Ask multiple runtime permissions

MainActivity.java

public class MainActivity extends AppCompatActivity {
        private final int PERMISSION_REQUEST_CODE = 1;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);

            setContentView(R.layout.activity_main);
            
            // list of permissions
            String[] permission = new String[]{
                    Manifest.permission.CAMERA,
                    Manifest.permission.WRITE_EXTERNAL_STORAGE,
                    Manifest.permission.RECORD_AUDIO};

            // checking permissions, if granted or not
            if ((ContextCompat.checkSelfPermission(mContext, permission[0])) +
                    (ContextCompat.checkSelfPermission(mContext, permission[1])) +
                    (ContextCompat.checkSelfPermission(mContext, permission[2]))
                    != PackageManager.PERMISSION_GRANTED) {
                ActivityCompat.requestPermissions(this, permission, PERMISSION_REQUEST_CODE);
            } else {
                callMethodToRunTask();
            }
        }

        @Override
        public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
            switch (requestCode) {
                case PERMISSION_REQUEST_CODE:
                    // If request is cancelled, the result arrays are empty.
                    if (grantResults.length > 0
                            && (grantResults[0] + grantResults[1] + grantResults[2]) == PackageManager.PERMISSION_GRANTED) {
                        callMethodToRunTask();
                    }
            }
        }

        public void callMethodToRunTask() {
            // implement code 
        }
    }