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;
	}
}