默认的MediaPlayer接口只能播放mp3格式的音乐，然而我们现在想播放vlc和mp4格式的音乐，

怎么做呢？

这里我们引入AdvancedMediaPlayer接口，AdvancedMediaPlayer接口可以播放vlc和mp4格式的音乐。

怎么将AdvancedMediaPlayer接口“适配”到MediaPlayer接口中呢？

这里引入MediaAdapter类，这个类用来适配vlc和mp4格式的音乐

最后用AudioPlayer类实现MediaPlayer接口,适配的工作交给MediaAdapter类

 类结构图如下：

 

VlcPlayer.java

package com.advance.adapter;/** * @Auther: 谷天乐 * @Date: 2018/9/20 22:58 * @Description: */public class VlcPlayer implements AdvancedMediaPlayer{    @Override    public void playVlc(String fileName) {        System.out.println("Playing vlc file. Name: "+ fileName);    }    @Override    public void playMp4(String fileName) {        //什么也不做    }}

 

Mp4Player.java

package com.advance.adapter;/** * @Auther: 谷天乐 * @Date: 2018/9/20 22:58 * @Description: */public class Mp4Player implements AdvancedMediaPlayer{    @Override    public void playVlc(String fileName) {        //什么也不做    }    @Override    public void playMp4(String fileName) {        System.out.println("Playing mp4 file. Name: "+ fileName);    }}

 

MediaPlayer.java

package com.advance.adapter;/** * @Auther: 谷天乐 * @Date: 2018/9/20 22:57 * @Description: */public interface MediaPlayer {    public void play(String audioType, String fileName);}

 

MediaAdapter.java

package com.advance.adapter;/** * @Auther: 谷天乐 * @Date: 2018/9/20 22:58 * @Description: */public class MediaAdapter implements MediaPlayer {    AdvancedMediaPlayer advancedMusicPlayer;    public MediaAdapter(String audioType){        if(audioType.equalsIgnoreCase("vlc") ){            advancedMusicPlayer = new VlcPlayer();        } else if (audioType.equalsIgnoreCase("mp4")){            advancedMusicPlayer = new Mp4Player();        }    }    @Override    public void play(String audioType, String fileName) {        if(audioType.equalsIgnoreCase("vlc")){            advancedMusicPlayer.playVlc(fileName);        }else if(audioType.equalsIgnoreCase("mp4")){            advancedMusicPlayer.playMp4(fileName);        }    }}

 

AudioPlayer.java

package com.advance.adapter;/** * @Auther: 谷天乐 * @Date: 2018/9/20 22:59 * @Description: */public class AudioPlayer implements MediaPlayer {    MediaAdapter mediaAdapter;    @Override    public void play(String audioType, String fileName) {        //播放 mp3 音乐文件的内置支持        if(audioType.equalsIgnoreCase("mp3")){            System.out.println("Playing mp3 file. Name: "+ fileName);        }        //mediaAdapter 提供了播放其他文件格式的支持        else if(audioType.equalsIgnoreCase("vlc")                || audioType.equalsIgnoreCase("mp4")){            mediaAdapter = new MediaAdapter(audioType);            mediaAdapter.play(audioType, fileName);        }else{            System.out.println("Invalid media. "+                    audioType + " format not supported");        }    }}

 

AdvancedMediaPlayer.java

package com.advance.adapter;/** * @Auther: 谷天乐 * @Date: 2018/9/20 22:57 * @Description: */public interface AdvancedMediaPlayer {    public void playVlc(String fileName);    public void playMp4(String fileName);}

 

AdapterPatternDemo.java

package com.advance.adapter;/** * @Auther: 谷天乐 * @Date: 2018/9/20 22:59 * @Description: */public class AdapterPatternDemo {    public static void main(String[] args) {        AudioPlayer audioPlayer = new AudioPlayer();        audioPlayer.play("mp3", "beyond the horizon.mp3");        audioPlayer.play("mp4", "alone.mp4");        audioPlayer.play("vlc", "far far away.vlc");        audioPlayer.play("avi", "mind me.avi");    }}

 

运行结果

Playing mp3 file. Name: beyond the horizon.mp3Playing mp4 file. Name: alone.mp4Playing vlc file. Name: far far away.vlcInvalid media. avi format not supported