标签：style blog class code c java
那天别人问了我一个问题，关于单例模式的，由于之前了解的都是蜻蜓点水，所以重新复习了一次重新总结。
单例模式的写法总的来说有5种：懒汉，恶汉，枚举，双重校验锁，静态内部类
懒汉
1 public class Signleton{ 2 private static Signleton instance; 3 private Signleton(){} 4 public static synchronized Sginleton getInstance(){ 5 if( instance == null ){ 6 instance = new Signleton(); 7 } 8 return instance; 9 } 10 }
恶汉:
1 public class Singleton { 2 private Singleton instance = null; 3 static { 4 instance = new Singleton(); 5 } 6 private Singleton (){} 7 public static Singleton getInstance() { 8 return this.instance; 9 } 10 }
双重校验锁：
1 public class Singleton { 2 private volatile static Singleton singleton; 3 private Singleton (){} 4 public static Singleton getSingleton() { 5 if (singleton == null) { 6 synchronized (Singleton.class) { 7 if (singleton == null) { 8 singleton = new Singleton(); 9 } 10 } 11 } 12 return singleton; 13 } 14 }
枚举：
1 public enum Singleton { 2 INSTANCE; 3 public void whateverMethod() {} 4 }
静态内部类：
1 public class Singleton { 2 private static class SingletonHolder { 3 private static final Singleton INSTANCE = new Singleton(); 4 } 5 private Singleton (){} 6 public static final Singleton getInstance() { 7 return SingletonHolder.INSTANCE; 8 } 9 }
有兴趣的可以看这篇文章: http://stackoverflow.com/questions/70689/what-is-an-efficient-way-to-implement-a-singleton-pattern-in-java
the
best way to do it is to use：
Since java5 ：
enum:
Pre java5 ：other
设计模式——“signleton”,布布扣,bubuko.com
标签：style blog class code c java
原文地址：http://www.cnblogs.com/m-xy/p/3725055.html
