package test;

//单例设计模式
public class Singleton {

    private Singleton() {}

    private static Singleton st = new Singleton();

    static Singleton getInstance(){
        return st;
    }
}

class SingletonTest {
    public static void main(String[] args) {
//        Singleton s1 = new Singleton();
//        Singleton s2 = new Singleton();
//        System.out.println(s1 == s2); //false

        Singleton s1 = Singleton.getInstance();
        Singleton s2 = Singleton.getInstance();
        System.out.println(s1 == s2); //true
    }
}