单例模式

 1 class People{
 2     /**
 3      * 恶汉单例设计模式
 4      */
 5     private static People p=new People(); 
 6     private People(){
 7     }
 8     public static People getPeople(){
 9         return p;
10     }
11 }
12 class Person{
13     /**
14      * 懒汉单例设计模式
15      */
16     private static Person p1;
17     private Person(){
18     }
19     public static Person getPerson(){
20         if (p1==null) {
21             p1=new Person();
22             return p1;
23         }
24         return p1;
25     }
26 }