24种设计模式之单例

package com.webserver.test;

public class Singleton {
    private static Singleton singleton;
    static {
        singleton = new Singleton();
    }
    private Singleton(){
    }

    public static Singleton getSingleton(){
        return singleton;
    }

}

测试类代码

package com.webserver.test;

public class testSingleton {
    public static void main(String[] args) {
        Singleton singleton = Singleton.getSingleton();
        System.out.println(singleton);

        Singleton singleton1 = Singleton.getSingleton();
        System.out.println(singleton1);
    }
}

可以看到指向同一个地址且不能new对象