Stateful session bean calling @remove method from client

[Lalit mishra]

Hi all,
How do we call the @remove method from ejb client. A code snippet would be a great help.

Thanks,
Lalit

[Sai Surya]

Lalit mishra wrote:Hi all,
How do we call the @remove method from ejb client. A code snippet would be a great help.

Thanks,
Lalit

Hi Lalit,

We will call any method of Statefull session bean in the normal way (like POJO) The only thing is, method is marked with @Remove annotation in order to indicate the container that workflow ends after calling this method. Once method with @Remove executes the container will remove the Stateful bean instance.

Hope you understood.

[SampathKumar chinnadurai]

Hi Lalit,

We can't directly call the @Remove annotation from EJB client .we have to call the @Remove tagged business method from the client.

The @Remove annotation is used with a method to inform the container that the client no longer needs a session and that the session should be destroyed. This annotation is important, as it is the only way to request the container that the session should end. If the remove method is not used, the session will have to be timed out before it can be destroyed by itself. If stateful session bean instances are not removed when they are no longer needed, the number of inactive instances will keep on incrementing and will waste memory and CPU cycles. The syntax for declaring a method with the @Remove annotation is as follows:

  
@Stateful
public class EmployeeBean implements EmployeeOrder {
   //More code here
   @Remove
   public Long confirmOrder() {
      //Code for instance removal
   }
  

[Lalit mishra]

Thank you guys

[Vivek Punekar]

I am doing exactly this. Calling the @Remove and @Destroy annotated method from client but still I can see the SFSB hanging around in JProfiler.

I will highly appreciate any help, suggestion.

Thanks.

[Vivek Punekar]

BTW, I have also tried nullifying the EJB reference. Still it doesn't work.

Thanks.

[Mihai Radulescu]

Hi

As far as I know this measure makes the bean eligible for garbage collector, this does not means that the bean is also "garbeged" on the moment.
In most of the times the profilers have some ways to force the cg to occurs - but this is to profiler specific.

Regards
M

[Vivek Punekar]

Thanks for the reply.

I did use the force GC option on Profiler but it still doesnt cleanup the bean.

Thanks,
Vivek

[Vivek Punekar]

In fact I tried creating so many instances of the EJBs and everytime calling the @Remove method. Hundreds of instances were created and the server went OutOfMemory finally. But still the EJBs were hanging around.

Any clues?

Thanks in advance.

[Maneesh Godbole]

Vivek JavaRancher wrote:

Please check your private messages for an important administrative matter.

[Vivek Punekar]

My mistake. I had not deployed the changes correctly. Calling the method with @Remove does remove the EJB and its fundamentally correct.

Whats the difference between @Destroy and @Remove? Are both of them needed for Seam component which is an EJB as well?

Thanks.

[nitin pokhriyal]

If i am not wrong then

For @remove see comments above of SampathKumar chinnadurai
for @Destroy : Specifies that the method should be called when the context ends and its context variables are destroyed. Note that create methods are only supported for JavaBeans and stateful session beans.
Note that all stateful session bean components must define a method annotated @Destroy @Remove in order to guarantee destruction of the stateful bean when a context ends.
Destroy methods should be used only for cleanup. Seam catches, logs and swallows any exception that propagates out of a destroy method. Looks to me that either container removes bean or by @remove on method both calls destroy for cleanup.

anybody correct me if i am wrong.

[Mihai Radulescu]

Hi

Is @Destroy is a ejb annotation ? I am afraid that this is something jBoss specific.

Regards,
Mihai

[nitin pokhriyal]

My bad. yes you are correct it is in Jboss seams

[Mihai Radulescu]

Hi

Yes, this is true, Seam has a @Destroy - life cycle callback.

Regards,
Mihai

[Vivek Punekar]

Hello,

So does it mean we need both @Remove and @Destroy for a Seam component which is EJB also?

Thanks,
Vivek

[Mihai Radulescu]

Hi.

That's depends what are you doing.
I tend to answer no to this question.
The @Remove cleans marks the ends of a stateful bean.
The @Destroy is jBoss/seam specific and it represents the finalisation for a seam component. More precisely before the seam component (which is a bean) pull out from the context this method is call.

Regards,
Mihai

[Klaus Schultz]

Taking beside Seam: in EJB you should differentiate between the concept of a @Remove annotated method of stateful session bean, which will be called by the client, and the concept of a @PreDestroy annotated method, a lifecycle callback method called by the container. I think the Destroy method of Seam resembles the PreDestroy in EJB.

Klaus