策略模式

1 public interface FlyBehavior {
2     public void fly();
3 }

1 public interface QuackBehavior {
2     
3     public void quack();
4     
5 }

1 public class FlyWithNoWings implements FlyBehavior {
2 
3     @Override
4     public void fly() {
5         System.out.println("不会飞的鸭子");
6     }
7 
8 }

1 public class FlyWithWings implements FlyBehavior {
2 
3     @Override
4     public void fly() {
5         System.out.println("会飞的鸭子");
6     }
7 
8 }

1 public class MuteQuack implements QuackBehavior {
2 
3     @Override
4     public void quack() {
5         System.out.println("发出的声音是-->>" + "MuteQuack");
6     }
7 
8 }

1 public class Quack implements QuackBehavior {
2 
3     @Override
4     public void quack() {
5         System.out.println("发出的声音是-->>" + "Quack");
6     }
7 
8 }

1 public class Squeak implements QuackBehavior {
2 
3     @Override
4     public void quack() {
5         System.out.println("发出的声音是-->>" + "Sequck");
6     }
7 
8 }

 1 /**
 2  * 鸭子具有什么行为就组合什么相关实现类
 3  * 
 4  * @author liang
 5  * 
 6  */
 7 public abstract class Duck {
 8     public FlyBehavior mFlyBehavior;
 9     public QuackBehavior mQuackBehavior;
10     
11     public abstract void display();// 必须实现的一个方法
12     
13     // 委托给行为类
14     public void performFly(){
15         mFlyBehavior.fly();
16     }
17     
18     public void performQuack(){
19         
20         mQuackBehavior.quack();
21     }
22 
23 }

 1 public class MallaredDuck extends Duck {
 2 
 3     public MallaredDuck() {
 4         mFlyBehavior = new FlyWithWings();
 5         mQuackBehavior = new Squeak();
 6     }
 7 
 8     @Override
 9     public void display() {
10         System.out.println("展示一只鸭子");
11     }
12 
13 }

 1 public class MainActivity extends Activity {
 2 
 3     private Button btn;
 4 
 5     @Override
 6     protected void onCreate(Bundle savedInstanceState) {
 7         super.onCreate(savedInstanceState);
 8         setContentView(R.layout.activity_main);
 9         btn = (Button) findViewById(R.id.btn);
10         btn.setOnClickListener(new OnClickListener() {
11 
12             @Override
13             public void onClick(View v) {
14                 Duck mallard = new MallaredDuck();
15                 mallard.performFly();
16                 mallard.performQuack();
17             }
18         });
19     }
20 
21 }