Java_单例模式

1. 懒汉式单例模式：在真正用到的时候才去创建这个单例对象

class Single {private static Single instance = null;private Single(){//将构造方法私有化，防止外部创建类实例}synchronized public static Single getInstance(){if (instance == null)instance = new Single();return instance;}}

2. 饿汉式单例模式：不管你用得上用不上，一开始就创建这个单利对象

class Single {private static Single instance = new Single();private Single(){//将构造方法私有化，防止外部创建类实例}synchronized public static Single getInstance(){return instance;}}