java 几种常见的单例模式

来源：互联网发布：淘宝扣24分怎么办编辑：程序博客网时间：2024/05/18 00:28

前言：直接介绍几种线程安全的且我觉得还比较不错的方式：
1.

public class Singleton  {      private static Singleton instance = new Singleton();      public static Singleton getInstance()      {          return instance ;      }  }

2、懒汉

public class Singleton02  {      private static Singleton02 instance;      public static Singleton02 getInstance()      {          if (instance == null)          {              synchronized (Singleton02.class)              {                  if (instance == null)                  {                      instance = new Singleton02();                  }              }          }          return instance;      }  }

3、使用一个持有类，主要是为了不在初始化的时候加载

public class Singleton04  {      private static final class InstanceHolder      {          private static Singleton04 INSTANCE = new Singleton04();      }      public static Singleton04 getInstance()      {          return InstanceHolder.INSTANCE;      }  }

0 0