java 结构型设计模式

以下是几种常见的Java结构型设计模式：

1. 适配器模式（Adapter Pattern）：适配器模式用于将一个类的接口转换成客户端所期望的另一个接口。它允许不兼容的类能够合作。例如，将一个已有的类的接口转换成另一个接口，以满足客户端的需求。

public interface MediaPlayer {
    public void play(String audioType, String fileName);
}

public interface AdvancedMediaPlayer {
    public void playVlc(String fileName);
    public void playMp4(String fileName);
}

public class VlcPlayer implements AdvancedMediaPlayer {
    public void playVlc(String fileName) {
        System.out.println("Playing vlc file. Name: " + fileName);
    }
    public void playMp4(String fileName) {
        // do nothing
    }
}

public class Mp4Player implements AdvancedMediaPlayer {
    public void playVlc(String fileName) {
        // do nothing
    }
    public void playMp4(String fileName) {
        System.out.println("Playing mp4 file. Name: " + fileName);
    }
}

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();
        }
    }

    public void play(String audioType, String fileName) {
        if (audioType.equalsIgnoreCase("vlc")) {
            advancedMusicPlayer.playVlc(fileName);
        } else if (audioType.equalsIgnoreCase("mp4")) {
            advancedMusicPlayer.playMp4(fileName);
        }
    }
}

public class AudioPlayer implements MediaPlayer {
    MediaAdapter mediaAdapter;

    public void play(String audioType, String fileName) {
        if (audioType.equalsIgnoreCase("mp3")) {
            System.out.println("Playing mp3 file. Name: " + fileName);
        } 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");
        }
    }
}

public class Main {
    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");
    }
}