singleton.zip

package com.bila.singleton; /** * @Author: Magician * @Desc: * 单例模式03 - 懒汉模式 - DCL：双重校验 * 基于Singleton02，减小锁的粒度，将synchronized锁代码块 * * 注意：必须进行双重校验，不然存在线程安全问题 * * 比较完美的写法 * * @Date: 2020/06/28 * @Modify By: */ public class Singleton03 { private static Singleton03 instance ; private Singleton03() {} public static Singleton03 getInstance() { if (instance == null) { synchronized (Singleton03.class) { if (instance == null) { instance = new Singleton03(); } } } return instance; } }