Java studies a simple algorithm and encounters this output. Well, I didn't really pay attention to it before ......

Java studies a simple algorithm and encounters this output. Well, I didn't really pay attention to it before ......

Java studies a simple algorithm and encounters this output. Well, I didn't really pay attention to it before ......

What is this running principle ?????

 

package org.rui.util;import java.util.HashMap;import java.util.Map;public class A{public static void main(String[] args){Map
 
   m = new HashMap
  
   ();Map m2 = m;m2.put("a", "ava");System.out.println(m);//////////////B b = new B();B b2 = b;b2.setId(100);b2.setName("abc");b.setId(50);B b3=b2;b3.setName("B3");System.out.println(b);System.out.println(b2);System.out.println(b3);}}/*** * output:{a=ava}B [id=50, name=B3]B [id=50, name=B3]B [id=50, name=B3] */
  
 

package org.rui.util;import java.util.HashMap;import java.util.Map;public class B{private Integer id;private String name;public Integer getId(){return id;}public void setId(Integer id){this.id = id;}public String getName(){return name;}public void setName(String name){this.name = name;}@Overridepublic String toString(){return "B [id=" + id + ", name=" + name + "]";}public static void main(String[] args){Map m=new HashMap();Map m2=m;m2.put("m2","m2v");    Map
 
   m3=null;    System.out.println("---------------------------------");m3=new HashMap
  
   ();m3.put("m3_1", "m3v_1");m2.put("m2add3_1", m3);m2=m3;System.out.println("m:"+m);System.out.println("m2:"+m2);System.out.println("m3:"+m3);System.out.println("---------------------------------");m3=new HashMap
   
    ();m3.put("m3_2", "m3v_2");m2.put("m2add3_2", m3);System.out.println("m2xx:"+m2);m2=m3;System.out.println("m:"+m);System.out.println("m2:"+m2);System.out.println("m3:"+m3);}}/***output: ---------------------------------m:{m2add3_1={m3_1=m3v_1}, m2=m2v}m2:{m3_1=m3v_1}m3:{m3_1=m3v_1}---------------------------------m2xx:{m2add3_2={m3_2=m3v_2}, m3_1=m3v_1}m:{m2add3_1={m2add3_2={m3_2=m3v_2}, m3_1=m3v_1}, m2=m2v}m2:{m3_2=m3v_2}m3:{m3_2=m3v_2} */