单例模式

 1 public class Singleton {
 2     
 3 private static Singleton singleton;
 4     //懒汉式单例
 5     private static Singleton singleton;
 6     private Singleton(){
 7     }
 8     
 9     public static synchronized Singleton getSingleton() {
10         if (singleton == null) {
11             singleton = new Singleton();
12         }
13         return singleton;
14     }
15 }    

1 public class Singleton {
2   private static Singleton singleton = new Singleton();
3     private Singleton(){
4     }
5     
6     public static synchronized Singleton getSingleton() {
7         return singleton;
8     }  
9 }