Problem with EJB 3.0 Specs Intercptors ......

[Nitin Takale]

Hi All,

According to EJB 3.0 Specification core contracts and requirements page no..305 if we've to specify lifecycle callback methods which are written inside an interceptor class for a session bean or mdb using Deployment descriptors then ... we've to use post-construct, pre-destroy, post-activate, and pre-passivate elements.

But when I saw the schema file of ejb-jar.xml for ejb3.0 I did not get these elements or any attribute of such type.

So can you please guide me regarding how do I specify the interceptor class which contains lifecycle callback methods using deployment descriptor.

See.. I don't want to write any lifecycle callback methods inside bean class I want to write it inside interceptor class. And I don't want to use Interceptors annotation on my bean class. I want to specify the interceptor using deployment descriptor.

So how to do it ???

thanks

Nitin

[Sergio Tridente]

Hi Nitin,

I understand what you say. Well, in fact I was able to find the around-invoke , pre-passivate and post-activate elements of the deployment descriptor: take a look at page 536. It is defined so that they may be specified inside sessionType or interceptorType elements. But the post-construct and pre-destroy are nowhere to be found.

In fact, inside the definition of the interceptorType element there is a documentation element that reads:

The interceptorType element declares information about a single interceptor class. It consists of :
- An optional description.
- The fully-qualified name of the interceptor class.
- An optional list of around invoke methods declared on the interceptor class and/or its super-classes.
- An optional list environment dependencies for the interceptor class and/or its super-classes.
- An optional list of post-activate methods declared on the interceptor class and/or its super-classes.
- An optional list of pre-passivate methods declared on the interceptor class and/or its super-classes.

Again, the post-construct and pre-destroy elements are not mentioned.


This is not what the specification states in section 12.4:

If the deployment descriptor is used to define interceptors, the post-construct, pre-destroy, post-activate, and pre-passivate elements are used.

Furthermore, section 12.8.1 makes the following "mistake":

The interceptor methods are specified by using the around-invoke, pre-construct, post-destroy, pre-passivate, and post-activate elements.

Note it talks about pre-construct (vs. post-construct) and post-destroy (vs. pre-destroy).

This is confusing.
[ September 01, 2008: Message edited by: Sergio Tridente ]

[Nitin Takale]

Thanks....Sergio Tridente

But I got the solution for the same... I used Eclipse Ganymede and here goes the ejb-jar.xml of it.....


<?xml version="1.0" encoding="UTF-8"?>
<ejb-jar version="3.0" xmlns="http://java.sun.com/xml/ns/javaee"; xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"; xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/ejb-jar_3_0.xsd">
<enterprise-beans>
<session>
<ejb-name>WorkerBean</ejb-name>
<business-remote>com.seed.WorkerBeanRemote</business-remote>
<session-type>Stateless</session-type>
<transaction-type>Container</transaction-type>
</session>

</enterprise-beans>

<interceptors>

<interceptor>

<interceptor-class>com.seed.interceptor.LifeCycleInterceptor</interceptor-class>

<post-construct>

<lifecycle-callback-method>oneMoreCreate</lifecycle-callback-method>
</post-construct>
<pre-destroy>

<lifecycle-callback-method>oneMoreDestroy</lifecycle-callback-method>
</pre-destroy>
</interceptor>
</interceptors>
<assembly-descriptor>

<interceptor-binding>

<ejb-name>WorkerBean</ejb-name>

<interceptor-class>com.seed.interceptor.LifeCycleInterceptor</interceptor-class>

</interceptor-binding></assembly-descriptor>

</ejb-jar>


Well that's the way it is ....

bye

nitin

[Tomaszz Lewandowski]

Hello,

<post-construct> and <pre-destroy> elements are in jndiEnvironmentRefsGroup in interceptorType, so the spec is correct, you can use these as subelements of element "interceptor" and "session".