实体没有表单对象所需的字段

Question

I have Entity:

public class User {
  private Long id;
  private String name;
  private String lastName;
  private String email;
  private String password;

  // getters and setters
}

I would like to use it as a Form Backing Object in presentation layer, but it doesn't have fields that I need. In this case I need repeatedPassword field.

What is the best approach to this problem without modifying entity class?
Should I extend this entity class and add needed fields?
Should I create new class which has a field private User user; with getter and setter?
Should I copy/paste this class and then add needed fields?

Answer 1

Three different solutions:

• The usual way of dealing with a situation where the input fields on a form don't match up with an entity is to use a Command object (this is what Sotirios was advocating in the comments). Making a separate object for this that is not an entity is much less confusing than extending the entity to add something unrelated to persistence.

• It be argued in this case there's no need to pass the repeatedPassword field back to the server, the validation could be done entirely on the client, and the input field doesn't need to be bound to a Java pojo at all.

• If you really want to pass the repeatedPassword back to the server (so you can do all your validation on the server-- although the repeated password is more of a user convenience than real validation), then you could add the repeatedPassword field to the User entity with a @Transient declaration.