设计模式——"simple Factory"

1 public interface Ball{
2     public void sayName();
3 }

1 public class Football implements Ball{
2     public void sayName() {
3         System.out.println("i am a football");
4     }
5 }

1 public class Basketball implements Ball{
2     public void sayName() {
3         System.out.println("i am a basketball ");
4     }
5 }

 1 public class BallFactory{
 2     public static Ball getBall(String ballname){
 3         Ball b = null ;
 4         if("football".equals("ballname")){
 5              b=new Football();
 6         }
 7         if("basketball".equals("ballname")){
 8              b=new Basketball();
 9         }
10         return b;
11     }
12     public static void main(String[] a){
13         Ball b = BallFactory.getBall("football");
14         b.sayName();
15     }
16 }