java.lang.RuntimeException：无法启动服务

Question

我刚刚将我的应用程序更新为targetSdkVersion 26，并且出现了以下问题：

java.lang.RuntimeException: Unable to start service 
java.lang.RuntimeException: setAudioSource failed.
At the logcat it says that the problem is in my service class, in the 

遵循两行代码：

    mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
    and

   public int onStartCommand(Intent intent, int flags, int startId) {
         startRecording();

  

RecordingService

public class RecordingService extends Service {

    private static final String LOG_TAG = "RecordingService";

    private String mFileName = null;
    private String mFilePath = null;

    private MediaRecorder mRecorder = null;

    private DBHelper mDatabase;

    private long mStartingTimeMillis = 0;
    private long mElapsedMillis = 0;
    private int mElapsedSeconds = 0;
    private OnTimerChangedListener onTimerChangedListener = null;
    private static final SimpleDateFormat mTimerFormat = new SimpleDateFormat("mm:ss", Locale.getDefault());

    private Timer mTimer = null;
    private TimerTask mIncrementTimerTask = null;



    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    public interface OnTimerChangedListener {
        void onTimerChanged(int seconds);
    }

    @Override
    public void onCreate() {
        super.onCreate();
        mDatabase = new DBHelper(getApplicationContext());
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
         startRecording();
        return START_STICKY;
    }

    @Override
    public void onDestroy() {
        if (mRecorder != null) {
            stopRecording();
        }

        super.onDestroy();
    }

    public void startRecording() {


        setFileNameAndPath();

        mRecorder = new MediaRecorder();
        mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
        mRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
        mRecorder.setOutputFile(mFilePath);
        mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);

        try {
            mRecorder.prepare();
            mRecorder.start();
            mStartingTimeMillis = System.currentTimeMillis();

            //startTimer();
            //startForeground(1, createNotification());

        } catch (IOException e) {
            Log.e(LOG_TAG, "prepare() failed");
        }
    }

    public void setFileNameAndPath(){
        int count = 0;
        File f;

        do{
            count++;

            mFileName = getString(R.string.default_file_name)
                    + " #" + (mDatabase.getCount() + count) + ".mp4";
            mFilePath = Environment.getExternalStorageDirectory().getAbsolutePath();
            mFilePath += "/SoundRecorder/" + mFileName;

            f = new File(mFilePath);
        }while (f.exists() && !f.isDirectory());
    }

    public void stopRecording() {
        mRecorder.stop();
        mElapsedMillis = (System.currentTimeMillis() - mStartingTimeMillis);
        mRecorder.release();
        Toast.makeText(this, getString(R.string.toast_recording_finish) + " " + mFilePath, Toast.LENGTH_LONG).show();

        //remove notification
        if (mIncrementTimerTask != null) {
            mIncrementTimerTask.cancel();
            mIncrementTimerTask = null;
        }

        mRecorder = null;

        try {
            mDatabase.addRecording(mFileName, mFilePath, mElapsedMillis);

        } catch (Exception e){
            Log.e(LOG_TAG, "exception", e);
        }
    }

    private void startTimer() {
        mTimer = new Timer();
        mIncrementTimerTask = new TimerTask() {
            @Override
            public void run() {
                mElapsedSeconds++;
                if (onTimerChangedListener != null)
                    onTimerChangedListener.onTimerChanged(mElapsedSeconds);
                NotificationManager mgr = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
                mgr.notify(1, createNotification());
            }
        };
        mTimer.scheduleAtFixedRate(mIncrementTimerTask, 1000, 1000);
    }

    //TODO:
    private Notification createNotification() {
        NotificationCompat.Builder mBuilder =
                new NotificationCompat.Builder(getApplicationContext())
                        .setSmallIcon(R.mipmap.ic_launcher)
                        .setContentTitle(getString(R.string.notification_recording))
                        .setContentText(mTimerFormat.format(mElapsedSeconds * 1000))
                        .setOngoing(true);

        mBuilder.setContentIntent(PendingIntent.getActivities(getApplicationContext(), 0,
                new Intent[]{new Intent(getApplicationContext(), MainActivity.class)}, 0));

        return mBuilder.build();
    }
}

问题出在哪里？

这是完整的Logcat

08-10 10:29:24.357 12325-12325/com.anastasios.notesrecording E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.anastasios.notesrecording, PID: 12325
    java.lang.RuntimeException: Unable to start service com.anastasios.notesrecording.RecordingService@fb79b63 with Intent { cmp=com.anastasios.notesrecording/.RecordingService }: java.lang.RuntimeException: setAudioSource failed.
        at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3491)
        at android.app.ActivityThread.-wrap20(Unknown Source:0)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1692)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6494)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
     Caused by: java.lang.RuntimeException: setAudioSource failed.
        at android.media.MediaRecorder.setAudioSource(Native Method)
        at com.anastasios.notesrecording.RecordingService.startRecording(RecordingService.java:84)
        at com.anastasios.notesrecording.RecordingService.onStartCommand(RecordingService.java:65)
        at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3474)
        at android.app.ActivityThread.-wrap20(Unknown Source:0) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1692) 
        at android.os.Handler.dispatchMessage(Handler.java:106) 
        at android.os.Looper.loop(Looper.java:164) 
        at android.app.ActivityThread.main(ActivityThread.java:6494) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)