Java Object Reference and assignment

Case:

Package com.util;

Import java.util.ArrayList;
Import java.util.List;

public class Copyobjectutil {
private static list<string> List;
private static User usertemp;
static{
List=new arraylist<string> ();
List.add ("AA");
List.add ("BB");

Usertemp=new User ();
Usertemp.setname ("CA");
Usertemp.setremark ("original value");
Usertemp.setage (20);
}

public static void Main (string[] args) {
List<user> userlist=new arraylist<user> ();
for (int i=0;i<list.size (); i++) {
User User =new User ();
User=usertemp;
User.setname (List.get (i));
User.setage (User.getage () +i);
Userlist.add (user);
}
int i=0;
for (User o:userlist) {
System.out.println ("= = =" +i+++ "=======");
System.out.println (O.getname ());
System.out.println (O.getremark ());
System.out.println (O.getage ());
}

}

}
Class user{
private String name;
Private String remark;
private int age;
Public String GetName () {
return name;
}
public void SetName (String name) {
THIS.name = name;
}
Public String Getremark () {
return remark;
}
public void Setremark (String remark) {
This.remark = remark;
}
public int getage () {
return age;
}
public void Setage (int.) {
This.age = age;
}

}
Output Result:

====0=======
Bb
Original value
21st
====1=======
Bb
Original value
21st

Problem: The value of the previous object in list is overwritten by the latter object from the result table item.

User User =new User ();
User=usertemp;

Cause: The address that points to the same object,list<user> references the same object, which is usertemp=new user (), the static block, and the for loop modifies it, actually modifies the same object, The previous value of the solid will appear after the phenomenon of the value;

Solution:

Plan

public static void Main (string[] args) throws exception{
List<user> userlist=new arraylist<user> ();
for (int i=0;i<list.size (); i++) {
User User =new User ();
User= (User) Beanutils.clonebean (usertemp);
User.setname (List.get (i));
User.setage (User.getage () +i);
Userlist.add (user);
}
int i=0;
for (User o:userlist) {
System.out.println ("= = =" +i+++ "=======");
System.out.println (O.getname ());
System.out.println (O.getremark ());
System.out.println (O.getage ());
}

}

Output:

====0=======
Aa
Original value
20
====1=======
Bb
Original value
21st

Solution 2--

public static void Main (string[] args) throws exception{
List<user> userlist=new arraylist<user> ();
for (int i=0;i<list.size (); i++) {
User User =new User ();
Beanutils.copyproperties (usertemp, user);
User.setname (List.get (i));
User.setage (User.getage () +i);
Userlist.add (user);
}
int i=0;
for (User o:userlist) {
System.out.println ("= = =" +i+++ "=======");
System.out.println (O.getname ());
System.out.println (O.getremark ());
System.out.println (O.getage ());
}

}

Output:

Aa
Original value
20
====1=======
Bb
Original value
21st

Java Object Reference and assignment