Java pass by value

package com.alogrithm.test2;public class Refs  {   public static void main(String[] args)  {      MyPoint p1 = new MyPoint(10, 20);      MyPoint p2 = new MyPoint(30, 40);      System.out.println("Before swap() p1 is " + p1 + ", and p2 is " + p2);      swap(p1, p2);      System.out.println("After swap() p1 is " + p1 + ", and p2 is " + p2);      System.out.println("----------------------------------------------");      System.out.println("Before change_1(), p1 is " + p1);      change_1(p1);      System.out.println("After change_1(), p1 is " + p1);      System.out.println("----------------------------------------------");      System.out.println("Before change_2(), p1 is " + p1);      change_2(p1);      System.out.println("After change_2(), p1 is " + p1);      System.out.println("----------------------------------------------");       return;   }   public static void swap(MyPoint arg1, MyPoint arg2)  {      MyPoint temp;      temp = arg1;      arg1 = arg2;      arg2 = temp;      System.out.println("In swap() p1 is " + arg1 + ", and p2 is " + arg2);   }   public static void change_1(MyPoint arg1)  {      arg1 = new MyPoint(100, 100);      System.out.println("In change_1() p1 is " + arg1);   }   public static void change_2(MyPoint arg1)  {      arg1.x = 100;      arg1.y = 101;      System.out.println("In change_1() p1 is " + arg1);   }}class MyPoint  {      public Integer x, y;      public MyPoint(Integer arg_x, Integer arg_y)  {         x = arg_x;         y = arg_y;      }      public String toString()  {         return "MyPoint[x=" + x + ",y=" + y + "]";      }}