Creating an admin application for phpBB using GWT and JPA

The Result

We are ready and push Finish. A lot of new classes appear in the package:

Right-click on User and select Show in Class Diagram. Create a new class diagram and enter a name.

That's a big class! But it looks ok.

Now, where is the Java code? It's not generated yet. Save the class diagram to generate all the code. (You can also right-click on the HiberObjects icon and Save All.)

Let's have a look at the generated code:

@javax.persistence.Entity @javax.persistence.Table(name="phpbb_users") public class User implements java.io.Serializable { ... /** * @generated */ @javax.persistence.Id @javax.persistence.Column(name = "user_id", length = 8, nullable = false) public int getId() { return this.id; } /** * @generated */ @javax.persistence.ManyToOne(optional = false) @javax.persistence.JoinColumn(name = "group_id", nullable = false) public Group getGroup() { return this.group; } /** * @generated */ public void setGroup(Group group) { this.group = group; } ... @javax.persistence.Entity @javax.persistence.Table(name="phpbb_groups") public class Group implements java.io.Serializable { ... /** * @generated */ @javax.persistence.OneToMany(mappedBy = "group") public java.util.Set<User> getUser() { return this.user; } /** * @generated */ public void setUser(java.util.Set<User> user) { this.user = user; } /** * @generated */ public void addUser(User user) { getUser().add(user); } /** * @generated */ public void removeUser(User user) { getUser().remove(user); }

This looks ok.

Generated Id

JPA can generate id values automatically when we insert new objects in the database. That can be accomplished with the @GeneratedValue annotation. In the phpBB3 database, all id columns use MySQL auto_increment, so @GeneratedValue will work. If it weren't for this, we might have to generate id's manually, which is a pain.

So, let's run the import wizard once more, modify the variableAnnotationsId method and push Update Method:

Push Finish, and then Save All on the HiberObjects icon or Save in a diagram.

The Java code now becomes:

   /**
    * @generated
    */
   @javax.persistence.Id
   @javax.persistence.Column(name="user_id", length=8, nullable=false)
   @javax.persistence.GeneratedValue(strategy=javax.persistence.GenerationType.AUTO)
   public int getId() {
      return this.id;
   }

This is what we want.

Next: Create DAO

HiberObjects

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The Result

Generated Id