Just a simple example but got NonUniqueObjectExcept

cn1h · **Joined:** Thu Aug 27, 2009 10:35 am **Posts:** 6

Code:

// persistence context started

         User newUser = new User(userName, Encoder.encodePassword(password));
         this.session.save(newUser);
         Type newTypeIn = new Type("new type", newUser, 'I');
         this.session.save(newTypeIn);
         Type newTypeOut = new Type("new type", newUser, 'O');
         this.session.save(newTypeOut);

// transaction commit and persistence context end

Then got a Exception:org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session: [entities.Type#0]

I read the book <<Java Persistence With Hibernate>>, It said, this Exception is because the detached Object was reattached in Session but there was already another Object with the same identifier in the Session. The solution is use session.merge() instead of session.update(). But that's not my Situation, my problem is about new created Object, so what should I do?

Thanks!

Cameron McKenzie · **Posted:** Thu Aug 27, 2009 12:25 pm

What is the primary key for NewType?

cn1h · **Joined:** Thu Aug 27, 2009 10:35 am **Posts:** 6

Cameron McKenzie wrote:

What is the primary key for NewType?

int id, it's an auto generated field in database

Code:

public class Type {


   @Id
   private int id;
   private String name;
   @JoinColumn(name="username", referencedColumnName="name")
   private User user;
   private char type;  // 'I'ncome or 'O'utput
   
   public Type() {
      
   }
   
   public Type(String name, User user, char type) {
      this.setName(name);
      this.setUser(user);
      this.setType(type);
   }
......

Cameron McKenzie · **Posted:** Thu Aug 27, 2009 6:21 pm

Well, it looks like your save isn't giving these entities new identifiers.

Quote:

[entities.Type#0]

That tells me both entities have an identifier of zero. The save method returns the primary key. Maybe you can log it and see if you're getting a non-zero number.

Have you overridden the .equals method? That might help?