VIP31/spring-demo/src/main/java/com/sf/javase/singleton/Singleton4.java

package com.sf.javase.singleton;

/**
 * 枚举
 * 是实现单例的最好方法
 */
public enum Singleton4 {
    // final class Singleton4
    INSTANCE;
    //static final Singleton4 INSTANCE = new Singleton4();
}