Help me in Stateless & Stateful Bean

Question

hi,
I'm trying to understand to difference between the stateless and stateful bean. I had created an simple application to test it. But both the beans seems to work in the same way. Could some one explain me with an example the difference between the stateful and stateless bean ...
I'm using J2EE Reference Implementation and Deploytool .
Please help me .. Urgent ....
Cheers !!!
Prabs

Answer 1

Thanks!!
The State Session Bean tries to hold data , even after the client has finished execution. Moreover, the ejbCreate() get fired only once and not for different client.
Is there anything that I should do to make it stateless.
this is my code
Session Bean
import javax.ejb.SessionBean;
import javax.ejb.SessionContext;
import java.util.*;
public class cartEJB implements SessionBean {
     private Map m;
     public cartEJB() { }
     public void ejbCreate() {
     m = new HashMap();
     System.out.println("ejbCreate()");
     public void ejbActivate() { }
     public void ejbPassivate() { }
     public void ejbRemove() { }     
     public void setSessionContext(SessionContext sc) { }
     public void addCart(String product, String price) {
     System.out.println("Its here Man 1");
     m.put(product, price);
     public void showCart() {
          System.out.println("Its here Man 2");
          Set s = m.entrySet();
          Iterator it = s.iterator();
          while(it.hasNext()) {
               System.out.println(it.next());
REMOTE
import javax.ejb.EJBObject;
import java.rmi.RemoteException;
public interface cart extends EJBObject {
     public void addCart(String product , String price) throws RemoteException;
     public void showCart() throws RemoteException;
HOME
import javax.ejb.EJBHome;
import java.rmi.RemoteException;
import javax.ejb.CreateException;
public interface cartHome extends EJBHome {
     public cart create() throws CreateException, RemoteException;
client application is an web based application ..
Client code. ... (jsp:useBean)
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.rmi.PortableRemoteObject;
import javax.servlet.http.*;
public class cartJSP implements HttpSessionBindingListener{
     String Product = new String();
     String Price = new String();
     HttpSession session;
     public cartJSP() {
     public void setProduct(String p){
          this.Product = p;
     public void setPrice(String price) {
          this.Price=price;
     public String getPrice() {
          return Price;
     public String getProduct() {
          return Product;
     public void addIt(String product , String price ) {
     try {
          System.out.println("Comes here");
          Context ic = new InitialContext();
          Object objref = (Object)ic.lookup("ejb/cartJNDI");
          cartHome home = (cartHome)PortableRemoteObject.narrow(objref, cartHome.class);
          cart remote = home.create();          
          remote.addCart(product, price);
          System.out.println("Comes here");
          remote.showCart();     
     catch(Exception e) {
          e.printStackTrace();
     public void showIt() {
     try {
          Context ic = new InitialContext();
          Object objref = (Object)ic.lookup("ejb/cartJNDI");
          cartHome home = (cartHome)PortableRemoteObject.narrow(objref, cartHome.class);
          cart remote = home.create();
          remote.showCart();          
          System.out.println("Comes here 1");
     catch(Exception e) {
          e.printStackTrace();
     public void valueBound(HttpSessionBindingEvent e) {
          session = e.getSession();
          session.setMaxInactiveInterval(60);
          System.out.println("Value Bound");
     public void valueUnbound(HttpSessionBindingEvent e) {
          System.out.println("Value UnBound");
I'm using J2EE RI 1.3 and I'm deploying components using deploytool.
Please help me,
Check the code is wrong or is it a bug in the EJB container.
regards
prabu.