设计模式之单例

设计模式之单例

参考:http://blog.csdn.net/zhengzhb/article/details/7331369

除了饿汉式单例,懒汉式单例

还有一种用内部类来维护单例的方式:

public class StaticSingleton {private StaticSingleton(){System.out.println("StaticSingleton is create");}private static class SingletonHolder {private static StaticSingleton instance = new StaticSingleton();}public static StaticSingleton getInstance() {return SingletonHolder.instance;}public static void createString(){System.out.println("createString in Singleton");}}

外部类加载时其内部类并不会初始化，只有在调用getInstance时才会初始化内部类，从而初始化单例，结果了懒汉式的特点同时又不需要synchronized互斥，损耗折衷