package com.bjsxt.base;
class Sigleton{
private Sigleton(){};
private static Sigleton instance = new Sigleton();
public static Sigleton getInstance(){
return instance;
}
}
public class TestSigleton {
public static void main(String[] args) {
Sigleton s1 = Sigleton.getInstance();
Sigleton s2 = Sigleton.getInstance();
System.out.print(s1==s2);
}
}
========================================================================
package com.bjsxt.base;
class Sig{
private static Sig instance = null;
private Sig(){};
public static synchronized Sig getInstance(){
if (instance ==null){
instance = new Sig();
}
return instance;
}
}
public class AAA {
public static void main(String[] args) {
Sig s1 = Sig.getInstance();
Sig s2 = Sig.getInstance();
System.out.print(s1==s2);
}
}