01-单例模式 [枚举]

package com.design.patterns;/*** * @author Fighting* 使用枚举*/
public class EnumSingleton {public static void main(String[] args) {SingletonEnum instance = SingletonEnum.INSTANCE;SingletonEnum instance2 = SingletonEnum.INSTANCE;System.out.println(instance == instance2);System.out.println(instance.hashCode());System.out.println(instance2.hashCode());}}enum SingletonEnum{INSTANCE
}