Implements Runnable over Extends Thread with EJB

Question

Let's say the class MyCoolProcess has the logic of my app which is needed to be called in it's own thread. We'll create a thread, call it and continue with the application.
This class is a EJB; annotated with @Stateless

Now we have the MyController class; which is going to call a new thread.

Code:

public class MyController {

  @EJB
  MyCoolProcess p;

  public Response foo() {
    Thread t = new Thread() {
      public void run() {
        p.run();
      }
    };
    t.start();
    // continues ...
  }

 }

---

@Stateless
public class MyCoolProcess {

  public void run() {
    // heavy task
  }
}

That is working fine; the point is... before that solution I've tried with the Runnable interface. Which was I wanted at first time. The approach would be:

public class MyController {

  @EJB
  MyCoolProcess p;

  public Response foo() {
    Thread t = new Thread(p);
    t.start();
    // continues ...
  }

 }

---

@Stateless
public class MyCoolProcess implements Runnable {

  @Override
  public void run() {
    // heavy task
  }
}

That doesn't work. Actually, the server cannot start. Crashes trying to inject the dependencies. I'm not be able to implement the interface Runnable if I'm a EJB isn't it? WHY

And... is there any way to do the Runnable way instead the anonymous class?

Answer 1

From the EJB spec:

The enterprise bean must not attempt to manage threads. The enterprise bean must not attempt to start, stop, suspend, or resume a thread, or to change a thread’s priority or name. The enterprise bean must not attempt to manage thread groups.

See Adam's Blog.