Question

I have an User entity:

@Entity
@Table(name = "user")
public class User implements Serializable{
private enum Sex {MALE, FEMALE};

@Id @GeneratedValue
private Long id;
@NotNull
private String name;
    @NotNull
    private String password;
}

Controller:

@Controller
public class HomeController {
@RequestMapping("/addUser")
public String showHomePage(Map<String, Object> map) {
    map.put("user", new User());
    return "addUser";
}

and form in jsp file

<form:form method="post" action="add" commandName="user"> 
     <form:input path="name"/>
     <form:input path="password"/>
     <form:input path="confirm-password"/>
</form:form>

This form generates error because there is no confirm-password field in User.class. I could of course add confirm-password field as @Transient to User.class, but what if I would like to add captcha field to my form. Is there a different way to add additional field to form?

Answer 1

It is not a good practice to use your models as form entities. You should have a bean or form class to get the data from the view and another for the model.

Reason is that they have different responsibilities thus needing to to be mapped to different classes. They are often very similar, but that separation promotes a cleaner coding and avoids security breaches, as a user could try to use your model variables from the view by using a request tamperer for example(like fire bug).

These small differences between them like the one you listed above justify the creation of another class.