Singleton三种实现方法(effective java笔记)
public class Main {/** * @param args */public static void main(String[] args) { SEnum(); SPubF(); SStF();}public static void SEnum(){SingletonEnum.INSTANCE.doWork();}public static void SPubF(){SingletonPubField.INSTANCE.doWork();}public static void SStF(){SingletonStFactory.getInstance().doWork();}}