Output registered users as Json in spring mvc - json

Question

I have a simple form for registration with generated id and then title, username and password. Once user is registered I want to go to Json page and be able to pull that data in there, is that even possible? if so how is it done? This is what I have at the moment but that doesn't work.
Model:
public class User {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Long id;
private String title;
#NotNull
#Size(min=2, max=30)
private String username;
#NotNull
#Size(min=6)
private String password;
public String getTitle() { return title; }
public String getUsername() { return username; }
public String getPassword() { return password; }
public Long getId() { return id; }
public void setId(Long id) {
this.id = id;
}
public void setUsername(String username) { this.username = username; }
public void setPassword(String password) { this.password = password; }
public void setTitle(String title) { this.title = title; }
public List<Note> getNotes() {
return notes;
}
#OneToMany
private List<Note> notes = new ArrayList<Note>();
}
Controller:
#RequestMapping(value = "/json", method = RequestMethod.GET)
#ResponseBody
public User json(){
User user = new User();
user.setId(id);
user.setTitle(title);
user.setUsername(username);
user.setPassword(password);
return user;
}
}