java设计模式之命令模式

/**
 * 具体工作的类（录音机）
 */
public class AudioPlayer {

    public void play() {
        System.out.println("播放...");
    }

    public void rewind() {
        System.out.println("倒带...");
    }

    public void stop() {
        System.out.println("停止播放...");
    }
}

/**
 * 执行录音机的命令
 */
public interface Command {

    public void execute();
}

/**
 * 播放命令
 */
public class PlayCommand implements Command {
    private AudioPlayer audioPlayer;

    public PlayCommand(AudioPlayer audioPlayer) {
        this.audioPlayer = audioPlayer;
    }

    @Override
    public void execute() {
        audioPlayer.play();
    }
}

/**
 * 倒带命令
 */
public class RewindCommand implements Command {

    private AudioPlayer audioPlayer;

    public RewindCommand(AudioPlayer audioPlayer) {
        this.audioPlayer = audioPlayer;
    }

    @Override
    public void execute() {
        audioPlayer.rewind();
    }
}

/**
 * 停止命令
 */
public class StopCommand implements Command {
    private AudioPlayer audioPlayer;

    public StopCommand(AudioPlayer audioPlayer) {
        this.audioPlayer = audioPlayer;
    }

    @Override
    public void execute() {
        audioPlayer.stop();
    }
}

**
 * 按键类
 */
public class Keypad {

    private Command playCommand;
    private Command rewindCommand;
    private Command stopCommand;

    public void setPlayCommand(Command playCommand) {
        this.playCommand = playCommand;
    }

    public void setRewindCommand(Command rewindCommand) {
        this.rewindCommand = rewindCommand;
    }

    public void setStopCommand(Command stopCommand) {
        this.stopCommand = stopCommand;
    }

    /**
     * 执行播放
     */
    public void pay() {
        playCommand.execute();
    }

    /**
     * 执行倒带
     */
    public void rewind() {
        rewindCommand.execute();
    }

    /**
     * 执行停止
     */
    public void stop() {
        stopCommand.execute();
    }
}

/**
 * 操作按钮-》发送命令给录音机执行具体操作
 */
public class CommandMain {

    public static void main(String[] args) {
        //new 一个录音机
        AudioPlayer audioPlayer = new AudioPlayer();
        //创建播放命令对象
        Command playCommand = new PlayCommand(audioPlayer);
        //创建倒带命令对象
        Command rewindCommand = new RewindCommand(audioPlayer);
        //创建停止命令对象
        Command stopCommand = new StopCommand(audioPlayer);
        //创建按键对象
        Keypad keypad = new Keypad();
        //将播放命令绑定在按键上
        keypad.setPlayCommand(playCommand);
        //将倒带命令绑定在按键上
        keypad.setRewindCommand(rewindCommand);
        //将停止命令绑定在按键上
        keypad.setStopCommand(stopCommand);
        //播放
        keypad.pay();
        //倒带
        keypad.rewind();
        //停止
        keypad.stop();

        keypad.pay();
        keypad.stop();

    }
}