MediaBrowserServiceCompat 서비스에 바인딩 할 수 없습니다

Question

내 코드는 매우 간단합니다. 단지 MediaBrowserServiceCompat를 사용하여 음악 서비스에 바인딩하고 싶습니다. 실제로 더 중요한 프로그램을 가지고 있으므로 모든 중요하지 않은 부분을 작게 만들려고했습니다. 나는 다음과 같은 오류가 발생합니다 :

08-27 11:31:30.848 12214-12214/com.example.android.newcheck E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.android.newcheck, PID: 12214 java.lang.RuntimeException: Unable to bind to service com.example.android.newcheck.MusicStreamService@8c043ff with Intent { act=android.media.browse.MediaBrowserService cmp=com.example.android.newcheck/.MusicStreamService }: java.lang.NullPointerException: Attempt to invoke interface method 'android.os.IBinder android.support.v4.media.MediaBrowserServiceCompat$MediaBrowserServiceImpl.onBind(android.content.Intent)' on a null object reference at android.app.ActivityThread.handleBindService(ActivityThread.java:3847) at android.app.ActivityThread.access$2200(ActivityThread.java:221) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1887) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:158) at android.app.ActivityThread.main(ActivityThread.java:7224) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120) Caused by: java.lang.NullPointerException: Attempt to invoke interface method 'android.os.IBinder android.support.v4.media.MediaBrowserServiceCompat$MediaBrowserServiceImpl.onBind(android.content.Intent)' on a null object reference at android.support.v4.media.MediaBrowserServiceCompat.onBind(MediaBrowserServiceCompat.java:613) at android.app.ActivityThread.handleBindService(ActivityThread.java:3834) at android.app.ActivityThread.access$2200(ActivityThread.java:221)  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1887)  at android.os.Handler.dispatchMessage(Handler.java:102)  at android.os.Looper.loop(Looper.java:158)  at android.app.ActivityThread.main(ActivityThread.java:7224)  at java.lang.reflect.Method.invoke(Native Method)  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120) 

내가 주로 유튜브에 이안 호수 강의를 사용하고 그가 말한 모든 것을했다하지만 난이 오류가 왜, 내가 온라인 답을 찾으려고하지만 찾을 수 없습니다 모른다 어떤 대답이든. 도움을 주셔서 감사합니다.

AndroidManifest를 :

<service 
     android:name=".MusicStreamService" 
     android:exported="true"> 
     <intent-filter> 
      <action android:name="android.media.browse.MediaBrowserService" /> 
     </intent-filter> 
    </service> 

MainActivity :

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    MediaBrowserCompat mediaBrowser = new MediaBrowserCompat(MainActivity.this, new ComponentName(MainActivity.this, MusicStreamService.class), 
      new MediaBrowserCompat.ConnectionCallback() { 
       @Override 
       public void onConnected() { 
        Log.v("MainActivity","connected"); 
       } 
       @Override 
       public void onConnectionSuspended() { 
        super.onConnectionSuspended(); 
       } 
       @Override 
       public void onConnectionFailed() { 
        super.onConnectionFailed(); 
       } 
      }, null); 
    mediaBrowser.connect(); 
    Button click = (Button) findViewById(R.id.button); 
    click.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      startService(new Intent(MainActivity.this, MusicStreamService.class)); 
     } 
    }); 
} 

MusicStreamService :

public class MusicStreamService extends MediaBrowserServiceCompat { 
@Nullable 
@Override 
public BrowserRoot onGetRoot(@NonNull String clientPackageName, int clientUid, @Nullable Bundle rootHints) { 
    Log.v("***********", "getroot"); 
    return new BrowserRoot(getString(R.string.app_name), // Name visible in Android Auto 
      null); // Bundle of optional extras 
} 

@Override 
public void onLoadChildren(@NonNull String parentId, @NonNull Result<List<MediaBrowserCompat.MediaItem>> result) { 
    Log.v("*********", "one step before connect2"); 
    result.sendResult(null); 
} 

@Override 
public void onCreate() { 
    MediaSessionCompat mediaSession = new MediaSessionCompat(this, MusicStreamService.class.getSimpleName()); 
    setSessionToken(mediaSession.getSessionToken()); 
    mediaSession.setFlags(MediaSessionCompat.FLAG_HANDLES_MEDIA_BUTTONS | 
      MediaSessionCompat.FLAG_HANDLES_TRANSPORT_CONTROLS); 
    mediaSession.setActive(true); 
} 

Answer 1

내가 MusicStreamService 클래스에서에서 onCreate 메소드에서() super.onCreate를 작성 잊어 버렸습니다. 해결되었습니다.