《Head First 设计模式》之命令模式——遥控器

 1 interface Command {
 2   public void execute();
 3 }
 4 
 5 class Light {
 6   public void on() {
 7     System.out.println("light on");
 8   }
 9 
10   public void off() {
11     System.out.println("light off");
12   }
13 }
14 
15 class LintOnCommand implements Command {
16   Light light;
17 
18   public LintOnCommand(Light light) {
19     this.light = light;
20   }
21 
22   @Override
23   public void execute() {
24     light.on();
25   }
26 
27 }
28 
29 class SimpleRemoteControl {
30   Command command;
31 
32   public SimpleRemoteControl() {}
33 
34   public void setCommand(Command command) {
35     this.command = command;
36   }
37 
38   public void buttonWasPressed() {
39     command.execute();
40   }
41 }
42 
43 public class Test {
44   public static void main(String[] args) {
45     SimpleRemoteControl control = new SimpleRemoteControl();
46     Light light = new Light();
47     LintOnCommand onCommand = new LintOnCommand(light);
48 
49     control.setCommand(onCommand);
50     control.buttonWasPressed();
51   }
52 }