二种饿汉单利比较

区别:第二种单利应为采用了静态内部类,只有调用改内部类时才会去new,节省了资源

package practice;public class Singletone {/*private static Singletone instance=new Singletone();private Singletone(){}private static Singletone getInstance(){return instance;}*/private Singletone(){}private static class SingletoneHolder{private final static Singletone instance=new Singletone();}private static Singletone getInstance(){return SingletoneHolder.instance;}}

PS:短短几行代码有蛮多知识点的有待梳理.