单例设计模式(饿汗式,懒汉式)

<div>饿汉式：</div>

class  SingleApp
{
	public static void main(String[] args) 
	{
		//Single sgl = new Single();
		Single sg1 = Single.made();
		Single sg2 = Single.made();
		sg1.speak();
		sg2.speak();
System.out.println(sg1);
		System.out.println(sg1);
	} 
}
//饿汉式
class Single
{
	static Single s = new Single();
	private Single()
	{
	}

	public void speak(){
		System.out.println("haoren");
	}

	public static Single made(){
		return s;
	}

}

懒汉式：

//懒汉式
class Single
{
	static Single s = null;
	private Single()
	{
	}

	public void speak(){
		System.out.println("haoren");
	}

	public static Single made(){
		if(s==null)
		s = new Single();
		}
		return s;
	}

}