back group threads without user interactions

[hztiger]

I have some back group threads to run when application starts up. These threads are moving from old code and are doing a lot of works without user interactions. So, I think there is no seam event here. How can I use seam context, especially entity manager?
  Thanks in advance!

Below is my sample code.

public class MyThread extends Thread {
     @Override
     public void run() {
     //TODO:
     //there is not seam context here. how can I use entity manager here ? 
     
     for(;;){
          //do routine job .....
     }
     
     }
}


@Scope(ScopeType.APPLICATION)
@Name("backgroupPool")
@Startup
public class BackgroupPool extends Thread {

/*
     EntityManagerFactory entityManagerFactory;
     public EntityManagerFactory getEntityManagerFactory() {
          org.jboss.seam.contexts.Context applicationContext = (org.jboss.seam.contexts.Context) Contexts
                    .getApplicationContext();
          if (applicationContext != null) {
               org.jboss.seam.persistence.EntityManagerFactory entityManagerFactory3 = (org.jboss.seam.persistence.EntityManagerFactory) applicationContext
                         .get("dbTestEntityManagerFactory");
               if (entityManagerFactory3 != null) {

                    entityManagerFactory = entityManagerFactory3
                              .getEntityManagerFactory();

               }
          }

     }
*/     
     @Override
     public void run() {

          for (int i = 0; i < 10; i++) {
               MyThread thread = new MyThread();
               thread.start();
          }

     }
     
     @Observer("org.jboss.seam.postInitialization")
     public void init() {
          //getEntityManagerFactory
          this.startup();


     }                                   

[germanescobar]

Use Lifecycle.beginCall() at the start of each thread and Lifecycle.endCall() at the end. Then you can have access to the contexts.

Hope it helps!

[kapitanpetko]

German Escobar wrote on Dec 21, 2009 03:39:


Use Lifecycle.beginCall() at the start of each thread and Lifecycle.endCall() at the end. Then you can have access to the contexts.

That would probably work, but you should consider using asynchronous methods instead of 'raw' threads. That gives you thread pooling and management for free. It is also integrated with Seam, so you get access to contexts (application and event only)..

[hztiger]

Thanks for replying, MyThread must be Seam componet if using Lifecycle.beginCall(). But MyThread is dynamice created, and have many instance. I think this method does not work.

[hztiger]

Thanks for replying. But MyThread is dynamice created, and have many instances. Can you give me any examples?
  Backgroup thread is widely used. And many should be integrated into seam. Can some one give me any such example.

Nikolay Elenkov wrote on Dec 21, 2009 07:22:

German Escobar wrote on Dec 21, 2009 03:39:


Use Lifecycle.beginCall() at the start of each thread and Lifecycle.endCall() at the end. Then you can have access to the contexts.

That would probably work, but you should consider using asynchronous methods instead of 'raw' threads. That gives you thread pooling and management for free. It is also integrated with Seam, so you get access to contexts (application and event only)..

Click HELP for text formatting instructions. Then edit this text and check the preview.

[kapitanpetko]

tiger zhao wrote on Dec 23, 2009 03:56:


Thanks for replying. But MyThread is dynamice created, and have many instances. Can you give me any examples?
  Backgroup thread is widely used. And many should be integrated into seam. Can some one give me any such example.

Read about it here: Asynchronicity

[hztiger]

Nikolay Elenkov wrote on Dec 24, 2009 03:36:

tiger zhao wrote on Dec 23, 2009 03:56:


Thanks for replying. But MyThread is dynamice created, and have many instances. Can you give me any examples?
  Backgroup thread is widely used. And many should be integrated into seam. Can some one give me any such example.

Read about it here: Asynchronicity

As to a single thread, it works. But There are many same thread. I have not seen such examples before. Really need help!

[kapitanpetko]

If you call an asynchronous method multiple times that will create multiple background threads.