Android实现媒体播放_01最简单的仅记录下流程

以下记录用 Service + MediaPlayer 实现网络音频文件的播放

1. Service 的实现

public class MusicPlayerService extends Service
        implements MediaPlayer.OnPreparedListener, MediaPlayer.OnCompletionListener, MediaPlayer.OnBufferingUpdateListener,
        MediaPlayer.OnErrorListener, MediaPlayer.OnInfoListener {

    private String TAG = "Music-->log--> MusicPlayerService";
    //当前正在工作的播放器对象
    private MediaPlayer mMediaPlayer;


    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.d(TAG, "onStartCommand: intent " + intent + " flags " + flags + " startId " + startId);
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public IBinder onBind(Intent intent) {
        Log.d(TAG, "onBind: intent " + intent);

        //设置代理，所有播放相关的操作通过代理暴露给Avtivity
        MusicPlayerBinder musicPlayerBinder = new MusicPlayerBinder(MusicPlayerService.this);

        prepareMusic();
        return musicPlayerBinder;
    }

    /**
     * 准备MediaPlayer环境
     */
    private void prepareMusic() {
        try {
            mMediaPlayer = new MediaPlayer();
            mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC); //设置音频流的类型。
            mMediaPlayer.setOnPreparedListener(this); // 准备好
            mMediaPlayer.setOnCompletionListener(this); //播放完成事件监听器
            mMediaPlayer.setOnBufferingUpdateListener(this); //缓冲变化
            mMediaPlayer.setOnErrorListener(this); //出错
            mMediaPlayer.setOnInfoListener(this); //音频信息
            mMediaPlayer.setWakeMode(MusicPlayerService.this, PowerManager.PARTIAL_WAKE_LOCK); //为MediaPlayer设置低级电源管理行为

            Class<MediaPlayer> clazz = MediaPlayer.class;
            Method method = clazz.getDeclaredMethod("setDataSource", String.class, Map.class);
            String path = "http://mp3.9ku.com/hot/2007/11-01/91161.mp3";  //音乐文件
            Log.e(TAG, "playMusic: startPlay-->: ID: ,PATH:" + path);
            method.invoke(mMediaPlayer, path, null);

            mMediaPlayer.prepareAsync();
        } catch (Exception e) {
            e.printStackTrace();

        }
    }

    /**
     * 暴露给代理Binder的 开始播放 的方法
     */
    public void startMusic() {
        Log.d(TAG, "startMusic: ");
        mMediaPlayer.start();
    }

    /**
     * 暴露给代理Binder的 停止播放
     */
    public void stopMusic() {
        mMediaPlayer.stop();
    }

    /**
     * 暴露给代理Binder的 暂停播放
     */
    public void pause() {
        Log.d(TAG, "pause: ");
        mMediaPlayer.pause();
    }

    /**
     * MediaPlayer 初始化完成
     *
     * @param mediaPlayer
     */
    @Override
    public void onPrepared(MediaPlayer mediaPlayer) {
        Log.d(TAG, "onPrepared: MediaPlayer 初始化完成  ");
    }


    /**
     * 缓冲百分比
     */
    @Override
    public void onBufferingUpdate(MediaPlayer mp, int percent) {
        Log.d(TAG, "onBufferingUpdate:  mp " + mp + " percent " + percent);
    }


    /**
     * 播放完成调用
     */
    @Override
    public void onCompletion(MediaPlayer mp) {
        Log.d(TAG, "onCompletion:  mp " + mp);
    }

    /**
     * 播放失败
     */
    @Override
    public boolean onError(MediaPlayer mp, int event, int extra) {
        Log.d(TAG, "onError:  mp " + mp + " extra " + extra + " event " + event);
        return false;
    }

    /**
     * 获取音频信息
     */
    @Override
    public boolean onInfo(MediaPlayer mp, int event, int extra) {
        Log.d(TAG, "onInfo:  mp " + mp + " event " + event + " extra " + extra);
        return false;
    }

    /**
     * 与Activity解除绑定，即Activity销毁时回调的生命周期方法
     */
    @Override
    public boolean onUnbind(Intent intent) {
        Log.d(TAG, "onUnbind: intent " + intent);
        return super.onUnbind(intent);
    }

    @Override
    public void onDestroy() {
        Log.d(TAG, "onDestroy: ");
        super.onDestroy();
    }
}

2.代理类，将所有播放相关的暴露给Activity

public class MusicPlayerBinder extends Binder {
    private final MusicPlayerService mService;

    public MusicPlayerBinder(MusicPlayerService musicPlayerService) {
        this.mService = musicPlayerService;
    }

    public void startMusic() {
        mService.startMusic();
    }

    public void stopMusic() {
        mService.stopMusic();
    }

    public void pause() {
        mService.pause();
    }
}

3.Activity 绑定Service，操作音频文件

public class MusicPlayerActivity extends AppCompatActivity implements View.OnClickListener {

    private String TAG = "Music-->log--> MusicPlayerActivity";

    private MusicPlayerBinder mBinder;
    private MusicPlayerServiceConnection mConnection;

    @Override
    protected void onDestroy() {
        super.onDestroy();

        Log.d(TAG, "onDestroy: ");
        unbindService(mConnection);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_music_player);

        initViews();
        openService();

    }

    private void initViews() {
        Button btnStart = findViewById(R.id.music_btn_start);
        Button btnPause = findViewById(R.id.music_btn_pause);

        btnStart.setOnClickListener(this);
        btnPause.setOnClickListener(this);
    }

    /**
     * 采用两种方式与Service建立连接
     * startService ：使Service长期在后台存在，不受Activity生命周期的影响
     * bindService ：使Activity能拿到Service的代理对象，能对Service进行操作
     */
    private void openService() {
        Intent intent = new Intent(this, MusicPlayerService.class);
        startService(intent);

        mConnection = new MusicPlayerServiceConnection();
        bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
    }

    @Override
    public void onClick(View v) {
        int i = v.getId();
        if (i == R.id.music_btn_start) {
            mBinder.startMusic(); //播放音乐
        } else if (i == R.id.music_btn_pause) {
            mBinder.pause(); // //暂停播放
        }
    }


    /**
     * Service绑定成功后的监听
     * MusicPlayer Service Connection
     */
    private class MusicPlayerServiceConnection implements ServiceConnection {
        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {
            Log.d(TAG, "onServiceConnected: ");
            if (null != service) {
                if (service instanceof MusicPlayerBinder) {
                    mBinder = (MusicPlayerBinder) service;
                    Log.d(TAG, "onServiceConnected: mBinder " + mBinder);
                }
            }
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
        }
    }
}

4.注意

1.权限

<uses-permission android:name="android.permission.INTERNET" />
<!-- 系统锁的机制, 只要有人拿着这个锁,系统就无法进入休 Service播放音乐，需要此权限-->
<uses-permission android:name="android.permission.WAKE_LOCK" />

2.Android9.0手机不做htts校验

 

参考

Android开发之MediaPlayer详解

有关Service的startService与bindService在各种情形下生命周期的变化