EJB2.0 with OpenEJB: Stateless Session Bean in Action

I am taking SCBCD5.0 certification soon. Right now, I am going over some EJB2.0 materials before taking on EJB3.0. I generally know EJB3.0 but never had grasped the fundamentals of EJB2.0. Mastering EJB2.0 would demystify EJB3.0.

I am writing a two-part blog about an EJB2.0 application running on a stand-alone OpenEJB server which also involves a remote Java client application running on a Linux machine. This is the first part.

Software required (or were used for this blog):

OpenEJB 3.1.4
JDK1.6 Update 21
Eclipse Ganymede (optional)
VMWare 3.0.1
Ubuntu 10.10 (running as a virtual machine)

Create the interfaces

package com.ejb2;
import java.rmi.RemoteException;
import javax.ejb.EJBObject;
public interface Advice extends EJBObject {
    public String getAdvice() throws RemoteException;
}

package com.ejb2;

import java.rmi.RemoteException;

import javax.ejb.EJBObject;

public interface Advice extends EJBObject {

public String getAdvice() throws RemoteException;

}

package com.ejb2;
import java.rmi.RemoteException;
import javax.ejb.CreateException;
import javax.ejb.EJBHome;

public interface AdviceHome extends EJBHome {
    public Advice create() throws CreateException, RemoteException;
}

package com.ejb2;

import java.rmi.RemoteException;

import javax.ejb.CreateException;

import javax.ejb.EJBHome;

public interface AdviceHome extends EJBHome {

public Advice create() throws CreateException, RemoteException;

}

Create the your session bean

package com.ejb2;
import java.rmi.RemoteException;
import javax.ejb.*;

public class AdviceBean implements SessionBean {
    public void ejbActivate() throws EJBException, RemoteException { }
    public void ejbPassivate() throws EJBException, RemoteException { }
    public void ejbRemove() throws EJBException, RemoteException { }
    public void setSessionContext(SessionContext arg0)
        throws EJBException,
            RemoteException {}
    public String getAdvice() {
        return "advice that";
    }
}

package com.ejb2;

import java.rmi.RemoteException;

import javax.ejb.*;

public class AdviceBean implements SessionBean {

public void ejbActivate() throws EJBException, RemoteException { }

public void ejbPassivate() throws EJBException, RemoteException { }

public void ejbRemove() throws EJBException, RemoteException { }

public void setSessionContext(SessionContext arg0)

throws EJBException,

RemoteException {}

public String getAdvice() {

return "advice that";

}

NOTE: In order to successfully build the project in Eclipse, you ought to include javaee-api-5.0-3.jar in the class path.

Create ejb-jar.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE ejb-jar PUBLIC "-//Sun Microsystems, Inc.//DTD Enterprise JavaBeans 2.0//EN"
"http://java.sun.com/dtd/ejb-jar_2_0.dtd">
<ejb-jar>
    <enterprise-beans>
    <session>
        <home>com.ejb2.AdviceHome</home>
        <ejb-name>AdviceBean</ejb-name>
        <remote>com.ejb2.Advice</remote>
        <ejb-class>com.ejb2.AdviceBean</ejb-class>
        <session-type>Stateless</session-type>
        <transaction-type>Bean</transaction-type>
        <security-identity>
            <description></description>
            <use-caller-identity></use-caller-identity>
        </security-identity>
    </session>
    </enterprise-beans>
</ejb-jar>