How can I store old value before update?

[cardel.ka.jelinek.seznam.cz]

I have some functionality that allows me to activate / deactivate user.

I have User class

public class User implements Serializable {
 private Boolean activated;

 public Boolean getActivated() {
        return activated;
    }

 public void setActivated(Boolean activated) {
        this.activated = activated;
    }
}

and home object for user (UserHome class)

I would like to know, how can I store old (active/inactive) state of user, before somenone set it to active or inactive.

For example:
I am updating active user and setting it to inactive state. So I call UserHome.update() method to update this user and in this method I can read only new value of user state. I don´t know if user was before in active or in inactive state. I need to react only on changes of user state
inactive to active and
active to inactive.

So I need to know in which state user was before update.

I tried to set some help variable in UserHome class by calling help method before rendering view. This variable was setted right, but it was delete after I call update method.

I think there exist some simple solution