今天朋友找我给做道题,双例模式,我是没听说过,都说是单例模式和多例模式,
也不知道双例模式什么时候用,就简单写了一个案例,不知道对不对,个人感觉蛮对的,双例就是单例+单例,废话不说了!!!!
/**单例模式调用方法Singleton singleton = Singleton.getSingleton();singleton.getValue("我是单例模式");*/ public class Singleton { private static Singleton singleton = null; public static Singleton getSingleton(){ if(singleton==null){ return singleton = new Singleton(); }else{ return singleton; } } public String getValue(String name){ return name; }}/**双例模式,如果是三例模式就吧len参数改成3调用方法Doubleton doubleton = Doubleton.getDoubleton();doubleton.getValue("我有两个实例!");*/import java.util.ArrayList;import java.util.List;import java.util.Random;public class Doubleton { private static List<Doubleton> list = new ArrayList<Doubleton>(); private static int len = 2; static{ for(int i=0;i<len;i++){ list.add(new Doubleton()); } } public static Doubleton getDoubleton (){ Random random = new Random(); int current = random.nextInt(len); return (Doubleton)list.get(current); } public String getValue(String name){ return name; }}
希望大牛们给指点指点对不对,在此感谢!!!!
原标题:java单例模式和双例模式
关键词:JAVA