why adapter should be type of target? Is below code is in adapter pattern?

This is interface player :

   public interface MediaPlayer {
        void play(String mediaType, String item);
    }

This is basic player :

    public class AudioPlayer implements MediaPlayer {

        private MediaAdapter mediaAdapter ;

        @Override
        public void play(String mediaType, String item) {
            if (mediaType.equals("mp3")) {
                System.out.println("Playing mp3" + item);
            } else if (mediaType.equals("vlc") || mediaType.equals("mp4")) {
                mediaAdapter = new MediaAdapter(mediaType);
                mediaAdapter.pluginPlayer(item);
            } else {
                System.out.println("invalid media type");
            } 

        }

    }

This is my adpater. It is not of type MediaPlayer.

    public class MediaAdapter {

        private AdvanceMediaPlayer advanceMediaPlayer;

        public MediaAdapter(String mediaType) {
            if (mediaType.equals("vlc")) {
                advanceMediaPlayer = new VLCPlayer();
            } else if (mediaType.equals("mp4")) {
                advanceMediaPlayer = new MP4Player();
            }
        }

        public void pluginPlayer(String item) {
            advanceMediaPlayer.play(item);
        }

    }

This is advance media player.

    public interface AdvanceMediaPlayer {

        void play(String item);

    }

This is a type of advance media player.

    public class VLCPlayer implements AdvanceMediaPlayer {

        @Override
        public void play(String item) {
            System.out.println("Playing vlc : " + item);
        }

    }

This is another advance media player.

    public class MP4Player implements AdvanceMediaPlayer {

        @Override
        public void play(String item) {
            System.out.println("Playing MP4 : " + item);
        }

    }

This is my test class.

    public class Test {

        public static void main(String[] args) {
            AudioPlayer audioPlayer = new AudioPlayer();
            audioPlayer.play("mp3", "mp3 song");
            audioPlayer.play("vlc", "vlc song");
            audioPlayer.play("mp4", "mp4 song");
            audioPlayer.play("avi", "avi songs");
        }

    }