docs/callbacks.adoc

= Callbacks
:index-group: Unrevised
:jbake-date: 2018-12-05
:jbake-type: page
:jbake-status: published

Correct usage of PostConstruct, PreDestroy, PrePassivate, PostActivate,
and AroundInvoke for EJBs and Interceptors.

For Stateful, Stateless, and MessageDriven, the syntax is as follows:

* @PostConstruct <any-scope> void <method-name>()
* @PreDestroy <any-scope> void <method-name>()
* @PrePassivate <any-scope> void <method-name>()
* @PostActivate <any-scope> void <method-name>()

For an Interceptor, the syntax includes InvocationContext as follows:

* @PostConstruct <any-scope> void <method-name>(InvocationContext)
* @PreDestroy <any-scope> void <method-name>(InvocationContext)
* @PrePassivate <any-scope> void <method-name>(InvocationContext)
* @PostActivate <any-scope> void &ltmethod-name>(InvocationContext)

The AroundInvoke syntax for an EJB or Interceptor is the same:

* @AroundInvoke <any-scope> Object <method-name>(InvocationContext)
throws Exception

== Stateless

[source,java]
----
import javax.ejb.Stateless;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.interceptor.AroundInvoke;
import javax.interceptor.InvocationContext;

@Stateless
public class MyStatelessBean implements  MyBusinessInterface  {

    @PostConstruct
    public void constructed(){

    }

    @PreDestroy
    public void destroy(){

    }

    @AroundInvoke
    public Object invoke(InvocationContext invocationContext) throws Exception {
    return invocationContext.proceed();
    }
}
----

== Stateful

[source,java]
----
import javax.ejb.Stateful;
import javax.ejb.PostActivate;
import javax.ejb.PrePassivate;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.interceptor.AroundInvoke;
import javax.interceptor.InvocationContext;

@Stateful
public class MyStatefulBean implements  MyBusinessInterface  {

    @PostConstruct
    public void constructed(){

    }

    @PreDestroy
    public void destroy(){

    }

    @AroundInvoke
    public Object invoke(InvocationContext invocationContext) throws Exception {
          return invocationContext.proceed();
    }

    @PostActivate
    public void activated(){

    }

    @PrePassivate
    public void passivate(){

    }
}
----

== MessageDriven

[source,java]
----
import javax.ejb.MessageDriven;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.interceptor.AroundInvoke;
import javax.interceptor.InvocationContext;

@MessageDriven
public class MyMessageDrivenBean implements  MyListenerInterface  {

    @PostConstruct
    public void constructed(){

    }

    @PreDestroy
    public void destroy(){

    }

    @AroundInvoke
    public Object invoke(InvocationContext invocationContext) throws Exception {
          return invocationContext.proceed();
    }
}
----

== Interceptor

[source,java]
----
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.interceptor.InvocationContext;
import javax.interceptor.AroundInvoke;
import javax.ejb.PostActivate;
import javax.ejb.PrePassivate;

public class MyInterceptor {

    @PostConstruct
    public void constructed(InvocationContext invocationContext){

    }

    @PreDestroy
    public void destroy(InvocationContext invocationContext){

    }

    @AroundInvoke
    public Object invoke(InvocationContext invocationContext) throws Exception {
        return invocationContext.proceed();
    }

    @PostActivate
    public void activated(InvocationContext invocationContext){

    }

    @PrePassivate
    public void passivate(InvocationContext invocationContext){

    }
}
----