分享一个例子：笔记本通过读卡去读取TF卡；

一、先模拟计算机读取SD卡：

1、先创建一个SD卡的接口：

public interface SDCard {
    //读取SD卡方法
    String readSD();
    //写入SD卡功能
    int writeSD(String msg);
}

2、创建SD卡接口的实现类，模拟SD卡的功能：

public class SDCardImpl implements SDCard {
    @Override    
    public String readSD() {
        String msg = "sdcard read a msg :hello word SD";
        return msg;  
    }
    @Override  
    public int writeSD(String msg) {      
        System.out.println("sd card write msg : " + msg);    
        return 1;   
    }
}

3、创建计算机接口，计算机提供读取SD卡方法：

public interface Computer {    
    String readSD(SDCard sdCard);
}

4、创建一个计算机实例，实现计算机接口，并实现其读取SD卡方法：

public class ThinkpadComputer implements Computer {
    @Override    
    public String readSD(SDCard sdCard) {        
        if(sdCard == null)throw new NullPointerException("sd card null");        
        return sdCard.readSD();    
    }
}

5、这时候就可以模拟计算机读取SD卡功能：

public class ComputerReadDemo {    
    public static void main(String[] args) {        
        Computer computer = new ThinkpadComputer();        
        SDCard sdCard = new SDCardImpl();       
        System.out.println(computer.readSD(sdCard));    
    }
}

二、接下来在不改变计算机读取SD卡接口的情况下，通过适配器模式读取TF卡：

1、创建TF卡接口：

public interface TFCard {    
    String readTF();    
    int writeTF(String msg);
}

2、创建TF卡实例：

public class TFCardImpl implements TFCard {    
    @Override    
    public String readTF() {        
        String msg ="tf card reade msg : hello word tf card";        
        return msg;    
    }    
    @Override    
    public int writeTF(String msg) {        
        System.out.println("tf card write a msg : " + msg);        
        return 1;    
    }
}

3、创建SD适配TF （也可以说是SD兼容TF，相当于读卡器）：

实现SDCard接口，并将要适配的对象作为适配器的属性引入。

public class SDAdapterTF implements SDCard {    
    private TFCard tfCard;    
    public SDAdapterTF(TFCard tfCard) {        
        this.tfCard = tfCard;    
    }    
    @Override    
    public String readSD() {        
        System.out.println("adapter read tf card ");        
        return tfCard.readTF();    
    }    
    @Override    
    public int writeSD(String msg) {        
        System.out.println("adapter write tf card");        
        return tfCard.writeTF(msg);    
    }
}

4、通过上面的例子测试计算机通过SD读卡器读取TF卡：

public class ComputerReadDemo {    
    public static void main(String[] args) {        
        Computer computer = new ThinkpadComputer();        
        SDCard sdCard = new SDCardImpl();        
        System.out.println(computer.readSD(sdCard));        
        System.out.println("====================================");        
        TFCard tfCard = new TFCardImpl();        
        SDCard tfCardAdapterSD = new SDAdapterTF(tfCard);        
        System.out.println(computer.readSD(tfCardAdapterSD));    
    }
}

输出：

sdcard read a msg :hello word SD
====================================
adapter read tf card 
tf card reade msg : hello word tf card

在这种模式下，计算机并不需要知道具体是什么卡，只需要负责操作接口即可，具体操作的什么类，由适配器决定。

Python 方式：

#Adapter Pattern with Python Code
from abc import abstractmethod,ABCMeta

# 为媒体播放器和更高级的媒体播放器创建接口
class MediaPlayer(metaclass=ABCMeta):
    @abstractmethod
    def play(self, strAudioType, strFilename):
        pass
class AdvancedMediaPlayer(metaclass=ABCMeta):
    @abstractmethod
    def playVlc(self,strFilename):
        pass
    @abstractmethod
    def playMp4(self,strFilename):
        pass

# 实现AdvancedMediaPlayer接口的实体类
class VlcPlayer(AdvancedMediaPlayer):
    def playVlc(self,strFilename):
        print("Playing vlc file. Name: "+strFilename)
    def playMp4(self,strFilename):
        pass
class Mp4Player(AdvancedMediaPlayer):
    def playVlc(self,strFilename):
        pass
    def playMp4(self,strFilename):
        print("Playing MP4 file. Name: " + strFilename)

# 实现MediaPlayer的MediaAdapter实体类
class MediaAdapter(MediaPlayer):
    advancedMusicPlayer = None

    def __init__(self,strAudioType):
        strAudioType = str.lower(strAudioType)
        if strAudioType == "vlc" :
            self.advancedMusicPlayer = VlcPlayer()
        elif strAudioType == "mp4" :
            self.advancedMusicPlayer = Mp4Player()
    def play(self,strAudioType,strFilename):
        if strAudioType == "vlc" :
            self.advancedMusicPlayer.playVlc(strFilename)
        elif strAudioType == "mp4" :
            self.advancedMusicPlayer.playMp4(strFilename)

# 实现MediaPlayer的AudiPlayer实体类
class AudioPlayer(MediaPlayer):
    mediaAdapter = None
    def play(self,strAudioType,strFilename):
        strAudioType = str.lower(strAudioType)
        # 播放MP3音乐文件
        if strAudioType == "mp3" :
            print("Playing mp3 file. Name: "+ strFilename)
        elif (strAudioType == "vlc") or (strAudioType == "mp4") :
            self.mediaAdapter = MediaAdapter(strAudioType)
            self.mediaAdapter.play(strAudioType,strFilename)
        else :
            print("Invalid media. "+ strAudioType + " format not supported.")

# 调用输出
if __name__ == '__main__':
    audioPlayer = 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")