MediaRecorderの問題。getFolderSize() : Exception_1 = java.lang.NullPointerException:

Question

こんにちは、
Androidプログラミングに関しての質問です。
MediaRecorder
以下の通りにコードを実施すると、一番下のエラーが出てしまいます。
カメラが3つついている端末を用いているため、それがエラーを引き起こしているのではないかと考えているのですが、対処方法がわかりません。
よろしくお願いします。

MainActivity

package com.morimoku.mediarecorder;

import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

import android.Manifest;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.os.Build;
import android.os.Bundle;


import android.view.View;
import android.widget.Button;
import android.widget.VideoView;

import static android.Manifest.permission.READ_EXTERNAL_STORAGE;

public class MainActivity extends AppCompatActivity  {
    private static final String TAG = "MainActivity";
    private static final int RECORD_REQUEST_CODE = 103;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        int Permission_All = 1;

        String[] Permissions = {Manifest.permission.RECORD_AUDIO, Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.CAMERA, READ_EXTERNAL_STORAGE, Manifest.permission.SYSTEM_ALERT_WINDOW,Manifest.permission.READ_EXTERNAL_STORAGE};
        if (!hasPermissions(this, Permissions)) {
            ActivityCompat.requestPermissions(this, Permissions, Permission_All);
        }
        VideoView videoView = findViewById(R.id.videoView1);
        Button button1 = findViewById(R.id.button_start);
        button1.setOnClickListener(new Button.OnClickListener() {

                                       @Override
                                       public void onClick(View view) {
                                           startService();
                                       }
                                   }
        );
    }


    public static boolean hasPermissions(Context context, String... permissions) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && context != null && permissions != null) {
            for (String permission : permissions) {
                if (ActivityCompat.checkSelfPermission(context, permission) != PackageManager.PERMISSION_GRANTED) {
                    return false;
                }
            }
        }
        return true;
    }
}
The part where it starts recording.

public class Recorder extends Service {

    public static final String CHANNEL_ID = "ForegroundServiceChannel";
    private static final int VIDEO_DURATION = 30 * 60 * 1000;
    private static final long VIDEO_FILESIZE = 1024 * 1024 * 1024;
    private Camera mCamera;
    private boolean isRecording = false;
    private MediaRecorder mMediaRecorder;
    private static String fileName = null;


    @Nullable
    @Override

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

    @Override
    public void onCreate() {
            super.onCreate();
            Log.d("debug","onCreate");

           }

    @RequiresApi(Build.VERSION_CODES.O)
    public int onStartCommand(Intent intent,int flags,int startId) {
        super.onStartCommand(intent, flags, startId);


        String input = intent.getStringExtra("inputExtra");
        createNotificationChannel();

        Intent notificationintent = new Intent(this, MainActivity.class);
        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, notificationintent, 0);
        //Foreground Service
        Notification notification = new NotificationCompat.Builder(this, CHANNEL_ID)
                .setSmallIcon(R.mipmap.ic_launcher)
                .setTicker(getString(R.string.app_name))
                .setAutoCancel(true)
                .setContentTitle(getString(R.string.app_name))
                .setContentIntent(pendingIntent)
                .setContentText(getString(R.string.app_name))
                .build();
        startForeground(1, notification);
        //動作を書き込む


        isRecording = true;
        mCamera = Camera.open();
        Camera.Parameters cameraParameters = mCamera.getParameters();
        cameraParameters.setFocusMode(Camera.Parameters.FOCUS_MODE_INFINITY);
        mCamera.setParameters(cameraParameters);
        mCamera.unlock();

        fileName = getExternalCacheDir().getAbsolutePath();
        fileName += "/audiorecordtest.3gp";

        mMediaRecorder = new MediaRecorder();
        mMediaRecorder.setCamera(mCamera);

        mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
        mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.DEFAULT);

        mMediaRecorder.setOutputFile(fileName);
        mMediaRecorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH));

        mMediaRecorder.setMaxDuration(VIDEO_DURATION);
        mMediaRecorder.setMaxFileSize(VIDEO_FILESIZE);

        try {
            mMediaRecorder.prepare();
            mMediaRecorder.start();
            Log.d("debug","startrecording");
        } catch (IOException ex) {
            ex.printStackTrace();

            stopForeground(true);

            mMediaRecorder.release();
            mCamera.lock();
            mCamera.release();

            isRecording = false;

            ((Vibrator) getSystemService(VIBRATOR_SERVICE)).vibrate(3000);

        }
        return START_STICKY;
    }

マニフェストの部分

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    <uses-feature android:name="android.hardware.Camera" android:required="true"></uses-feature>
    <uses-permission android:name="android.permission.VIBRATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
    <uses-permission android:name="android.permission.ACCESS_NOTIFICATION_POLICY"/>
    <uses-permission android:name="android.permission.CAMERA"/>
    <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
    <uses-permission android:name="android.permission.RECORD_AUDIO"/>
    <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

エラーメッセージ

E/Perf: Fail to get file list com.morimoku.driverecorder
    getFolderSize() : Exception_1 = java.lang.NullPointerException: Attempt to get length of null array
W/u.driverecorde: Accessing hidden method Landroid/view/View;->computeFitSystemWindows(Landroid/graphics/Rect;Landroid/graphics/Rect;)Z (greylist, reflection, allowed)
W/u.driverecorde: Accessing hidden method Landroid/view/ViewGroup;->makeOptionalFitsSystemWindows()V (greylist, reflection, allowed)
W/Gralloc3: mapper 3.x is not supported
W/AdrenoUtils: <ReadGpuID_from_sysfs:194>: Failed to open /sys/class/kgsl/kgsl-3d0/gpu_model
    <ReadGpuID:218>: Failed to read chip ID from gpu_model. Fallback to use the GSL path
D/debug: onCreate
E/libc: Access denied finding property "vendor.camera.hal1.packagelist"
I/Utils: getMaxFileSize: result=4020731904, free=4020731904, max files size=0
E/MediaRecorder: start failed: -22
D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.morimoku.driverecorder, PID: 10077
    java.lang.RuntimeException: Unable to start service com.morimoku.driverecorder.DriveRecorder@e0e277e with Intent { cmp=com.morimoku.driverecorder/.DriveRecorder (has extras) }: java.lang.RuntimeException: start failed.
        at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:4117)
        at android.app.ActivityThread.access$1800(ActivityThread.java:225)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1897)
        at android.os.Handler.dispatchMessage(Handler.java:107)
        at android.os.Looper.loop(Looper.java:359)
        at android.app.ActivityThread.main(ActivityThread.java:7418)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:935)
     Caused by: java.lang.RuntimeException: start failed.
        at android.media.MediaRecorder.start(Native Method)
        at com.morimoku.driverecorder.DriveRecorder.onStartCommand(DriveRecorder.java:116)
        at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:4099)
        at android.app.ActivityThread.access$1800(ActivityThread.java:225) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1897) 
        at android.os.Handler.dispatchMessage(Handler.java:107) 
        at android.os.Looper.loop(Looper.java:359) 
        at android.app.ActivityThread.main(ActivityThread.java:7418) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:935) 

Answer 1

Android MediaRecorder の使い方を確認してください。今回はその記述例に問題があり、エラーが発生しました。MediaRecorderの部分の問題を解決したらエラーは出なくなりましたが、また新たな問題が起きました。今回の質問と大きく脱線するので、ここまでします。