Wednesday, April 11, 2012

How to invoke local EJB session beans in WebLogic

Sometimes you may have a need to invoke a LOCAL EJB session beans in a normal java class, for example, Business Delegate class, you can use ServiceLocator to locate a local EJB session bean proxy by JNDI name. Even though it is relatively easy to do so for a REMOTE EJB session bean by using the value of  'name' or 'mappedName' in the bean class definition, it is a little tricky for LOCAL session beans.

Here is what you need to do.

For exampe:

Here is an interface:

package  com.play;

@Local
public interface PlayFacadeInf {
     public void play(String var);
}


Here is the implementation bean class.

package  com.play;

@Stateless
public class  PlayFacadeImpl implements  PlayFacadeInf {
     public void play(String var) {
          //...do somthing
    }
}


Here is the part of the ejb-jar.xml


display-name>myEJB </display-name>
  <enterprise-beans>
<session>
<ejb-name> PlayFacadeImpl</ejb-name>
<ejb-class>com.play.PlayFacadeImpl</ejb-class>
<ejb-local-ref>
<ejb-ref-name>ejb/PlayFacadeInf</ejb-ref-name>
<ejb-ref-type>Session</ejb-ref-type>
<local>com.play.PlayFacadeInf</local>
</ejb-local-ref>
</session>
   </enterprise-beans>

Here is part of web.xml


<ejb-local-ref>
<ejb-ref-name>ejb/PlayFacadeInf</ejb-ref-name>
<ejb-ref-type>Session</ejb-ref-type>
<local>com.play.PlayFacadeInf</local>
</ejb-local-ref>

Here is part of the ServiceLocator.java



private static InitialContext ctx = null;
static {
try {
ctx = new InitialContext();
}
catch (NamingException e) {
//... throw some exception
}
}

private static InitialContext getInitialContext() throws NamingException{
return ctx;
}


public static  PlayFacadeInf  getPlayFacade() throws NamingException {

PlayFacadeInf     playFacadeInf   = null;

playFacadeInf     = ( PlayFacadeInf )            
                       ServiceLocator.getInitialContext().lookup("java:/comp/env/ejb/PlayFacadeInf");

return  playFacadeInf;
}

Then any normal java class can use the ServiceLocator to get hold of the local ejb session bean proxy.

1 comment:

  1. I am using weblogic 10.3.5 and I don't have web.xml file. Where should I add the web.xml part.

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