Singleton instantiation

Question

Below show is the creation on the singleton object.

public class Map_en_US extends mapTree {

    private static Map_en_US m_instance;

    private Map_en_US         


        

Answer 1

    // Best way to implement the singleton class in java
    package com.vsspl.test1;

    class STest {

        private static STest ob= null;
        private  STest(){
            System.out.println("private constructor");
        }

        public static STest  create(){

            if(ob==null)
                ob = new STest();
            return ob;
        }

        public  Object  clone(){
            STest   obb = create();
            return obb;
        }
    }

    public class SingletonTest {
        public static void main(String[] args)  {
            STest  ob1 = STest.create();
            STest  ob2 = STest.create();
            STest  ob3 = STest.create();

            System.out.println("obj1  " +  ob1.hashCode());
            System.out.println("obj2  " +  ob2.hashCode());
            System.out.println("obj3  " +  ob3.hashCode());


            STest  ob4 = (STest) ob3.clone();
            STest  ob5 = (STest) ob2.clone();
            System.out.println("obj4  " +  ob4.hashCode());
            System.out.println("obj5  " +  ob5.hashCode());

        }
    }

-------------------------------- OUT PUT -------------------------------------
private constructor
obj1  1169863946
obj2  1169863946
obj3  1169863946
obj4  1169863946
obj5  1169863946