weblogic下的一个简单ejb例子

HelloWorld----------
public interface HelloWorld extends EJBObject {
public String getHello() throws java.rmi.RemoteException;
}
HelloWorldHome-------
public interface HelloWorldHome extends EJBHome{
HelloWorld create() throws CreateException, RemoteException;
}
HelloWorldImpl-------
public class HelloWorldImpl implements SessionBean{
private static final long serialVersionUID = 3159210541480135603L;

public String getHello() throws EJBException, RemoteException {
  System.out.println("getHello()");
  return "hello,world";
}

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  void  ejbCreate()  throws   javax.ejb.CreateException{};

}
ejb-jar.xml----
<?xml version="1.0" encoding="GB2312"?>
<!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>
<display-name>First</display-name>
<enterprise-beans>
  <session>
   <ejb-name>FirstEjb</ejb-name>
   <home>com.ejb.HelloWorldHome</home><!--主接口-->
   <remote>com.ejb.HelloWorld</remote><!--组件接口-->
   <ejb-class>com.ejb.HelloWorldImpl</ejb-class><!--组件接口的实现-->
   <session-type>Stateless</session-type>
   <transaction-type>Bean</transaction-type>
  </session>
</enterprise-beans>
</ejb-jar>
weblogic-ejb-jar.xml-------
<?xml version="1.0" encoding="GB2312"?>
<!DOCTYPE weblogic-ejb-jar PUBLIC '-//BEA Systems, Inc.//DTD WebLogic 8.1.0 EJB//EN' 'http://www.bea.com/servers/wls810/dtd/weblogic-ejb-jar.dtd'>
<weblogic-ejb-jar>
  <weblogic-enterprise-bean>
    <ejb-name >FirstEjb</ejb-name>
    <stateless-session-descriptor>
      <pool>
      </pool>
      <stateless-clustering>
      </stateless-clustering>
    </stateless-session-descriptor>
    <transaction-descriptor>
    </transaction-descriptor>
    <jndi-name >FirstEjb</jndi-name>
  </weblogic-enterprise-bean>
</weblogic-ejb-jar>

希望听到优缺点，性能评估方面的信息。也就是选择这个的理论基础（要有数据证明）。