@ManyToMany并更新实体

Question

I have User class, which has some additional attributes:

@Entity
@Table(name="\"user\"")
public class User implements UserDetails {
    private String username;
    private String password;
    @ManyToMany(fetch = FetchType.EAGER)
    private Collection<House> houses;
}

Now, if I invoke some method that changes one of the houses (for example changes its name property), I still get the old value of the house if I call:

User user = (User) SecurityContextHolder.getContext().getAuthentication().getPrincipal();
user.getHouses(); <- value of name property in house is not updated

How can I make sure that it is always updated?

Answer 1

I would suggest you to change @ManyToMany(fetch = FetchType.EAGER) to @ManyToMany(fetch = FetchType.LAZY) . Because EAGER fetch immediately the object the first time you call it and with LAZY you have the id and you will fetch by demand, that means, with lazy you will get from the database the last state of your object.

Answer 2

You are missing a few details, based on your given information:

The Cascade is missing, there are all kind of cascade types, for the simplicity let's assume that you want every change made on your User entity will result affect on the related entity which is House, so you'll have to add Cascade.all

What about your @JoinTable and @JoinCoumn ? it also doesn't define in your entities relationship.