"richie-lea" wrote:
There is a java.lang.ClassCastException: ejb.persistence.User.

My servlet code is:

private void showUser(HttpServletRequest request,
 HttpServletResponse response) {
 try {
 InitialContext ctx = new InitialContext();
 userSession = (userSession) ctx.lookup("userSessionBean/local");
 } catch (Exception e) {
 e.printStackTrace();
 }

 Collection<User> auser = userSession.getUsers();
 if (auser != null)
 for (User user : auser) {
 System.out.println("User name : " + user.getName());
 System.out.println("User id : " + user.getId());
 System.out.println("User mgs : " + user.getMessage());
 }
 }

userSessionBean/local getUsers method code is:

 public Collection<User> getUsers() {
 // TODO Auto-generated method stub
 return em.createQuery("from User u").getResultList();
 }

My ejb.persistence.User class is:

package ejb.persistence;

import javax.persistence.*;

@Entity
@Table(name = "user")
public class User {
 private String name;

 private int id;

 private String message;

 public User() { }

 public User(String name, String message) {
 this.name = name;
 this.message = message;
 }

 @Id
 @GeneratedValue
 public int getId() {
 return id;
 }

 public void setId(int id) {
 this.id = id;
 }

 public String getMessage() {
 return message;
 }

 public void setMessage(String message) {
 this.message = message;
 }

 public String getName() {
 return name;
 }

 public void setName(String name) {
 this.name = name;
 }
}

Log msg:

06:43:44,937 ERROR [[ejb_servlet]] Servlet.service() for servlet ejb_servlet threw exception
java.lang.ClassCastException: ejb.persistence.User
 at servlet.ejb_servlet.showUser(ejb_servlet.java:51)
 at servlet.ejb_servlet.doGet(ejb_servlet.java:87)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:697)
 .....

Sorry for the long post, hope you're still with me. My questions is:
Why did the ClassCastException occured? What's wrong?

I changed the servlet :

private void showUser(HttpServletRequest request,
 HttpServletResponse response) {
 try {
 InitialContext ctx = new InitialContext();
 userSession = (userSession) ctx.lookup("userSessionBean/local");
 } catch (Exception e) {
 e.printStackTrace();
 }

 Collection<User> auser = userSession.getUsers();
 System.out.println(auser);

 if (auser != null)
 for (User user : auser) {
 System.out.println("User name : " + user.getName());
 System.out.println("User id : " + user.getId());
 System.out.println("User mgs : " + user.getMessage());
 }
 }

07:09:51,546 INFO [STDOUT] [ejb.persistence.User@200470, ejb.persistence.User@3813c, ejb.persistence.User@19b32e, ejb.persistence.User@1429c57, ejb.persistence.User@264dd8, ejb.persistence.User@c0c6f6, ejb.persistence.User@46752d, ejb.persistence.User@1b71c12]
07:09:51,546 ERROR [[ejb_servlet]] Servlet.service() for servlet ejb_servlet threw exception
java.lang.ClassCastException: ejb.persistence.User
 at servlet.ejb_servlet.showUser(ejb_servlet.java:53)
 at servlet.ejb_servlet.doGet(ejb_servlet.java:89)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:697)