table job; drop table job_state; ... create table job ( id bigint generated by default as identity, current_state varchar(25), date_of_payment date not null, beginningCheckNumber varchar(8) not null, item_count integer, agency varchar(10) not null, payment_file varchar(25) not null, payment_type varchar(25) not null, endingCheckNumber varchar(8) not null, payment_control_number varchar(4) not null, truck_number varchar(255) not null, wrapping_system_type varchar(15) not null, printer_id bigint, primary key (id), unique (agency, payment_type, payment_file, date_of_payment, payment_control_number, truck_number) ); create table job_state ( job_id bigint not null, acting_user_id bigint not null, date timestamp not null, state varchar(25) not null, primary key (job_id, acting_user_id, date, state) ); ... alter table job add constraint FK19BBD12FB9D70 foreign key (printer_id) references printer; alter table job_state add constraint FK57C2418FED1F0D21 foreign key (acting_user_id) references app_user; alter table job_state add constraint FK57C2418FABE090B3 foreign key (job_id) references job; ... The database is seeded with the following data prior to running tests ... insert into job (id, agency, payment_type, payment_file, payment_control_number, date_of_payment, beginningCheckNumber, endingCheckNumber, item_count, current_state, printer_id, wrapping_system_type, truck_number) values (-3, 'RRB', 'Monthly', 'Monthly','4501','1998-12-01 08:31:16' , '00000001','00040000', 40000, 'UNASSIGNED', null, 'KERN', '02'); insert into job_state (job_id, acting_user_id, date, state) values (-3, -1, '1998-11-30 08:31:17', 'UNASSIGNED'); ... After the database schema is automatically generated and rebuilt by the Hibernate tool. The following test runs fine up until the call to Session.flush() ... @ContextConfiguration(locations = { "/applicationContext-data.xml", "/applicationContext-service.xml" }) public class JobDaoIntegrationTest extends AbstractTransactionalJUnit4SpringContextTests { @Autowired private JobDao jobDao; @Autowired private SessionFactory sessionFactory; @Autowired private UserService userService; @Autowired private PrinterService printerService; ... @Test public void saveJob_JobAdvancedToAssigned_AllExpectedStateChanges() { //Get an unassigned Job Job job = this.jobDao.getJob(-3L); assertEquals(JobState.UNASSIGNED, job.getCurrentState()); Date advancedToUnassigned = new GregorianCalendar(1998, 10, 30, 8, 31, 17).getTime(); assertEquals(advancedToUnassigned, job.getStateChange(JobState.UNASSIGNED).getDate()); //Satisfy advancement constraints and advance job.setPrinter(this.printerService.getPrinter(-1L)); Date advancedToAssigned = new Date(); job.advanceState( this.userService.getUserByUsername("admin"), advancedToAssigned); assertEquals(JobState.ASSIGNED, job.getCurrentState()); assertEquals(advancedToUnassigned, job.getStateChange(JobState.UNASSIGNED).getDate()); assertEquals(advancedToAssigned, job.getStateChange(JobState.ASSIGNED).getDate()); //Persist to DB this.sessionFactory.getCurrentSession().flush(); ... } ... } The error thrown is SQLCODE=-803, SQLSTATE=23505: could not insert collection rows: [jaci.model.job.Job.stateChanges#-3] org.hibernate.exception.ConstraintViolationException: could not insert collection rows: [jaci.model.job.Job.stateChanges#-3] at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:94) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) at org.hibernate.persister.collection.AbstractCollectionPersister.insertRows(AbstractCollectionPersister.java:1416) at org.hibernate.action.CollectionUpdateAction.execute(CollectionUpdateAction.java:86) at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:263) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:170) at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321) at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50) at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027) at jaci.dao.JobDaoIntegrationTest.saveJob_JobAdvancedToAssigned_AllExpectedStateChanges(JobDaoIntegrationTest.java:98) at org.springframework.test.context.junit4.SpringTestMethod.invoke(SpringTestMethod.java:160) at org.springframework.test.context.junit4.SpringMethodRoadie.runTestMethod(SpringMethodRoadie.java:233) at org.springframework.test.context.junit4.SpringMethodRoadie$RunBeforesThenTestThenAfters.run(SpringMethodRoadie.java:333) at org.springframework.test.context.junit4.SpringMethodRoadie.runWithRepetitions(SpringMethodRoadie.java:217) at org.springframework.test.context.junit4.SpringMethodRoadie.runTest(SpringMethodRoadie.java:197) at org.springframework.test.context.junit4.SpringMethodRoadie.run(SpringMethodRoadie.java:143) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.invokeTestMethod(SpringJUnit4ClassRunner.java:160) at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:97) Caused by: com.ibm.db2.jcc.b.lm: DB2 SQL Error: SQLCODE=-803, SQLSTATE=23505, SQLERRMC=1;ACI_APP.JOB_STATE, DRIVER=3.50.152 at com.ibm.db2.jcc.b.wc.a(wc.java:575) at com.ibm.db2.jcc.b.wc.a(wc.java:57) at com.ibm.db2.jcc.b.wc.a(wc.java:126) at com.ibm.db2.jcc.b.tk.b(tk.java:1593) at com.ibm.db2.jcc.b.tk.c(tk.java:1576) at com.ibm.db2.jcc.t4.db.k(db.java:353) at com.ibm.db2.jcc.t4.db.a(db.java:59) at com.ibm.db2.jcc.t4.t.a(t.java:50) at com.ibm.db2.jcc.t4.tb.b(tb.java:200) at com.ibm.db2.jcc.b.uk.Gb(uk.java:2355) at com.ibm.db2.jcc.b.uk.e(uk.java:3129) at com.ibm.db2.jcc.b.uk.zb(uk.java:568) at com.ibm.db2.jcc.b.uk.executeUpdate(uk.java:551) at org.hibernate.jdbc.NonBatchingBatcher.addToBatch(NonBatchingBatcher.java:46) at org.hibernate.persister.collection.AbstractCollectionPersister.insertRows(AbstractCollectionPersister.java:1389) Therein lies my problem… A nearly identical Class set (in fact, so identical that I've been chomping at the bit to make it a single class that serves both business entities) runs absolutely fine. It is identical except for name. Instead of Job it's Web. Instead of JobStateChange it's WebStateChange. Instead of JobState it's WebState. Both Job and Web's SortedSet of StateChanges are mapped as a Hibernate CollectionOfElements. Both are @Embeddable. Both are SortType.Natural. Both are backed by an Enumeration with some advancement rules in it. And yet when a nearly identical test is run for Web, no issue is discovered and the data flushes fine. For the sake of brevity I won't include all of the Web classes here, but I will include the test and if anyone wants to see the actual sources, I'll include them (just leave a comment). The data seed: insert into web (id, stock_type, pallet, pallet_id, date_received, first_icn, last_icn, shipment_id, current_state) values (-1, 'PF', '0011', 'A', '2008-12-31 08:30:02', '000000001', '000080000', -1, 'UNSTAGED'); insert into web_state (web_id, date, state, acting_user_id) values (-1, '2008-12-31 08:30:03', 'UNSTAGED', -1); The test: ... @ContextConfiguration(locations = { "/applicationContext-data.xml", "/applicationContext-service.xml" }) public class WebDaoIntegrationTest extends AbstractTransactionalJUnit4SpringContextTests { @Autowired private WebDao webDao; @Autowired private UserService userService; @Autowired private SessionFactory sessionFactory; ... @Test public void saveWeb_WebAdvancedToNewState_AllExpectedStateChanges() { Web web = this.webDao.getWeb(-1L); Date advancedToUnstaged = new GregorianCalendar(2008, 11, 31, 8, 30, 3).getTime(); assertEquals(WebState.UNSTAGED, web.getCurrentState()); assertEquals(advancedToUnstaged, web.getState(WebState.UNSTAGED).getDate()); Date advancedToStaged = new Date(); web.advanceState( this.userService.getUserByUsername("admin"), advancedToStaged); this.sessionFactory.getCurrentSession().flush(); web = this.webDao.getWeb(web.getId()); assertEquals( "Web should have moved to STAGED State.", WebState.STAGED, web.getCurrentState()); assertEquals(advancedToUnstaged, web.getState(WebState.UNSTAGED).getDate()); assertEquals(advancedToStaged, web.getState(WebState.STAGED).getDate()); assertNotNull(web.getState(WebState.UNSTAGED)); assertNotNull(web.getState(WebState.STAGED)); } ... } As you can see, I assert that the Web was reconstituted the way I expect, I advance it, flush it to the DB, and then re-get it and verify that the states are as I expect. Everything works perfectly. Not so with Job. A possibly pertinent detail: the reconstitution code works fine if I cease to map JobStateChange.data as a TIMESTAMP and instead as a DATE, and ensure that all of the StateChanges always occur on different Dates. The problem is that this particular business entity can go through many state changes in a single day and so it needs to be sorted by time stamp rather than by date. If I don't do this then I can't sort the StateChanges correctly. That being said, WebStateChange.date is also mapped as a TIMESTAMP and so I again remain absolutely befuddled as to where this error is arising from. I tried to do a fairly thorough job of giving all of the technical details of the implementation but as this particular question is very implementation specific, if I missed anything just let me know in the comments and I'll include it. Thanks so much for your help! UPDATE: Since it turns out to be important to the solution of my problem, I have to include the pertinent bits of the WebStateChange class as well. ... @Embeddable public class WebStateChange implements Comparable<WebStateChange> { @Temporal(TemporalType.TIMESTAMP) @Column(nullable = false) private Date date; @Enumerated(EnumType.STRING) @Column(nullable = false, length = WebState.FIELD_LENGTH) private WebState state; @ManyToOne(fetch = FetchType.LAZY) @JoinColumn(name = "acting_user_id", nullable = false) private User actingUser; ... WebStateChange( final WebState state, final User actingUser, final Date date) { ExceptionUtils.illegalNullArgs(state, actingUser, date); this.state = state; this.actingUser = actingUser; this.date = new Date(date.getTime()); } @Override public int compareTo(final WebStateChange otherStateChange) { return this.date.compareTo(otherStateChange.date); } @Override public boolean equals(final Object candidate) { if (this == candidate) { return true; } else if (!(candidate instanceof WebStateChange)) { return false; } WebStateChange candidateWebState = (WebStateChange) candidate; return this.getState() == candidateWebState.getState() && this.getUser().equals(candidateWebState.getUser()) && this.getDate().equals(candidateWebState.getDate()); } @Override public int hashCode() { return this.getState().hashCode() + this.getUser().hashCode() + this.getDate().hashCode(); } ... }

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Sent Item code in java

- by Farhan Khan

I need urgent help, if any one can resolve my issue it will be very highly appriciated. I have create a SMS composer on jAVA netbians its on urdu language. the probelm is its not saving sent sms on Sent items.. i have tried my best to make the code but failed. Tomorrow is my last day to present the code on university please help me please below is the code that i have made till now. Please any one.... /* * To change this template, choose Tools | Templates * and open the template in the editor. */ package newSms; import javax.microedition.io.Connector; import javax.microedition.midlet.*; import javax.microedition.lcdui.*; import javax.wireless.messaging.MessageConnection; import javax.wireless.messaging.TextMessage; import org.netbeans.microedition.util.SimpleCancellableTask; /** * @author AHTISHAM */ public class composeurdu extends MIDlet implements CommandListener, ItemCommandListener, ItemStateListener { private boolean midletPaused = false; private boolean isUrdu; String numb=" "; Alert alert; //<editor-fold defaultstate="collapsed" desc=" Generated Fields ">//GEN-BEGIN:|fields|0| private Form form; private TextField number; private TextField textUrdu; private StringItem stringItem; private StringItem send; private Command exit; private Command sendMesg; private Command add; private Command urdu; private Command select; private SimpleCancellableTask task; //</editor-fold>//GEN-END:|fields|0| MessageConnection clientConn; private Display display; public composeurdu() { display = Display.getDisplay(this); } private void showMessage(){ display=Display.getDisplay(this); //numb=number.getString(); if(number.getString().length()==0 || textUrdu.getString().length()==0){ Alert alert=new Alert("error "); alert.setString(" Enter phone number"); alert.setTimeout(5000); display.setCurrent(alert); } else if(number.getString().length()>11){ Alert alert=new Alert("error "); alert.setString("invalid number"); alert.setTimeout(5000); display.setCurrent(alert); } else{ Alert alert=new Alert("error "); alert.setString("success"); alert.setTimeout(5000); display.setCurrent(alert); } } void showMessage(String message, Displayable displayable) { Alert alert = new Alert(""); alert.setTitle("Error"); alert.setString(message); alert.setType(AlertType.ERROR); alert.setTimeout(5000); display.setCurrent(alert, displayable); } //<editor-fold defaultstate="collapsed" desc=" Generated Methods ">//GEN-BEGIN:|methods|0| //</editor-fold>//GEN-END:|methods|0| //<editor-fold defaultstate="collapsed" desc=" Generated Method: initialize ">//GEN-BEGIN:|0-initialize|0|0-preInitialize /** * Initializes the application. It is called only once when the MIDlet is * started. The method is called before the * <code>startMIDlet</code> method. */ private void initialize() {//GEN-END:|0-initialize|0|0-preInitialize // write pre-initialize user code here //GEN-LINE:|0-initialize|1|0-postInitialize // write post-initialize user code here }//GEN-BEGIN:|0-initialize|2| //</editor-fold>//GEN-END:|0-initialize|2| //<editor-fold defaultstate="collapsed" desc=" Generated Method: startMIDlet ">//GEN-BEGIN:|3-startMIDlet|0|3-preAction /** * Performs an action assigned to the Mobile Device - MIDlet Started point. */ public void startMIDlet() {//GEN-END:|3-startMIDlet|0|3-preAction // write pre-action user code here switchDisplayable(null, getForm());//GEN-LINE:|3-startMIDlet|1|3-postAction // write post-action user code here form.setCommandListener(this); form.setItemStateListener(this); }//GEN-BEGIN:|3-startMIDlet|2| //</editor-fold>//GEN-END:|3-startMIDlet|2| //<editor-fold defaultstate="collapsed" desc=" Generated Method: resumeMIDlet ">//GEN-BEGIN:|4-resumeMIDlet|0|4-preAction /** * Performs an action assigned to the Mobile Device - MIDlet Resumed point. */ public void resumeMIDlet() {//GEN-END:|4-resumeMIDlet|0|4-preAction // write pre-action user code here //GEN-LINE:|4-resumeMIDlet|1|4-postAction // write post-action user code here }//GEN-BEGIN:|4-resumeMIDlet|2| //</editor-fold>//GEN-END:|4-resumeMIDlet|2| //<editor-fold defaultstate="collapsed" desc=" Generated Method: switchDisplayable ">//GEN-BEGIN:|5-switchDisplayable|0|5-preSwitch /** * Switches a current displayable in a display. The * <code>display</code> instance is taken from * <code>getDisplay</code> method. This method is used by all actions in the * design for switching displayable. * * @param alert the Alert which is temporarily set to the display; if * <code>null</code>, then * <code>nextDisplayable</code> is set immediately * @param nextDisplayable the Displayable to be set */ public void switchDisplayable(Alert alert, Displayable nextDisplayable) {//GEN-END:|5-switchDisplayable|0|5-preSwitch // write pre-switch user code here Display display = getDisplay();//GEN-BEGIN:|5-switchDisplayable|1|5-postSwitch if (alert == null) { display.setCurrent(nextDisplayable); } else { display.setCurrent(alert, nextDisplayable); }//GEN-END:|5-switchDisplayable|1|5-postSwitch // write post-switch user code here }//GEN-BEGIN:|5-switchDisplayable|2| //</editor-fold>//GEN-END:|5-switchDisplayable|2| //<editor-fold defaultstate="collapsed" desc=" Generated Method: commandAction for Displayables ">//GEN-BEGIN:|7-commandAction|0|7-preCommandAction /** * Called by a system to indicated that a command has been invoked on a * particular displayable. * * @param command the Command that was invoked * @param displayable the Displayable where the command was invoked */ public void commandAction(Command command, Displayable displayable) {//GEN-END:|7-commandAction|0|7-preCommandAction // write pre-action user code here if (displayable == form) {//GEN-BEGIN:|7-commandAction|1|16-preAction if (command == exit) {//GEN-END:|7-commandAction|1|16-preAction // write pre-action user code here exitMIDlet();//GEN-LINE:|7-commandAction|2|16-postAction // write post-action user code here } else if (command == sendMesg) {//GEN-LINE:|7-commandAction|3|18-preAction // write pre-action user code here String mno=number.getString(); String msg=textUrdu.getString(); if(mno.equals("")) { alert = new Alert("Alert"); alert.setString("Enter Mobile Number!!!"); alert.setTimeout(2000); display.setCurrent(alert); } else { try { clientConn=(MessageConnection)Connector.open("sms://"+mno); } catch(Exception e) { alert = new Alert("Alert"); alert.setString("Unable to connect to Station because of network problem"); alert.setTimeout(2000); display.setCurrent(alert); } try { TextMessage textmessage = (TextMessage) clientConn.newMessage(MessageConnection.TEXT_MESSAGE); textmessage.setAddress("sms://"+mno); textmessage.setPayloadText(msg); clientConn.send(textmessage); } catch(Exception e) { Alert alert=new Alert("Alert","",null,AlertType.INFO); alert.setTimeout(Alert.FOREVER); alert.setString("Unable to send"); display.setCurrent(alert); } } //GEN-LINE:|7-commandAction|4|18-postAction // write post-action user code here }//GEN-BEGIN:|7-commandAction|5|7-postCommandAction }//GEN-END:|7-commandAction|5|7-postCommandAction // write post-action user code here }//GEN-BEGIN:|7-commandAction|6| //</editor-fold>//GEN-END:|7-commandAction|6| //<editor-fold defaultstate="collapsed" desc=" Generated Method: commandAction for Items ">//GEN-BEGIN:|8-itemCommandAction|0|8-preItemCommandAction /** * Called by a system to indicated that a command has been invoked on a * particular item. * * @param command the Command that was invoked * @param displayable the Item where the command was invoked */ public void commandAction(Command command, Item item) {//GEN-END:|8-itemCommandAction|0|8-preItemCommandAction // write pre-action user code here if (item == number) {//GEN-BEGIN:|8-itemCommandAction|1|21-preAction if (command == add) {//GEN-END:|8-itemCommandAction|1|21-preAction // write pre-action user code here //GEN-LINE:|8-itemCommandAction|2|21-postAction // write post-action user code here }//GEN-BEGIN:|8-itemCommandAction|3|28-preAction } else if (item == send) { if (command == select) {//GEN-END:|8-itemCommandAction|3|28-preAction // write pre-action user code here //GEN-LINE:|8-itemCommandAction|4|28-postAction // write post-action user code here }//GEN-BEGIN:|8-itemCommandAction|5|24-preAction } else if (item == textUrdu) { if (command == urdu) {//GEN-END:|8-itemCommandAction|5|24-preAction // write pre-action user code here if (isUrdu) isUrdu = false; else { isUrdu = true; TextField tf = (TextField)item; } //GEN-LINE:|8-itemCommandAction|6|24-postAction // write post-action user code here }//GEN-BEGIN:|8-itemCommandAction|7|8-postItemCommandAction }//GEN-END:|8-itemCommandAction|7|8-postItemCommandAction // write post-action user code here }//GEN-BEGIN:|8-itemCommandAction|8| //</editor-fold>//GEN-END:|8-itemCommandAction|8| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: form ">//GEN-BEGIN:|14-getter|0|14-preInit /** * Returns an initialized instance of form component. * * @return the initialized component instance */ public Form getForm() { if (form == null) {//GEN-END:|14-getter|0|14-preInit // write pre-init user code here form = new Form("form", new Item[]{getNumber(), getTextUrdu(), getStringItem(), getSend()});//GEN-BEGIN:|14-getter|1|14-postInit form.addCommand(getExit()); form.addCommand(getSendMesg()); form.setCommandListener(this);//GEN-END:|14-getter|1|14-postInit // write post-init user code here form.setItemStateListener(this); // form.setCommandListener(this); }//GEN-BEGIN:|14-getter|2| return form; } //</editor-fold>//GEN-END:|14-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: number ">//GEN-BEGIN:|19-getter|0|19-preInit /** * Returns an initialized instance of number component. * * @return the initialized component instance */ public TextField getNumber() { if (number == null) {//GEN-END:|19-getter|0|19-preInit // write pre-init user code here number = new TextField("Number ", null, 11, TextField.PHONENUMBER);//GEN-BEGIN:|19-getter|1|19-postInit number.addCommand(getAdd()); number.setItemCommandListener(this); number.setDefaultCommand(getAdd());//GEN-END:|19-getter|1|19-postInit // write post-init user code here }//GEN-BEGIN:|19-getter|2| return number; } //</editor-fold>//GEN-END:|19-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: textUrdu ">//GEN-BEGIN:|22-getter|0|22-preInit /** * Returns an initialized instance of textUrdu component. * * @return the initialized component instance */ public TextField getTextUrdu() { if (textUrdu == null) {//GEN-END:|22-getter|0|22-preInit // write pre-init user code here textUrdu = new TextField("Message", null, 2000, TextField.ANY);//GEN-BEGIN:|22-getter|1|22-postInit textUrdu.addCommand(getUrdu()); textUrdu.setItemCommandListener(this);//GEN-END:|22-getter|1|22-postInit // write post-init user code here }//GEN-BEGIN:|22-getter|2| return textUrdu; } //</editor-fold>//GEN-END:|22-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: exit ">//GEN-BEGIN:|15-getter|0|15-preInit /** * Returns an initialized instance of exit component. * * @return the initialized component instance */ public Command getExit() { if (exit == null) {//GEN-END:|15-getter|0|15-preInit // write pre-init user code here exit = new Command("Exit", Command.EXIT, 0);//GEN-LINE:|15-getter|1|15-postInit // write post-init user code here }//GEN-BEGIN:|15-getter|2| return exit; } //</editor-fold>//GEN-END:|15-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: sendMesg ">//GEN-BEGIN:|17-getter|0|17-preInit /** * Returns an initialized instance of sendMesg component. * * @return the initialized component instance */ public Command getSendMesg() { if (sendMesg == null) {//GEN-END:|17-getter|0|17-preInit // write pre-init user code here sendMesg = new Command("send", Command.OK, 0);//GEN-LINE:|17-getter|1|17-postInit // write post-init user code here }//GEN-BEGIN:|17-getter|2| return sendMesg; } //</editor-fold>//GEN-END:|17-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: add ">//GEN-BEGIN:|20-getter|0|20-preInit /** * Returns an initialized instance of add component. * * @return the initialized component instance */ public Command getAdd() { if (add == null) {//GEN-END:|20-getter|0|20-preInit // write pre-init user code here add = new Command("add", Command.OK, 0);//GEN-LINE:|20-getter|1|20-postInit // write post-init user code here }//GEN-BEGIN:|20-getter|2| return add; } //</editor-fold>//GEN-END:|20-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: urdu ">//GEN-BEGIN:|23-getter|0|23-preInit /** * Returns an initialized instance of urdu component. * * @return the initialized component instance */ public Command getUrdu() { if (urdu == null) {//GEN-END:|23-getter|0|23-preInit // write pre-init user code here urdu = new Command("urdu", Command.OK, 0);//GEN-LINE:|23-getter|1|23-postInit // write post-init user code here }//GEN-BEGIN:|23-getter|2| return urdu; } //</editor-fold>//GEN-END:|23-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: stringItem ">//GEN-BEGIN:|25-getter|0|25-preInit /** * Returns an initialized instance of stringItem component. * * @return the initialized component instance */ public StringItem getStringItem() { if (stringItem == null) {//GEN-END:|25-getter|0|25-preInit // write pre-init user code here stringItem = new StringItem("string", null);//GEN-LINE:|25-getter|1|25-postInit // write post-init user code here }//GEN-BEGIN:|25-getter|2| return stringItem; } //</editor-fold>//GEN-END:|25-getter|2| //</editor-fold> //<editor-fold defaultstate="collapsed" desc=" Generated Getter: send ">//GEN-BEGIN:|26-getter|0|26-preInit /** * Returns an initialized instance of send component. * * @return the initialized component instance */ public StringItem getSend() { if (send == null) {//GEN-END:|26-getter|0|26-preInit // write pre-init user code here send = new StringItem("", "send", Item.BUTTON);//GEN-BEGIN:|26-getter|1|26-postInit send.addCommand(getSelect()); send.setItemCommandListener(this); send.setDefaultCommand(getSelect());//GEN-END:|26-getter|1|26-postInit // write post-init user code here }//GEN-BEGIN:|26-getter|2| return send; } //</editor-fold>//GEN-END:|26-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: select ">//GEN-BEGIN:|27-getter|0|27-preInit /** * Returns an initialized instance of select component. * * @return the initialized component instance */ public Command getSelect() { if (select == null) {//GEN-END:|27-getter|0|27-preInit // write pre-init user code here select = new Command("select", Command.OK, 0);//GEN-LINE:|27-getter|1|27-postInit // write post-init user code here }//GEN-BEGIN:|27-getter|2| return select; } //</editor-fold>//GEN-END:|27-getter|2| //<editor-fold defaultstate="collapsed" desc=" Generated Getter: task ">//GEN-BEGIN:|40-getter|0|40-preInit /** * Returns an initialized instance of task component. * * @return the initialized component instance */ public SimpleCancellableTask getTask() { if (task == null) {//GEN-END:|40-getter|0|40-preInit // write pre-init user code here task = new SimpleCancellableTask();//GEN-BEGIN:|40-getter|1|40-execute task.setExecutable(new org.netbeans.microedition.util.Executable() { public void execute() throws Exception {//GEN-END:|40-getter|1|40-execute // write task-execution user code here }//GEN-BEGIN:|40-getter|2|40-postInit });//GEN-END:|40-getter|2|40-postInit // write post-init user code here }//GEN-BEGIN:|40-getter|3| return task; } //</editor-fold>//GEN-END:|40-getter|3| /** * Returns a display instance. * @return the display instance. */ public Display getDisplay () { return Display.getDisplay(this); } /** * Exits MIDlet. */ public void exitMIDlet() { switchDisplayable (null, null); destroyApp(true); notifyDestroyed(); } /** * Called when MIDlet is started. * Checks whether the MIDlet have been already started and initialize/starts or resumes the MIDlet. */ public void startApp() { startMIDlet(); display.setCurrent(form); } /** * Called when MIDlet is paused. */ public void pauseApp() { midletPaused = true; } /** * Called to signal the MIDlet to terminate. * @param unconditional if true, then the MIDlet has to be unconditionally terminated and all resources has to be released. */ public void destroyApp(boolean unconditional) { } public void itemStateChanged(Item item) { if (item == textUrdu) { if (isUrdu) { stringItem.setText("urdu"); TextField tf = (TextField)item; String s = tf.getString(); char ch = s.charAt(s.length() - 1); s = s.substring(0, s.length() - 1); ch = Urdu.ToUrdu(ch); s = s + String.valueOf(ch); tf.setString(""); tf.setString(s); }//end if throw new UnsupportedOperationException("Not supported yet."); } } }

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Remove accents from String .NET

- by developerit

Private Const ACCENT As String = “ÀÁÂÃÄÅàáâãäåÒÓÔÕÖØòóôõöøÈÉÊËèéêëÌÍÎÏìíîïÙÚÛÜùúûüÿÑñÇç” Private Const SANSACCENT As String = “AAAAAAaaaaaaOOOOOOooooooEEEEeeeeIIIIiiiiUUUUuuuuyNnCc” Public Shared Function FormatForUrl(ByVal uriBase As String) As String If String.IsNullOrEmpty(uriBase) Then Return uriBase End If ‘// Declaration de variables Dim chaine As String = uriBase.Trim.Replace(” “, “-”) chaine = chaine.Replace(” “c, “-”c) chaine = chaine.Replace(“–”, “-”) chaine = chaine.Replace(“‘”c, String.Empty) chaine = chaine.Replace(“?”c, String.Empty) chaine = chaine.Replace(“#”c, String.Empty) chaine = chaine.Replace(“:”c, String.Empty) chaine = chaine.Replace(“;”c, String.Empty) ‘// Conversion des chaines en tableaux de caractŠres Dim tableauSansAccent As Char() = SANSACCENT.ToCharArray Dim tableauAccent As Char() = ACCENT.ToCharArray ‘// Pour chaque accent For i As Integer = 0 To ACCENT.Length – 1 ‘ // Remplacement de l’accent par son ‚quivalent sans accent dans la chaŒne de caractŠres chaine = chaine.Replace(tableauAccent(i).ToString(), tableauSansAccent(i).ToString()) Next ‘// Retour du resultat Return chaine End Function

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Is there anyway to get the cyberphunks pidgin OTR plugin to be less verbose?

- by Matt

Is there anyway to get the cyberphunk piding OTR plugin to be less verbose? Sometimes I get hundreds of lines notifying me of the same thing... (6:40:56 PM) OTR Error: You sent encrypted data to anoynmous, who wasn't expecting it. (6:40:57 PM) Successfully refreshed the unverified conversation with [email protected]/Gaim939DD745. (6:40:57 PM) The last message to [email protected] was resent. (6:40:57 PM) Error setting up private conversation: Malformed message received (6:40:58 PM) OTR Error: You sent encrypted data to anoynmous, who wasn't expecting it. (6:40:58 PM) Successfully refreshed the unverified conversation with [email protected]/Gaim939DD745. (6:40:58 PM) The last message to [email protected] was resent. (6:40:59 PM) Error setting up private conversation: Malformed message received (6:40:59 PM) OTR Error: You sent encrypted data to anoynmous, who wasn't expecting it. (6:41:00 PM) Successfully refreshed the unverified conversation with [email protected]/Gaim939DD745. (6:41:00 PM) The last message to [email protected] was resent. (6:41:00 PM) Error setting up private conversation: Malformed message received (6:41:01 PM) OTR Error: You sent encrypted data to anoynmous, who wasn't expecting it. (6:41:01 PM) Attempting to refresh the private conversation with [email protected]/Gaim939DD745... (6:41:01 PM) Successfully refreshed the unverified conversation with [email protected]/Gaim939DD745. (6:41:01 PM) The last message to [email protected] was resent. (6:41:02 PM) OTR Error: You transmitted an unreadable encrypted message. (6:41:02 PM) Error setting up private conversation: Malformed message received (6:41:02 PM) OTR Error: You sent encrypted data to anoynmous, who wasn't expecting it. (6:41:02 PM) Successfully refreshed the unverified conversation with [email protected]/Gaim939DD745. (6:41:02 PM) The last message to [email protected] was resent. (6:41:03 PM) Error setting up private conversation: Malformed message received (6:41:03 PM) OTR Error: You transmitted an unreadable encrypted message. (6:41:03 PM) Successfully refreshed the unverified conversation with [email protected]/Gaim939DD745. (6:41:03 PM) The last message to [email protected] was resent. (6:41:03 PM) OTR Error: You sent encrypted data to anoynmous, who wasn't expecting it. (6:41:04 PM) Error setting up private conversation: Malformed message received (6:41:09 PM) Attempting to refresh the private conversation with [email protected]/Adium39B22966... (6:41:11 PM) Unverified conversation with [email protected]/Adium39B22966 started. (6:41:11 PM) The last message to [email protected] was resent. (6:41:11 PM) OTR Error: You transmitted an unreadable encrypted message. **(6:41:16 PM) Anonymous: yea** (6:41:20 PM) [email protected]/91A31EC5: yarrr (**6:41:25 PM) Anonymous: sup? (6:41:29 PM) [email protected]/91A31EC5: nothing (6:41:33 PM) [email protected]/91A31EC5: just speaking like a pirate (6:41:51 PM) Anonymous: word (7:13:47 PM) Anonymous: how late you workin? (9:18:12 PM) [email protected]/91A31EC5: not too late** (9:18:13 PM) OTR Error: You transmitted an unreadable encrypted message. (9:18:13 PM) Unverified conversation with [email protected]/Gaim939DD745 started. (9:18:13 PM) The last message to [email protected] was resent. (9:18:14 PM) Error setting up private conversation: Malformed message received (9:18:14 PM) OTR Error: You transmitted an unreadable encrypted message. (9:18:14 PM) Unverified conversation with [email protected]/Adium39B22966 started. (9:18:14 PM) The last message to [email protected] was resent. (9:18:15 PM) OTR Error: You transmitted an unreadable encrypted message. (9:18:15 PM) Unverified conversation with [email protected]/Gaim939DD745 started. (9:18:15 PM) The last message to [email protected] was resent. (9:18:15 PM) OTR Error: You transmitted an unreadable encrypted message. (9:18:16 PM) Successfully refreshed the unverified conversation with [email protected]/Gaim939DD745. (9:18:16 PM) The last message to [email protected] was resent. (9:18:16 PM) OTR Error: You transmitted an unreadable encrypted message. (9:18:17 PM) Successfully refreshed the unverified conversation with [email protected]/Gaim939DD745. (9:18:17 PM) The last message to [email protected] was resent. (9:18:17 PM) OTR Error: You transmitted an unreadable encrypted message. (9:18:18 PM) Successfully refreshed the unverified conversation with [email protected]/Gaim939DD745. (9:18:18 PM) The last message to [email protected] was resent. (9:18:18 PM) OTR Error: You transmitted an unreadable encrypted message. (9:18:19 PM) Unverified conversation with [email protected]/Adium39B22966 started. (9:18:19 PM) The last message to [email protected] was resent. (9:18:19 PM) OTR Error: You transmitted an unreadable encrypted message. (9:18:20 PM) Successfully refreshed the unverified conversation with [email protected]/Adium39B22966. (9:18:20 PM) The last message to [email protected] was resent. (9:18:20 PM) OTR Error: You transmitted an unreadable encrypted message. (9:18:20 PM) Attempting to refresh the private conversation with [email protected]/Gaim939DD745... (9:18:21 PM) Unverified conversation with [email protected]/Gaim939DD745 started. (9:18:21 PM) The last message to [email protected] was resent. (9:18:21 PM) OTR Error: You transmitted an unreadable encrypted message. (9:18:21 PM) OTR Error: You transmitted an unreadable encrypted message. (9:18:21 PM) Successfully refreshed the unverified conversation with [email protected]/Gaim939DD745. (9:18:21 PM) The last message to [email protected] was resent. (9:18:21 PM) OTR Error: You transmitted an unreadable encrypted message. (9:18:22 PM) We received an unreadable encrypted message from [email protected]. (9:18:23 PM) The last message to [email protected] was resent. (9:18:24 PM) OTR Error: You transmitted an unreadable encrypted message. (9:18:25 PM) We received an unreadable encrypted message from [email protected]. (9:18:26 PM) Unverified conversation with [email protected]/Adium39B22966 started. (9:18:26 PM) The last message to [email protected] was resent.

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Random movement of wandering monsters in x & y axis in LibGDX

- by Vishal Kumar

I am making a simple top down RPG game in LibGDX. What I want is ... the enemies should wander here and there in x and y directions in certain interval so that it looks natural that they are guarding something. I spend several hours doing this but could not achieve what I want. After a long time of coding, I came with this code. But what I observed is when enemies come to an end of x or start of x or start of y or end of y of the map. It starts flickering for random intervals. Sometimes they remain nice, sometimes, they start flickering for long time. public class Enemy extends Sprite { public float MAX_VELOCITY = 0.05f; public static final int MOVING_LEFT = 0; public static final int MOVING_RIGHT = 1; public static final int MOVING_UP = 2; public static final int MOVING_DOWN = 3; public static final int HORIZONTAL_GUARD = 0; public static final int VERTICAL_GUARD = 1; public static final int RANDOM_GUARD = 2; private float startTime = System.nanoTime(); private static float SECONDS_TIME = 0; private boolean randomDecider; public int enemyType; public static final float width = 30 * World.WORLD_UNIT; public static final float height = 32 * World.WORLD_UNIT; public int state; public float stateTime; public boolean visible; public boolean dead; public Enemy(float x, float y, int enemyType) { super(x, y); state = MOVING_LEFT; this.enemyType = enemyType; stateTime = 0; visible = true; dead = false; boolean random = Math.random()>=0.5f ? true :false; if(enemyType == HORIZONTAL_GUARD){ if(random) velocity.x = -MAX_VELOCITY; else velocity.x = MAX_VELOCITY; } if(enemyType == VERTICAL_GUARD){ if(random) velocity.y = -MAX_VELOCITY; else velocity.y = MAX_VELOCITY; } if(enemyType == RANDOM_GUARD){ //if(random) //velocity.x = -MAX_VELOCITY; //else //velocity.y = MAX_VELOCITY; } } public void update(Enemy e, float deltaTime) { super.update(deltaTime); e.stateTime+= deltaTime; e.position.add(velocity); // This is for updating the Animation for Enemy Movement Direction. VERY IMPORTANT FOR REAL EFFECTS updateDirections(); //Here the various movement methods are called depending upon the type of the Enemy if(e.enemyType == HORIZONTAL_GUARD) guardHorizontally(); if(e.enemyType == VERTICAL_GUARD) guardVertically(); if(e.enemyType == RANDOM_GUARD) guardRandomly(); //quadrantMovement(e, deltaTime); } private void guardHorizontally(){ if(position.x <= 0){ velocity.x= MAX_VELOCITY; velocity.y= 0; } else if(position.x>= World.mapWidth-width){ velocity.x= -MAX_VELOCITY; velocity.y= 0; } } private void guardVertically(){ if(position.y<= 0){ velocity.y= MAX_VELOCITY; velocity.x= 0; } else if(position.y>= World.mapHeight- height){ velocity.y= -MAX_VELOCITY; velocity.x= 0; } } private void guardRandomly(){ if (System.nanoTime() - startTime >= 1000000000) { SECONDS_TIME++; if(SECONDS_TIME % 5==0) randomDecider = Math.random()>=0.5f ? true :false; if(SECONDS_TIME>=30) SECONDS_TIME =0; startTime = System.nanoTime(); } if(SECONDS_TIME <=30){ if(randomDecider && position.x >= 0) velocity.x= -MAX_VELOCITY; else{ if(position.x < World.mapWidth-width) velocity.x= MAX_VELOCITY; else velocity.x= -MAX_VELOCITY; } velocity.y =0; } else{ if(randomDecider && position.y >0) velocity.y= -MAX_VELOCITY; else velocity.y= MAX_VELOCITY; velocity.x =0; } /* //This is essential so as to keep the enemies inside the boundary of the Map if(position.x <= 0){ velocity.x= MAX_VELOCITY; //velocity.y= 0; } else if(position.x>= World.mapWidth-width){ velocity.x= -MAX_VELOCITY; //velocity.y= 0; } else if(position.y<= 0){ velocity.y= MAX_VELOCITY; //velocity.x= 0; } else if(position.y>= World.mapHeight- height){ velocity.y= -MAX_VELOCITY; //velocity.x= 0; } */ } private void updateDirections() { if(velocity.x > 0) state = MOVING_RIGHT; else if(velocity.x<0) state = MOVING_LEFT; else if(velocity.y>0) state = MOVING_UP; else if(velocity.y<0) state = MOVING_DOWN; } public Rectangle getBounds() { return new Rectangle(position.x, position.y, width, height); } private void quadrantMovement(Enemy e, float deltaTime) { int temp = e.getEnemyQuadrant(e.position.x, e.position.y); boolean random = Math.random()>=0.5f ? true :false; switch(temp){ case 1: velocity.x = MAX_VELOCITY; break; case 2: velocity.x = MAX_VELOCITY; break; case 3: velocity.x = -MAX_VELOCITY; break; case 4: velocity.x = -MAX_VELOCITY; break; default: if(random) velocity.x = MAX_VELOCITY; else velocity.y =-MAX_VELOCITY; } } public float getDistanceFromPoint(float p1,float p2){ Vector2 v1 = new Vector2(p1,p2); return position.dst(v1); } private int getEnemyQuadrant(float x, float y){ Rectangle enemyQuad = new Rectangle(x, y, 30, 32); if(ScreenQuadrants.getQuad1().contains(enemyQuad)) return 1; if(ScreenQuadrants.getQuad2().contains(enemyQuad)) return 2; if(ScreenQuadrants.getQuad3().contains(enemyQuad)) return 3; if(ScreenQuadrants.getQuad4().contains(enemyQuad)) return 4; return 0; } } Is there a better way of doing this. I am new to game development. I shall be very grateful to any help or reference.

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2 Templates to one SharePoint Library, Default templates

- by Anarkie

Ok, I'm not a script writer, otherwise I'd have this automated already. I need a quick assist in the most basic steps possible. I have a SharePoint form library using InfoPath based forms. I have a "Public" template for my customers which submits to a "Private" library, through very granulated permissions so they cannot view the library. The Private library has it's own template based on the original Public template. This way I can transition one form's information seamlessly to the new template. The new Private template would have all of the internal details that we do not want the customer to see, but also all information fron the customer-filled Public form. Is there any way to default all items opened from the Private library to use the Private Template, even though they were submitted form the Public template?

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Curious about IObservable? Here’s a quick example to get you started!

- by Roman Schindlauer

Have you heard about IObservable/IObserver support in Microsoft StreamInsight 1.1? Then you probably want to try it out. If this is your first incursion into the IObservable/IObserver pattern, this blog post is for you! StreamInsight 1.1 introduced the ability to use IEnumerable and IObservable objects as event sources and sinks. The IEnumerable case is pretty straightforward, since many data collections are already surfacing as this type. This was already covered by Colin in his blog. Creating your own IObservable event source is a little more involved but no less exciting – here is a primer: First, let’s look at a very simple Observable data source. All it does is publish an integer in regular time periods to its registered observers. (For more information on IObservable, see http://msdn.microsoft.com/en-us/library/dd990377.aspx ). sealed class RandomSubject : IObservable<int>, IDisposable { private bool _done; private readonly List<IObserver<int>> _observers; private readonly Random _random; private readonly object _sync; private readonly Timer _timer; private readonly int _timerPeriod; /// <summary> /// Random observable subject. It produces an integer in regular time periods. /// </summary> /// <param name="timerPeriod">Timer period (in milliseconds)</param> public RandomSubject(int timerPeriod) { _done = false; _observers = new List<IObserver<int>>(); _random = new Random(); _sync = new object(); _timer = new Timer(EmitRandomValue); _timerPeriod = timerPeriod; Schedule(); } public IDisposable Subscribe(IObserver<int> observer) { lock (_sync) { _observers.Add(observer); } return new Subscription(this, observer); } public void OnNext(int value) { lock (_sync) { if (!_done) { foreach (var observer in _observers) { observer.OnNext(value); } } } } public void OnError(Exception e) { lock (_sync) { foreach (var observer in _observers) { observer.OnError(e); } _done = true; } } public void OnCompleted() { lock (_sync) { foreach (var observer in _observers) { observer.OnCompleted(); } _done = true; } } void IDisposable.Dispose() { _timer.Dispose(); } private void Schedule() { lock (_sync) { if (!_done) { _timer.Change(_timerPeriod, Timeout.Infinite); } } } private void EmitRandomValue(object _) { var value = (int)(_random.NextDouble() * 100); Console.WriteLine("[Observable]\t" + value); OnNext(value); Schedule(); } private sealed class Subscription : IDisposable { private readonly RandomSubject _subject; private IObserver<int> _observer; public Subscription(RandomSubject subject, IObserver<int> observer) { _subject = subject; _observer = observer; } public void Dispose() { IObserver<int> observer = _observer; if (null != observer) { lock (_subject._sync) { _subject._observers.Remove(observer); } _observer = null; } } } } So far, so good. Now let’s write a program that consumes data emitted by the observable as a stream of point events in a Streaminsight query. First, let’s define our payload type: class Payload { public int Value { get; set; } public override string ToString() { return "[StreamInsight]\tValue: " + Value.ToString(); } } Now, let’s write the program. First, we will instantiate the observable subject. Then we’ll use the ToPointStream() method to consume it as a stream. We can now write any query over the source - here, a simple pass-through query. class Program { static void Main(string[] args) { Console.WriteLine("Starting observable source..."); using (var source = new RandomSubject(500)) { Console.WriteLine("Started observable source."); using (var server = Server.Create("Default")) { var application = server.CreateApplication("My Application"); var stream = source.ToPointStream(application, e => PointEvent.CreateInsert(DateTime.Now, new Payload { Value = e }), AdvanceTimeSettings.StrictlyIncreasingStartTime, "Observable Stream"); var query = from e in stream select e; [...] We’re done with consuming input and querying it! But you probably want to see the output of the query. Did you know you can turn a query into an observable subject as well? Let’s do precisely that, and exploit the Reactive Extensions for .NET (http://msdn.microsoft.com/en-us/devlabs/ee794896.aspx) to quickly visualize the output. Notice we’re subscribing “Console.WriteLine()” to the query, a pattern you may find useful for quick debugging of your queries. Reminder: you’ll need to install the Reactive Extensions for .NET (Rx for .NET Framework 4.0), and reference System.CoreEx and System.Reactive in your project. [...] Console.ReadLine(); Console.WriteLine("Starting query..."); using (query.ToObservable().Subscribe(Console.WriteLine)) { Console.WriteLine("Started query."); Console.ReadLine(); Console.WriteLine("Stopping query..."); } Console.WriteLine("Stopped query."); } Console.ReadLine(); Console.WriteLine("Stopping observable source..."); source.OnCompleted(); } Console.WriteLine("Stopped observable source."); } } We hope this blog post gets you started. And for bonus points, you can go ahead and rewrite the observable source (the RandomSubject class) using the Reactive Extensions for .NET! The entire sample project is attached to this article. Happy querying! Regards, The StreamInsight Team

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Static objects and concurrency in a web application

- by Ionut

I'm developing small Java Web Applications on Tomcat server and I'm using MySQL as my database. Up until now I was using a connection singleton for accessing the database but I found out that this will ensure just on connection per Application and there will be problems if multiple users want to access the database in the same time. (They all have to make us of that single Connection object). I created a Connection Pool and I hope that this is the correct way of doing things. Furthermore it seems that I developed the bad habit of creating a lot of static object and static methods (mainly because I was under the wrong impression that every static object will be duplicated for every client which accesses my application). Because of this all the Service Classes ( classes used to handle database data) are static and distributed through a ServiceFactory: public class ServiceFactory { private static final String JDBC = "JDBC"; private static String impl; private static AccountService accountService; private static BoardService boardService; public static AccountService getAccountService(){ initConfig(); if (accountService == null){ if (impl.equalsIgnoreCase(JDBC)){ accountService = new JDBCAccountService(); } } return accountService; } public static BoardService getBoardService(){ initConfig(); if (boardService == null){ if (impl.equalsIgnoreCase(JDBC)){ boardService = new JDBCBoardService(); } } return boardService; } private static void initConfig(){ if (StringUtil.isEmpty(impl)){ impl = ConfigUtil.getProperty("service.implementation"); // If the config failed initialize with standard if (StringUtil.isEmpty(impl)){ impl = JDBC; } } } This was the factory class which, as you can see, allows just one Service to exist at any time. Now, is this a bad practice? What happens if let's say 1k users access AccountService simultaneously? I know that all this questions and bad practices come from a bad understanding of the static attribute in a web application and the way the server handles this attributes. Any help on this topic would be more than welcomed. Thank you for your time!

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Reverse subarray of an array with O(1)

- by Babibu

I have an idea how to implement sub array reverse with O(1), not including precalculation such as reading the input. I will have many reverse operations, and I can't use the trivial solution of O(N). Edit: To be more clear I want to build data structure behind the array with access layer that knows about reversing requests and inverts the indexing logic as necessary when someone wants to iterate over the array. Edit 2: The data structure will only be used for iterations I been reading this and this and even this questions but they aren't helping. There are 3 cases that need to be taking care of: Regular reverse operation Reverse that including reversed area Intersection between reverse and part of other reversed area in the array Here is my implementation for the first two parts, I will need your help with the last one. This is the rule class: class Rule { public int startingIndex; public int weight; } It is used in my basic data structure City: public class City { Rule rule; private static AtomicInteger _counter = new AtomicInteger(-1); public final int id = _counter.incrementAndGet(); @Override public String toString() { return "" + id; } } This is the main class: public class CitiesList implements Iterable<City>, Iterator<City> { private int position; private int direction = 1; private ArrayList<City> cities; private ArrayDeque<City> citiesQeque = new ArrayDeque<>(); private LinkedList<Rule> rulesQeque = new LinkedList<>(); public void init(ArrayList<City> cities) { this.cities = cities; } public void swap(int index1, int index2){ Rule rule = new Rule(); rule.weight = Math.abs(index2 - index1); cities.get(index1).rule = rule; cities.get(index2 + 1).rule = rule; } @Override public void remove() { throw new IllegalStateException("Not implemented"); } @Override public City next() { City city = cities.get(position); if (citiesQeque.peek() == city){ citiesQeque.pop(); changeDirection(); position += (city.rule.weight + 1) * direction; city = cities.get(position); } if(city.rule != null){ if(city.rule != rulesQeque.peekLast()){ rulesQeque.add(city.rule); position += city.rule.weight * direction; changeDirection(); citiesQeque.push(city); } else{ rulesQeque.removeLast(); position += direction; } } else{ position += direction; } return city; } private void changeDirection() { direction *= -1; } @Override public boolean hasNext() { return position < cities.size(); } @Override public Iterator<City> iterator() { position = 0; return this; } } And here is a sample program: public static void main(String[] args) { ArrayList<City> list = new ArrayList<>(); for(int i = 0 ; i < 20; i++){ list.add(new City()); } CitiesList citiesList = new CitiesList(); citiesList.init(list); for (City city : citiesList) { System.out.print(city + " "); } System.out.println("\n******************"); citiesList.swap(4, 8); for (City city : citiesList) { System.out.print(city + " "); } System.out.println("\n******************"); citiesList.swap(2, 15); for (City city : citiesList) { System.out.print(city + " "); } } How do I handle reverse intersections?

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Unification of TPL TaskScheduler and RX IScheduler

- by JoshReuben

using System; using System.Collections.Generic; using System.Reactive.Concurrency; using System.Security; using System.Threading; using System.Threading.Tasks; using System.Windows.Threading; namespace TPLRXSchedulerIntegration { public class MyScheduler :TaskScheduler, IScheduler { private readonly Dispatcher _dispatcher; private readonly DispatcherScheduler _rxDispatcherScheduler; //private readonly TaskScheduler _tplDispatcherScheduler; private readonly SynchronizationContext _synchronizationContext; public MyScheduler(Dispatcher dispatcher) { _dispatcher = dispatcher; _rxDispatcherScheduler = new DispatcherScheduler(dispatcher); //_tplDispatcherScheduler = FromCurrentSynchronizationContext(); _synchronizationContext = SynchronizationContext.Current; } #region RX public DateTimeOffset Now { get { return _rxDispatcherScheduler.Now; } } public IDisposable Schedule<TState>(TState state, DateTimeOffset dueTime, Func<IScheduler, TState, IDisposable> action) { return _rxDispatcherScheduler.Schedule(state, dueTime, action); } public IDisposable Schedule<TState>(TState state, TimeSpan dueTime, Func<IScheduler, TState, IDisposable> action) { return _rxDispatcherScheduler.Schedule(state, dueTime, action); } public IDisposable Schedule<TState>(TState state, Func<IScheduler, TState, IDisposable> action) { return _rxDispatcherScheduler.Schedule(state, action); } #endregion #region TPL /// Simply posts the tasks to be executed on the associated SynchronizationContext [SecurityCritical] protected override void QueueTask(Task task) { _dispatcher.BeginInvoke((Action)(() => TryExecuteTask(task))); //TryExecuteTaskInline(task,false); //task.Start(_tplDispatcherScheduler); //m_synchronizationContext.Post(s_postCallback, (object)task); } /// The task will be executed inline only if the call happens within the associated SynchronizationContext [SecurityCritical] protected override bool TryExecuteTaskInline(Task task, bool taskWasPreviouslyQueued) { if (SynchronizationContext.Current != _synchronizationContext) { SynchronizationContext.SetSynchronizationContext(_synchronizationContext); } return TryExecuteTask(task); } // not implemented [SecurityCritical] protected override IEnumerable<Task> GetScheduledTasks() { return null; } /// Implementes the MaximumConcurrencyLevel property for this scheduler class. /// By default it returns 1, because a <see cref="T:System.Threading.SynchronizationContext"/> based /// scheduler only supports execution on a single thread. public override Int32 MaximumConcurrencyLevel { get { return 1; } } //// preallocated SendOrPostCallback delegate //private static SendOrPostCallback s_postCallback = new SendOrPostCallback(PostCallback); //// this is where the actual task invocation occures //private static void PostCallback(object obj) //{ // Task task = (Task) obj; // // calling ExecuteEntry with double execute check enabled because a user implemented SynchronizationContext could be buggy // task.ExecuteEntry(true); //} #endregion } } What Design Pattern did I use here?

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InvalidProgramException Running Unit Test (Bug Closed)

- by Anthony Trudeau

In a previous post I reported an InvalidProgramException that occurs in a certain circumstance with unit tests involving accessors on a private generic method. It turns out that Bug #635093 reported through Microsoft Connect will not be fixed. The reason cited is that private accessors have been discontinued. And why have private accessors been discontinued? They don't have time is the reason listed in the blog post titled "Generation of Private Accessors (Publicize) and Code Generation for Visual Studio 2010". In my opinion, it's a piss poor decision to discontinue support for a feature that they're still using within automatically generated unit tests against private classes and methods. But, I think what is worse is the lack of guidance cited in the aforementioned blog post. Their advice? Use the PrivateObject to help, but develop your own framework. At the end of the day what Microsoft is saying is, "I know you spent a lot of money for this product. I know that you don't have time to develop a framework to deal with this. We don't have time and that is all that's important."

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LogMeIn Hamachi

Easily create and manage your own virtual private network (VPN) for secure communication between PCs

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Developing custom MBeans to manage J2EE Applications (Part III)

- by philippe Le Mouel

This is the third and final part in a series of blogs, that demonstrate how to add management capability to your own application using JMX MBeans. In Part I we saw: How to implement a custom MBean to manage configuration associated with an application. How to package the resulting code and configuration as part of the application's ear file. How to register MBeans upon application startup, and unregistered them upon application stop (or undeployment). How to use generic JMX clients such as JConsole to browse and edit our application's MBean. In Part II we saw: How to add localized descriptions to our MBean, MBean attributes, MBean operations and MBean operation parameters. How to specify meaningful name to our MBean operation parameters. We also touched on future enhancements that will simplify how we can implement localized MBeans. In this third and last part, we will re-write our MBean to simplify how we added localized descriptions. To do so we will take advantage of the functionality we already described in part II and that is now part of WebLogic 10.3.3.0. We will show how to take advantage of WebLogic's localization support to localize our MBeans based on the client's Locale independently of the server's Locale. Each client will see MBean descriptions localized based on his/her own Locale. We will show how to achieve this using JConsole, and also using a sample programmatic JMX Java client. The complete code sample and associated build files for part III are available as a zip file. The code has been tested against WebLogic Server 10.3.3.0 and JDK6. To build and deploy our sample application, please follow the instruction provided in Part I, as they also apply to part III's code and associated zip file. Providing custom descriptions take II In part II we localized our MBean descriptions by extending the StandardMBean class and overriding its many getDescription methods. WebLogic 10.3.3.0 similarly to JDK 7 can automatically localize MBean descriptions as long as those are specified according to the following conventions: Descriptions resource bundle keys are named according to: MBean description: <MBeanInterfaceClass>.mbean MBean attribute description: <MBeanInterfaceClass>.attribute.<AttributeName> MBean operation description: <MBeanInterfaceClass>.operation.<OperationName> MBean operation parameter description: <MBeanInterfaceClass>.operation.<OperationName>.<ParameterName> MBean constructor description: <MBeanInterfaceClass>.constructor.<ConstructorName> MBean constructor parameter description: <MBeanInterfaceClass>.constructor.<ConstructorName>.<ParameterName> We also purposely named our resource bundle class MBeanDescriptions and included it as part of the same package as our MBean. We already followed the above conventions when creating our resource bundle in part II, and our default resource bundle class with English descriptions looks like: package blog.wls.jmx.appmbean; import java.util.ListResourceBundle; public class MBeanDescriptions extends ListResourceBundle { protected Object[][] getContents() { return new Object[][] { {"PropertyConfigMXBean.mbean", "MBean used to manage persistent application properties"}, {"PropertyConfigMXBean.attribute.Properties", "Properties associated with the running application"}, {"PropertyConfigMXBean.operation.setProperty", "Create a new property, or change the value of an existing property"}, {"PropertyConfigMXBean.operation.setProperty.key", "Name that identify the property to set."}, {"PropertyConfigMXBean.operation.setProperty.value", "Value for the property being set"}, {"PropertyConfigMXBean.operation.getProperty", "Get the value for an existing property"}, {"PropertyConfigMXBean.operation.getProperty.key", "Name that identify the property to be retrieved"} }; } } We have now also added a resource bundle with French localized descriptions: package blog.wls.jmx.appmbean; import java.util.ListResourceBundle; public class MBeanDescriptions_fr extends ListResourceBundle { protected Object[][] getContents() { return new Object[][] { {"PropertyConfigMXBean.mbean", "Manage proprietes sauvegarde dans un fichier disque."}, {"PropertyConfigMXBean.attribute.Properties", "Proprietes associee avec l'application en cour d'execution"}, {"PropertyConfigMXBean.operation.setProperty", "Construit une nouvelle proprietee, ou change la valeur d'une proprietee existante."}, {"PropertyConfigMXBean.operation.setProperty.key", "Nom de la propriete dont la valeur est change."}, {"PropertyConfigMXBean.operation.setProperty.value", "Nouvelle valeur"}, {"PropertyConfigMXBean.operation.getProperty", "Retourne la valeur d'une propriete existante."}, {"PropertyConfigMXBean.operation.getProperty.key", "Nom de la propriete a retrouver."} }; } } So now we can just remove the many getDescriptions methods from our MBean code, and have a much cleaner: package blog.wls.jmx.appmbean; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.File; import java.net.URL; import java.util.Map; import java.util.HashMap; import java.util.Properties; import javax.management.MBeanServer; import javax.management.ObjectName; import javax.management.MBeanRegistration; import javax.management.StandardMBean; import javax.management.MBeanOperationInfo; import javax.management.MBeanParameterInfo; public class PropertyConfig extends StandardMBean implements PropertyConfigMXBean, MBeanRegistration { private String relativePath_ = null; private Properties props_ = null; private File resource_ = null; private static Map operationsParamNames_ = null; static { operationsParamNames_ = new HashMap(); operationsParamNames_.put("setProperty", new String[] {"key", "value"}); operationsParamNames_.put("getProperty", new String[] {"key"}); } public PropertyConfig(String relativePath) throws Exception { super(PropertyConfigMXBean.class , true); props_ = new Properties(); relativePath_ = relativePath; } public String setProperty(String key, String value) throws IOException { String oldValue = null; if (value == null) { oldValue = String.class.cast(props_.remove(key)); } else { oldValue = String.class.cast(props_.setProperty(key, value)); } save(); return oldValue; } public String getProperty(String key) { return props_.getProperty(key); } public Map getProperties() { return (Map) props_; } private void load() throws IOException { InputStream is = new FileInputStream(resource_); try { props_.load(is); } finally { is.close(); } } private void save() throws IOException { OutputStream os = new FileOutputStream(resource_); try { props_.store(os, null); } finally { os.close(); } } public ObjectName preRegister(MBeanServer server, ObjectName name) throws Exception { // MBean must be registered from an application thread // to have access to the application ClassLoader ClassLoader cl = Thread.currentThread().getContextClassLoader(); URL resourceUrl = cl.getResource(relativePath_); resource_ = new File(resourceUrl.toURI()); load(); return name; } public void postRegister(Boolean registrationDone) { } public void preDeregister() throws Exception {} public void postDeregister() {} protected String getParameterName(MBeanOperationInfo op, MBeanParameterInfo param, int sequence) { return operationsParamNames_.get(op.getName())[sequence]; } } The only reason we are still extending the StandardMBean class, is to override the default values for our operations parameters name. If this isn't a concern, then one could just write the following code: package blog.wls.jmx.appmbean; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.File; import java.net.URL; import java.util.Properties; import javax.management.MBeanServer; import javax.management.ObjectName; import javax.management.MBeanRegistration; import javax.management.StandardMBean; import javax.management.MBeanOperationInfo; import javax.management.MBeanParameterInfo; public class PropertyConfig implements PropertyConfigMXBean, MBeanRegistration { private String relativePath_ = null; private Properties props_ = null; private File resource_ = null; public PropertyConfig(String relativePath) throws Exception { props_ = new Properties(); relativePath_ = relativePath; } public String setProperty(String key, String value) throws IOException { String oldValue = null; if (value == null) { oldValue = String.class.cast(props_.remove(key)); } else { oldValue = String.class.cast(props_.setProperty(key, value)); } save(); return oldValue; } public String getProperty(String key) { return props_.getProperty(key); } public Map getProperties() { return (Map) props_; } private void load() throws IOException { InputStream is = new FileInputStream(resource_); try { props_.load(is); } finally { is.close(); } } private void save() throws IOException { OutputStream os = new FileOutputStream(resource_); try { props_.store(os, null); } finally { os.close(); } } public ObjectName preRegister(MBeanServer server, ObjectName name) throws Exception { // MBean must be registered from an application thread // to have access to the application ClassLoader ClassLoader cl = Thread.currentThread().getContextClassLoader(); URL resourceUrl = cl.getResource(relativePath_); resource_ = new File(resourceUrl.toURI()); load(); return name; } public void postRegister(Boolean registrationDone) { } public void preDeregister() throws Exception {} public void postDeregister() {} } Note: The above would also require changing the operations parameters name in the resource bundle classes. For instance: PropertyConfigMXBean.operation.setProperty.key would become: PropertyConfigMXBean.operation.setProperty.p0 Client based localization When accessing our MBean using JConsole started with the following command line: jconsole -J-Djava.class.path=$JAVA_HOME/lib/jconsole.jar:$JAVA_HOME/lib/tools.jar: $WL_HOME/server/lib/wljmxclient.jar -J-Djmx.remote.protocol.provider.pkgs=weblogic.management.remote -debug We see that our MBean descriptions are localized according to the WebLogic's server Locale. English in this case: Note: Consult Part I for information on how to use JConsole to browse/edit our MBean. Now if we specify the client's Locale as part of the JConsole command line as follow: jconsole -J-Djava.class.path=$JAVA_HOME/lib/jconsole.jar:$JAVA_HOME/lib/tools.jar: $WL_HOME/server/lib/wljmxclient.jar -J-Djmx.remote.protocol.provider.pkgs=weblogic.management.remote -J-Dweblogic.management.remote.locale=fr-FR -debug We see that our MBean descriptions are now localized according to the specified client's Locale. French in this case: We use the weblogic.management.remote.locale system property to specify the Locale that should be associated with the cient's JMX connections. The value is composed of the client's language code and its country code separated by the - character. The country code is not required, and can be omitted. For instance: -Dweblogic.management.remote.locale=fr We can also specify the client's Locale using a programmatic client as demonstrated below: package blog.wls.jmx.appmbean.client; import javax.management.MBeanServerConnection; import javax.management.ObjectName; import javax.management.MBeanInfo; import javax.management.remote.JMXConnector; import javax.management.remote.JMXServiceURL; import javax.management.remote.JMXConnectorFactory; import java.util.Hashtable; import java.util.Set; import java.util.Locale; public class JMXClient { public static void main(String[] args) throws Exception { JMXConnector jmxCon = null; try { JMXServiceURL serviceUrl = new JMXServiceURL( "service:jmx:iiop://127.0.0.1:7001/jndi/weblogic.management.mbeanservers.runtime"); System.out.println("Connecting to: " + serviceUrl); // properties associated with the connection Hashtable env = new Hashtable(); env.put(JMXConnectorFactory.PROTOCOL_PROVIDER_PACKAGES, "weblogic.management.remote"); String[] credentials = new String[2]; credentials[0] = "weblogic"; credentials[1] = "weblogic"; env.put(JMXConnector.CREDENTIALS, credentials); // specifies the client's Locale env.put("weblogic.management.remote.locale", Locale.FRENCH); jmxCon = JMXConnectorFactory.newJMXConnector(serviceUrl, env); jmxCon.connect(); MBeanServerConnection con = jmxCon.getMBeanServerConnection(); Set mbeans = con.queryNames( new ObjectName( "blog.wls.jmx.appmbean:name=myAppProperties,type=PropertyConfig,*"), null); for (ObjectName mbeanName : mbeans) { System.out.println("\n\nMBEAN: " + mbeanName); MBeanInfo minfo = con.getMBeanInfo(mbeanName); System.out.println("MBean Description: "+minfo.getDescription()); System.out.println("\n"); } } finally { // release the connection if (jmxCon != null) jmxCon.close(); } } } The above client code is part of the zip file associated with this blog, and can be run using the provided client.sh script. The resulting output is shown below: $ ./client.sh Connecting to: service:jmx:iiop://127.0.0.1:7001/jndi/weblogic.management.mbeanservers.runtime MBEAN: blog.wls.jmx.appmbean:type=PropertyConfig,name=myAppProperties MBean Description: Manage proprietes sauvegarde dans un fichier disque. $ Miscellaneous Using Description annotation to specify MBean descriptions Earlier we have seen how to name our MBean descriptions resource keys, so that WebLogic 10.3.3.0 automatically uses them to localize our MBean. In some cases we might want to implicitly specify the resource key, and resource bundle. For instance when operations are overloaded, and the operation name is no longer sufficient to uniquely identify a single operation. In this case we can use the Description annotation provided by WebLogic as follow: import weblogic.management.utils.Description; @Description(resourceKey="myapp.resources.TestMXBean.description", resourceBundleBaseName="myapp.resources.MBeanResources") public interface TestMXBean { @Description(resourceKey="myapp.resources.TestMXBean.threshold.description", resourceBundleBaseName="myapp.resources.MBeanResources" ) public int getthreshold(); @Description(resourceKey="myapp.resources.TestMXBean.reset.description", resourceBundleBaseName="myapp.resources.MBeanResources") public int reset( @Description(resourceKey="myapp.resources.TestMXBean.reset.id.description", resourceBundleBaseName="myapp.resources.MBeanResources", displayNameKey= "myapp.resources.TestMXBean.reset.id.displayName.description") int id); } The Description annotation should be applied to the MBean interface. It can be used to specify MBean, MBean attributes, MBean operations, and MBean operation parameters descriptions as demonstrated above. Retrieving the Locale associated with a JMX operation from the MBean code There are several cases where it is necessary to retrieve the Locale associated with a JMX call from the MBean implementation. For instance this can be useful when localizing exception messages. This can be done as follow: import weblogic.management.mbeanservers.JMXContextUtil; ...... // some MBean method implementation public String setProperty(String key, String value) throws IOException { Locale callersLocale = JMXContextUtil.getLocale(); // use callersLocale to localize Exception messages or // potentially some return values such a Date .... } Conclusion With this last part we conclude our three part series on how to write MBeans to manage J2EE applications. We are far from having exhausted this particular topic, but we have gone a long way and are now capable to take advantage of the latest functionality provided by WebLogic's application server to write user friendly MBeans.

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Flixel Game Over Screen

- by Jamie Read

I am new to game development but familiar with programming languages. I have started using Flixel and have a working Breakout game with score and lives. I am just stuck on how I can create a new screen/game over screen if a player runs out of lives. I would like the process to be like following: Check IF lives are equal to 0 Pause the game and display a new screen (probably transparent) that says 'Game Over' When a user clicks or hits ENTER restart the level Here is the function I currently have to update the lives: private function loseLive(_ball:FlxObject, _bottomWall:FlxObject):void { // check for game over if (lives_count == 0) { } else { FlxG:lives_count -= 1; lives.text = 'Lives: ' + lives_count.toString() } } Here is my main game.as: package { import org.flixel.*; public class Game extends FlxGame { private const resolution:FlxPoint = new FlxPoint(640, 480); private const zoom:uint = 2; private const fps:uint = 60; public function Game() { super(resolution.x / zoom, resolution.y / zoom, PlayState, zoom); FlxG.flashFramerate = fps; } } }

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TFS 2010 SDK: Integrating Twitter with TFS Programmatically

- by Tarun Arora

Technorati Tags: Team Foundation Server 2010,TFS API,Integrate Twitter TFS,TFS Programming,ALM,TwitterSharp Friends at ‘Twitter Sharp’ have created a wonderful .net API for twitter. With this blog post i will try to show you a basic TFS – Twitter integration scenario where i will retrieve the Team Project details programmatically and then publish these details on my twitter page. In future blogs i will be demonstrating how to create a windows service to capture the events raised by TFS and then publishing them in your social eco-system. Download Working Demo: Integrate Twitter - Tfs Programmatically 1. Setting up Twitter API Download Tweet Sharp from => https://github.com/danielcrenna/tweetsharp Before you can start playing around with this, you will need to register an application on twitter. This is because Twitter uses the OAuth authentication protocol and will not issue an Access token unless your application is registered with them. Go to https://dev.twitter.com/ and register your application Once you have registered your application, you will need ‘Customer Key’, ‘Customer Secret’, ‘Access Token’, ‘Access Token Secret’ 2. Connecting to Twitter using the Tweet Sharp API Create a new C# windows forms project and add reference to ‘Hammock.ClientProfile’, ‘Newtonsoft.Json’, ‘TweetSharp’ Add the following keys to the App.config (Note – The values for the keys below are in correct and if you try and connect using them then you will get an authorization failure error). Add a new class ‘TwitterProxy’ and use the following code to connect to the TwitterService (Read more about OAuthentication - http://dev.twitter.com/pages/auth) using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Configuration;using TweetSharp; namespace WindowsFormsApplication2{ public class TwitterProxy { private static string _hero; private static string _consumerKey; private static string _consumerSecret; private static string _accessToken; private static string _accessTokenSecret; public static TwitterService ConnectToTwitter() { _consumerKey = ConfigurationManager.AppSettings["ConsumerKey"]; _consumerSecret = ConfigurationManager.AppSettings["ConsumerSecret"]; _accessToken = ConfigurationManager.AppSettings["AccessToken"]; _accessTokenSecret = ConfigurationManager.AppSettings["AccessTokenSecret"]; return new TwitterService(_consumerKey, _consumerSecret, _accessToken, _accessTokenSecret); } }} Time to Tweet! _twitterService = Proxy.TwitterProxy.ConnectToTwitter(); _twitterService.SendTweet("Hello World"); SendTweet will return the TweetStatus, If you do not get a 200 OK status that means you have failed authentication, please revisit the Access tokens. --RESPONSE: https://api.twitter.com/1/statuses/update.json HTTP/1.1 200 OK X-Transaction: 1308476106-69292-41752 X-Frame-Options: SAMEORIGIN X-Runtime: 0.03040 X-Transaction-Mask: a6183ffa5f44ef11425211f25 Pragma: no-cache X-Access-Level: read-write X-Revision: DEV X-MID: bd8aa0abeccb6efba38bc0a391a73fab98e983ea Cache-Control: no-cache, no-store, must-revalidate, pre-check=0, post-check=0 Content-Type: application/json; charset=utf-8 Date: Sun, 19 Jun 2011 09:35:06 GMT Expires: Tue, 31 Mar 1981 05:00:00 GMT Last-Modified: Sun, 19 Jun 2011 09:35:06 GMT Server: hi Vary: Accept-Encoding Content-Encoding: Keep-Alive: timeout=15, max=100 Connection: Keep-Alive Transfer-Encoding: chunked 3. Integrate with TFS In my blog post Connect to TFS Programmatically i have in depth demonstrated how to connect to TFS using the TFS API. 1: // Update the AppConfig with the URI of the Team Foundation Server you want to connect to, Make sure you have View Team Project Collection Details permissions on the server 2: private static string _myUri = ConfigurationManager.AppSettings["TfsUri"]; 3: private static TwitterService _twitterService = null; 4: 5: private void button1_Click(object sender, EventArgs e) 6: { 7: lblNotes.Text = string.Empty; 8: 9: try 10: { 11: StringBuilder notes = new StringBuilder(); 12: 13: _twitterService = Proxy.TwitterProxy.ConnectToTwitter(); 14: 15: _twitterService.SendTweet("Hello World"); 16: 17: TfsConfigurationServer configurationServer = 18: TfsConfigurationServerFactory.GetConfigurationServer(new Uri(_myUri)); 19: 20: CatalogNode catalogNode = configurationServer.CatalogNode; 21: 22: ReadOnlyCollection<CatalogNode> tpcNodes = catalogNode.QueryChildren( 23: new Guid[] { CatalogResourceTypes.ProjectCollection }, 24: false, CatalogQueryOptions.None); 25: 26: // tpc = Team Project Collection 27: foreach (CatalogNode tpcNode in tpcNodes) 28: { 29: Guid tpcId = new Guid(tpcNode.Resource.Properties["InstanceId"]); 30: TfsTeamProjectCollection tpc = configurationServer.GetTeamProjectCollection(tpcId); 31: 32: notes.AppendFormat("{0} Team Project Collection : {1}{0}", Environment.NewLine, tpc.Name); 33: _twitterService.SendTweet(String.Format("http://Lunartech.codeplex.com - Connecting to Team Project Collection : {0} ", tpc.Name)); 34: 35: // Get catalog of tp = 'Team Projects' for the tpc = 'Team Project Collection' 36: var tpNodes = tpcNode.QueryChildren( 37: new Guid[] { CatalogResourceTypes.TeamProject }, 38: false, CatalogQueryOptions.None); 39: 40: foreach (var p in tpNodes) 41: { 42: notes.AppendFormat("{0} Team Project : {1} - {2}{0}", Environment.NewLine, p.Resource.DisplayName, "This is an open source project hosted on codeplex"); 43: _twitterService.SendTweet(String.Format(" Connected to Team Project: '{0}' – '{1}' ", p.Resource.DisplayName, "This is an open source project hosted on codeplex")); 44: } 45: } 46: notes.AppendFormat("{0} Updates posted on Twitter : {1} {0}", Environment.NewLine, @"http://twitter.com/lunartech1"); 47: lblNotes.Text = notes.ToString(); 48: } 49: catch (Exception ex) 50: { 51: lblError.Text = " Message : " + ex.Message + (ex.InnerException != null ? " Inner Exception : " + ex.InnerException : string.Empty); 52: } 53: } The extensions you can build integrating TFS and Twitter are incredible! Share this post :

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UndoRedo on Nodes

- by Geertjan

When a change is made to the property in the Properties Window, below, the undo/redo functionality becomes enabled: When undo/redo are invoked, e.g., via the buttons in the toolbar, the display name of the node changes accordingly. The only problem I have is that the buttons only become enabled when the Person Window is selected, not when the Properties Window is selected, which would be desirable. Here's the Person object: public class Person implements PropertyChangeListener { private String name; public static final String PROP_NAME = "name"; public Person(String name) { this.name = name; } public String getName() { return name; } public void setName(String name) { String oldName = this.name; this.name = name; propertyChangeSupport.firePropertyChange(PROP_NAME, oldName, name); } private transient final PropertyChangeSupport propertyChangeSupport = new PropertyChangeSupport(this); public void addPropertyChangeListener(PropertyChangeListener listener) { propertyChangeSupport.addPropertyChangeListener(listener); } public void removePropertyChangeListener(PropertyChangeListener listener) { propertyChangeSupport.removePropertyChangeListener(listener); } @Override public void propertyChange(PropertyChangeEvent evt) { propertyChangeSupport.firePropertyChange(evt); } } And here's the Node with UndoRedo enablement: public class PersonNode extends AbstractNode implements UndoRedo.Provider, PropertyChangeListener { private UndoRedo.Manager manager = new UndoRedo.Manager(); private boolean undoRedoEvent; public PersonNode(Person person) { super(Children.LEAF, Lookups.singleton(person)); person.addPropertyChangeListener(this); setDisplayName(person.getName()); } @Override protected Sheet createSheet() { Sheet sheet = Sheet.createDefault(); Sheet.Set set = Sheet.createPropertiesSet(); set.put(new NameProperty(getLookup().lookup(Person.class))); sheet.put(set); return sheet; } @Override public void propertyChange(PropertyChangeEvent evt) { if (evt.getPropertyName().equals(Person.PROP_NAME)) { firePropertyChange(evt.getPropertyName(), evt.getOldValue(), evt.getNewValue()); } } public void fireUndoableEvent(String property, Person source, Object oldValue, Object newValue) { manager.addEdit(new MyAbstractUndoableEdit(source, oldValue, newValue)); } @Override public UndoRedo getUndoRedo() { return manager; } @Override public String getDisplayName() { Person p = getLookup().lookup(Person.class); if (p != null) { return p.getName(); } return super.getDisplayName(); } private class NameProperty extends PropertySupport.ReadWrite<String> { private Person p; public NameProperty(Person p) { super("name", String.class, "Name", "Name of Person"); this.p = p; } @Override public String getValue() throws IllegalAccessException, InvocationTargetException { return p.getName(); } @Override public void setValue(String newValue) throws IllegalAccessException, IllegalArgumentException, InvocationTargetException { String oldValue = p.getName(); p.setName(newValue); if (!undoRedoEvent) { fireUndoableEvent("name", p, oldValue, newValue); fireDisplayNameChange(oldValue, newValue); } } } class MyAbstractUndoableEdit extends AbstractUndoableEdit { private final String oldValue; private final String newValue; private final Person source; private MyAbstractUndoableEdit(Person source, Object oldValue, Object newValue) { this.oldValue = oldValue.toString(); this.newValue = newValue.toString(); this.source = source; } @Override public boolean canRedo() { return true; } @Override public boolean canUndo() { return true; } @Override public void undo() throws CannotUndoException { undoRedoEvent = true; source.setName(oldValue.toString()); fireDisplayNameChange(oldValue, newValue); undoRedoEvent = false; } @Override public void redo() throws CannotUndoException { undoRedoEvent = true; source.setName(newValue.toString()); fireDisplayNameChange(oldValue, newValue); undoRedoEvent = false; } } } Does anyone out there know how to have the Undo/Redo functionality enabled when the Properties Window is selected?

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Why Is Faulty Behaviour In The .NET Framework Not Fixed?

- by Alois Kraus

Here is the scenario: You have a Windows Form Application that calls a method via Invoke or BeginInvoke which throws exceptions. Now you want to find out where the error did occur and how the method has been called. Here is the output we do get when we call Begin/EndInvoke or simply Invoke The actual code that was executed was like this: private void cInvoke_Click(object sender, EventArgs e) { InvokingFunction(CallMode.Invoke); } [MethodImpl(MethodImplOptions.NoInlining)] void InvokingFunction(CallMode mode) { switch (mode) { case CallMode.Invoke: this.Invoke(new MethodInvoker(GenerateError)); The faulting method is called GenerateError which does throw a NotImplementedException exception and wraps it in a NotSupportedException. [MethodImpl(MethodImplOptions.NoInlining)] void GenerateError() { F1(); } private void F1() { try { F2(); } catch (Exception ex) { throw new NotSupportedException("Outer Exception", ex); } } private void F2() { throw new NotImplementedException("Inner Exception"); } It is clear that the method F2 and F1 did actually throw these exceptions but we do not see them in the call stack. If we directly call the InvokingFunction and catch and print the exception we can find out very easily how we did get into this situation. We see methods F1,F2,GenerateError and InvokingFunction directly in the stack trace and we see that actually two exceptions did occur. Here is for comparison what we get from Invoke/EndInvoke System.NotImplementedException: Inner Exception StackTrace: at System.Windows.Forms.Control.MarshaledInvoke(Control caller, Delegate method, Object[] args, Boolean synchronous) at System.Windows.Forms.Control.Invoke(Delegate method, Object[] args) at WindowsFormsApplication1.AppForm.InvokingFunction(CallMode mode) at WindowsFormsApplication1.AppForm.cInvoke_Click(Object sender, EventArgs e) at System.Windows.Forms.Control.OnClick(EventArgs e) at System.Windows.Forms.Button.OnClick(EventArgs e) The exception message is kept but the stack starts running from our Invoke call and not from the faulting method F2. We have therefore no clue where this exception did occur! The stack starts running at the method MarshaledInvoke because the exception is rethrown with the throw catchedException which resets the stack trace. That is bad but things are even worse because if previously lets say 5 exceptions did occur .NET will return only the first (innermost) exception. That does mean that we do not only loose the original call stack but all other exceptions and all data contained therein as well. It is a pity that MS does know about this and simply closes this issue as not important. Programmers will play a lot more around with threads than before thanks to TPL, PLINQ that do come with .NET 4. Multithreading is hyped quit a lot in the press and everybody wants to use threads. But if the .NET Framework makes it nearly impossible to track down the easiest UI multithreading issue I have a problem with that. The problem has been reported but obviously not been solved. .NET 4 Beta 2 did not have changed that dreaded GetBaseException call in MarshaledInvoke to return only the innermost exception of the complete exception stack. It is really time to fix this. WPF on the other hand does the right thing and wraps the exceptions inside a TargetInvocationException which makes much more sense. But Not everybody uses WPF for its daily work and Windows forms applications will still be used for a long time. Below is the code to repro the issues shown and how the exceptions can be rendered in a meaningful way. The default Exception.ToString implementation generates a hard to interpret stack if several nested exceptions did occur. using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using System.Threading; using System.Globalization; using System.Runtime.CompilerServices; namespace WindowsFormsApplication1 { public partial class AppForm : Form { enum CallMode { Direct = 0, BeginInvoke = 1, Invoke = 2 }; public AppForm() { InitializeComponent(); Thread.CurrentThread.CurrentUICulture = CultureInfo.InvariantCulture; Application.ThreadException += new System.Threading.ThreadExceptionEventHandler(Application_ThreadException); } void Application_ThreadException(object sender, System.Threading.ThreadExceptionEventArgs e) { cOutput.Text = PrintException(e.Exception, 0, null).ToString(); } private void cDirectUnhandled_Click(object sender, EventArgs e) { InvokingFunction(CallMode.Direct); } private void cDirectCall_Click(object sender, EventArgs e) { try { InvokingFunction(CallMode.Direct); } catch (Exception ex) { cOutput.Text = PrintException(ex, 0, null).ToString(); } } private void cInvoke_Click(object sender, EventArgs e) { InvokingFunction(CallMode.Invoke); } private void cBeginInvokeCall_Click(object sender, EventArgs e) { InvokingFunction(CallMode.BeginInvoke); } [MethodImpl(MethodImplOptions.NoInlining)] void InvokingFunction(CallMode mode) { switch (mode) { case CallMode.Direct: GenerateError(); break; case CallMode.Invoke: this.Invoke(new MethodInvoker(GenerateError)); break; case CallMode.BeginInvoke: IAsyncResult res = this.BeginInvoke(new MethodInvoker(GenerateError)); this.EndInvoke(res); break; } } [MethodImpl(MethodImplOptions.NoInlining)] void GenerateError() { F1(); } private void F1() { try { F2(); } catch (Exception ex) { throw new NotSupportedException("Outer Exception", ex); } } private void F2() { throw new NotImplementedException("Inner Exception"); } StringBuilder PrintException(Exception ex, int identLevel, StringBuilder sb) { StringBuilder builtStr = sb; if( builtStr == null ) builtStr = new StringBuilder(); if( ex == null ) return builtStr; WriteLine(builtStr, String.Format("{0}: {1}", ex.GetType().FullName, ex.Message), identLevel); WriteLine(builtStr, String.Format("StackTrace: {0}", ShortenStack(ex.StackTrace)), identLevel + 1); builtStr.AppendLine(); return PrintException(ex.InnerException, ++identLevel, builtStr); } void WriteLine(StringBuilder sb, string msg, int identLevel) { foreach (string trimmedLine in SplitToLines(msg) .Select( (line) => line.Trim()) ) { for (int i = 0; i < identLevel; i++) sb.Append('\t'); sb.Append(trimmedLine); sb.AppendLine(); } } string ShortenStack(string stack) { int nonAppFrames = 0; // Skip stack frames not part of our app but include two foreign frames and skip the rest // If our stack frame is encountered reset counter to 0 return SplitToLines(stack) .Where((line) => { nonAppFrames = line.Contains("WindowsFormsApplication1") ? 0 : nonAppFrames + 1; return nonAppFrames < 3; }) .Select((line) => line) .Aggregate("", (current, line) => current + line + Environment.NewLine); } static char[] NewLines = Environment.NewLine.ToCharArray(); string[] SplitToLines(string str) { return str.Split(NewLines, StringSplitOptions.RemoveEmptyEntries); } } }

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C# async and actors

- by Alex.Davies

If you read my last post about async, you might be wondering what drove me to write such odd code in the first place. The short answer is that .NET Demon is written using NAct Actors. Actors are an old idea, which I believe deserve a renaissance under C# 5. The idea is to isolate each stateful object so that only one thread has access to its state at any point in time. That much should be familiar, it's equivalent to traditional lock-based synchronization. The different part is that actors pass "messages" to each other rather than calling a method and waiting for it to return. By doing that, each thread can only ever be holding one lock. This completely eliminates deadlocks, my least favourite concurrency problem. Most people who use actors take this quite literally, and there are plenty of frameworks which help you to create message classes and loops which can receive the messages, inspect what type of message they are, and process them accordingly. But I write C# for a reason. Do I really have to choose between using actors and everything I love about object orientation in C#? Type safety Interfaces Inheritance Generics As it turns out, no. You don't need to choose between messages and method calls. A method call makes a perfectly good message, as long as you don't wait for it to return. This is where asynchonous methods come in. I have used NAct for a while to wrap my objects in a proxy layer. As long as I followed the rule that methods must always return void, NAct queued up the call for later, and immediately released my thread. When I needed to get information out of other actors, I could use EventHandlers and callbacks (continuation passing style, for any CS geeks reading), and NAct would call me back in my isolated thread without blocking the actor that raised the event. Using callbacks looks horrible though. To remind you: m_BuildControl.FilterEnabledForBuilding( projects, enabledProjects = m_OutOfDateProjectFinder.FilterNeedsBuilding( enabledProjects, newDirtyProjects = { ....... Which is why I'm really happy that NAct now supports async methods. Now, methods are allowed to return Task rather than just void. I can await those methods, and C# 5 will turn the rest of my method into a continuation for me. NAct will run the other method in the other actor's context, but will make sure that when my method resumes, we're back in my context. Neither actor was ever blocked waiting for the other one. Apart from when they were actually busy doing something, they were responsive to concurrent messages from other sources. To be fair, you could use async methods with lock statements to achieve exactly the same thing, but it's ugly. Here's a realistic example of an object that has a queue of data that gets passed to another object to be processed: class QueueProcessor { private readonly ItemProcessor m_ItemProcessor = ... private readonly object m_Sync = new object(); private Queue<object> m_DataQueue = ... private List<object> m_Results = ... public async Task ProcessOne() { object data = null; lock (m_Sync) { data = m_DataQueue.Dequeue(); } var processedData = await m_ItemProcessor.ProcessData(data); lock (m_Sync) { m_Results.Add(processedData); } } } We needed to write two lock blocks, one to get the data to process, one to store the result. The worrying part is how easily we could have forgotten one of the locks. Compare that to the version using NAct: class QueueProcessorActor : IActor { private readonly ItemProcessor m_ItemProcessor = ... private Queue<object> m_DataQueue = ... private List<object> m_Results = ... public async Task ProcessOne() { // We are an actor, it's always thread-safe to access our private fields var data = m_DataQueue.Dequeue(); var processedData = await m_ItemProcessor.ProcessData(data); m_Results.Add(processedData); } } You don't have to explicitly lock anywhere, NAct ensures that your code will only ever run on one thread, because it's an actor. Either way, async is definitely better than traditional synchronous code. Here's a diagram of what a typical synchronous implementation might do: The left side shows what is running on the thread that has the lock required to access the QueueProcessor's data. The red section is where that lock is held, but doesn't need to be. Contrast that with the async version we wrote above: Here, the lock is released in the middle. The QueueProcessor is free to do something else. Most importantly, even if the ItemProcessor sometimes calls the QueueProcessor, they can never deadlock waiting for each other. So I thoroughly recommend you use async for all code that has to wait a while for things. And if you find yourself writing lots of lock statements, think about using actors as well. Using actors and async together really takes the misery out of concurrent programming.

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