简单工程模式

 1 public class FactoryDemo{
 2     public static void main(String []args){
 3         IFruit fruit = Factory.getFruit("橘子");
 4         if(fruit!=null){
 5             System.out.println(fruit.get());
 6         }
 7         else{
 8             System.out.println("你要的东西不存在");
 9         }
10     }
11 }
12 
13 interface IFruit{
14     public String get();
15 }
16 
17 class Factory{
18     public static IFruit getFruit(String name){
19         if(name.equals("苹果"))
20         {
21              return new Apple();
22         }
23         else if(name.equals("橘子"))
24         {
25              return new Orange();
26         }
27         else
28         {
29             return null;
30         }
31     }
32 }
33 
34 class Apple implements IFruit{
35     public String get(){
36         return "采摘苹果";
37     }
38 }
39 
40 class Orange implements IFruit{
41     public String get(){
42         return "采摘橘子";
43     }
44 }