Address.java

package com;

/**
 * Created by adelin.ghanayem@cayetanogaming.com on 2/16/16.
 */
public class Address {

    private  int number;
    private  String address;

    public Address(int number, String address) {
        this.number = number;
        this.address = address;
    }

    public int getNumber() {
        return number;
    }

    public String getAddress() {
        return address;
    }

    public void setNumber(int number) {
        this.number = number;
    }

    public void setAddress(String address) {
        this.address = address;
    }
}

Main.java

package com; 

public class Main {
  
  public static void main(String[] args){
    
    //This sholud be immutable but it is not the cas ! 
    User user = new User("Adelin",true,"123",new Address(1,"some address"));// this btw is ugly constructor it can get even uglier use builder patter to make kinda acceptable !! 
    
    user.getAddress().setNumber(2); // Address is change so as User !! 
    
  }
  
  
}

User.java

package com;

/**
 * Created by adelin.ghanayem@cayetanogaming.com on 2/16/16.
 */
public final class User {
    
    
    private final String name;
    private final boolean isActive;
    private final String userId;
    private final Address address;
    
    // can be constructed using this constructor ONLY ! 
    public User(String name, boolean isActive, String userId, Address address) {
        this.name = name;
        this.isActive = isActive;
        this.userId = userId;
        this.address = address;
    }

    public String getName() {
        return name;
    }

    public boolean isActive() {
        return isActive;
    }

    public String getUserId() {
        return userId;
    }
    
    public Address getAddress(){
        return address;
    }
}