单例模式，模式,class Single

单例模式，模式,class Single

class Single{    private static Single instance=null;    static{//饿汉模式        instance=new Single();    }    private Single(){}//将构造方法私有，不允许创建对象    public static Single getInstance(){        if(instance==null){//懒汉模式            instance=new Single();        }        return instance;    }}public class SingleTest {//测试类    public static void main(String[] args){        Single s1=Single.getInstance();        Single s2=Single.getInstance();        System.out.println(s1==s2);        System.out.println(s1.toString());        System.out.println(s2.toString());    }}//该片段来自于http://byrx.net