Android MediaPlayer无法在API 26+上播放音乐

Question

我有一个可以为用户播放音乐的应用，当我在运行API 25或更高版本的设备上进行测试时，此代码在运行Android且设备达到API 25的设备上可以正常运行，音乐也不会播放并且不会显示错误消息，是使用API​​ 28设备时的日志。

我尝试过的事情：

• MediaPlayer.setAudioStreamType（int streamtype）已弃用，因此我为26以上的API实现了AudioAttributes
• 不同类型的mp3文件，但它们在api 25及以下版本中都发挥相同的作用，当我尝试使用API​​ 26在设备或仿真器上进行任何操作

• 在文档和示例中进行搜索，但是看起来都一样，我的代码也没什么不同

  private void playMusic() {
  try {
      mMediaPlayer.reset();
  
      // For Android API 26 (Android 8 Oreo) and newer, specify AudioAttributes.
      if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
          Log.d("Record", "setAudioAttributes()");
          AudioAttributes.Builder builder = new AudioAttributes.Builder();
          builder.setUsage(AudioAttributes.USAGE_MEDIA);
          builder.setContentType(AudioAttributes.CONTENT_TYPE_MUSIC);
          AudioAttributes attributes = builder.build();
          mMediaPlayer.setAudioAttributes(attributes);
  
      } else {
          Log.d("Record", "setAudioStreamType()");
          mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
      }
  
      mMediaPlayer.setDataSource(String.format("http://www.server.com/mp3/%s.mp3", mp3File));
      mMediaPlayer.prepareAsync();
      mMediaPlayer.start();
  
  } catch (IOException e) {
      Log.d("Record", "error playing mp3");
      e.printStackTrace();
  }
  }
  

日志

2019-04-04 17:51:38.911 2947-24864/com.roneskinder.karaoke 
V/MediaPlayer: resetDrmState:  mDrmInfo=null mDrmProvisioningThread=null mPrepareDrmInProgress=false mActiveDrmScheme=false
2019-04-04 17:51:38.911 2947-24864/com.roneskinder.karaoke V/MediaPlayer: cleanDrmObj: mDrmObj=null mDrmSessionId=null
2019-04-04 17:51:38.913 2947-3054/com.roneskinder.karaoke D/EGL_emulation: eglMakeCurrent: 0xe830ce20: ver 3 0 (tinfo 0xe8315bd0)
2019-04-04 17:51:38.915 2947-24864/com.roneskinder.karaoke V/MediaHTTPService: MediaHTTPService(android.media.MediaHTTPService@aa03fa3): Cookies: null
2019-04-04 17:51:38.920 2947-4147/com.roneskinder.karaoke V/MediaHTTPService: makeHTTPConnection: CookieHandler (java.net.CookieManager@ead45b3) exists.
2019-04-04 17:51:38.920 2947-4147/com.roneskinder.karaoke V/MediaHTTPService: makeHTTPConnection(android.media.MediaHTTPService@aa03fa3): cookieHandler: java.net.CookieManager@ead45b3 Cookies: null

Answer 1

You need to define a res/xml/network_security_config.xml and permit HTTP for that host:

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="true">server.com</domain>
    </domain-config>
</network-security-config>

That network_security_config.xml also needs to be referenced in the Manifest.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest
    ...>
    <application
        android:networkSecurityConfig="@xml/network_security_config"
        ...>
            ...
    </application>
</manifest>

The SDK documentation explains it all in detail - and this applies to all network traffic an app creates.

Instead of lowering the security standards, upgrading the connection to HTTPS should be preferred.

---

And concerning that one deprecated method .setAudioStreamType(), use .setAudioAttributes() instead - as your code already does. It does not seem to be the "main problem" here; verified that.

Answer 2

Please use this code.

MediaPlayer player = new MediaPlayer();

player.setDataSource("http://www.server.com/mp3/%s.mp3");
player.setLooping(false);
player.setAudioStreamType(AudioManager.STREAM_MUSIC);
player.prepareAsync();

player.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {

                @Override
                public void onPrepared(MediaPlayer player) {
                    player.start();

                }

            });

Answer 3

只需在application标签中添加一行

<application
        .......
        android:usesCleartextTraffic="true"
        .......>
        .......
    </application>