1. 类适配器模式

目标角色，这里假如规定了可以播放视频的格式

public interface PlayerFormat {
    public void playerMP4();
    public void playerAVI();
    public void playerRMVB();
}

当前的播放器只能播放MP4格式的视频

public class Player {
    public void playerMP4() {
        System.out.println("播放MP4视频");
    };
}

使用适配器继承了Player，又实现了PlayerFormat的接口，现在这个视频器就能播放MP4、AVI、RMVB三种格式的视频了

public class PlayerAdapter extends Player implements PlayerFormat{

    @Override
    public void playerAVI() {
        System.out.println("播放AVI视频");
    }

    @Override
    public void playerRMVB() {
        System.out.println("播放RMVB视频");
    }

}

测试

PlayerAdapter player = new PlayerAdapter();
player.playerMP4();
player.playerAVI();
player.playerRMVB();

输出

播放MP4视频
播放AVI视频
播放RMVB视频

2. 对象适配器模式

对象适配器模式与类适配器就adapter不同，具体如下代码

public class PlayerAdapter2 implements PlayerFormat{
    private Player player;
    
    public PlayerAdapter2(Player player) {
        super();
        this.player = player;
    }

    @Override
    public void playerMP4() {
        player.playerMP4();
    }

    @Override
    public void playerAVI() {
        System.out.println("播放AVI视频");
    }

    @Override
    public void playerRMVB() {
        System.out.println("播放RMVB视频");
    }

}

测试

PlayerAdapter2 player = new PlayerAdapter2(new Player());
player.playerMP4();
player.playerAVI();
player.playerRMVB();

输出

播放MP4视频
播放AVI视频
播放RMVB视频