单例模式

 1 package jquery;
 2 
 3 
 4 public class Singleton {
 5 
 6     //属性私有,因为提供获取对象的方法所以static声明
 7     private static Singleton singleton;
 8     
 9     //构造器私有，别人没法new对象
10     private Singleton(){
11         //在构造器就吃，属于饿汉模式
12         singleton=new Singleton();
13     }
14     
15     public static Singleton getSingleton(){
16         return singleton;
17     }
18 }

 1 package jquery;
 2 
 3 public class Singletonlan {
 4 
 5     private static Singletonlan singletonlan;
 6     
 7     private Singletonlan(){
 8         
 9     }
10     
11     public static Singletonlan getSingletonlan(){
12         if(singletonlan==null){
13             return new Singletonlan();
14         }
15         return null;
16     }
17 }