기기에 카메라가없는 경우 Android에서 검은 색 배경색이 표시됨

최근에 CCTV 카메라 앱을 사용했는데 기기에 카메라가 없으면이 logcat 이 표시 되고 앱이 종료됩니다.

java.lang.RuntimeException: Unable to start activity ComponentInfo{kr.co.iosystem.blackeyeonandroid/kr.co.iosystem.blackeyeonandroid.BlackEyeActivity}: java.lang.NullPointerException
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2184)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
    at android.app.ActivityThread.access$800(ActivityThread.java:135)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:136)
    at android.app.ActivityThread.main(ActivityThread.java:5001)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:515)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
    at dalvik.system.NativeStart.main(Native Method)
 Caused by: java.lang.NullPointerException
    at org.webrtc.PeerConnectionFactory.createVideoSource(PeerConnectionFactory.java:111)
    at kr.co.iosystem.blackeyeonandroid.BlackEyeActivity.onCreate(MainActivity.java:235)
    at android.app.Activity.performCreate(Activity.java:5231)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2148)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233) 
    at android.app.ActivityThread.access$800(ActivityThread.java:135) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:136) 
    at android.app.ActivityThread.main(ActivityThread.java:5001) 
    at java.lang.reflect.Method.invokeNative(Native Method) 
    at java.lang.reflect.Method.invoke(Method.java:515) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601) 
    at dalvik.system.NativeStart.main(Native Method) 

내 소스 MainActivity.java

@Override
protected void onCreate(final Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   setContentView(R.layout.activity_main);

   String nameOfFrontFacingDevice = VideoCapturerAndroid.getNameOfFrontFacingDevice();
   String nameOfBackFacingDevice = VideoCapturerAndroid.getNameOfBackFacingDevice();
   VideoCapturerAndroid capturer = VideoCapturerAndroid.create(nameOfFrontFacingDevice);
   . 
   . 
   . 
   }

카메라가 없다면. capturer이 반환 null그래서 나는 테스트

if (capturer == null || capturer.equals("") == true) {
   try {
      rebootProcess = Runtime.getRuntime().exec(new String[]{"su", "-c", "reboot"});
   } catch (IOException e) {
      e.printStackTrace();
    }
 }

앱을 실행합니다. 장치를 재부팅했지만 카메라가없는 경우 검정색 배경을 표시하고 싶습니다.

카메라에 연결되어 있으면 GLSurfaceView

glview = (GLSurfaceView) findViewById(R.id.glview);
VideoRendererGui.setView(glview, null) ;
try {
     . . . .
} catch {
}

아마도 조각을 사용합니까? 저에게 조언을 부탁드립니다. 나는 생각한다

if (capturer == null || capturer.equals("") == true) {
   // showing black background ??..
  } 

근데 검은 색 배경 부분은 잘 모르겠어요.

감사.

@최신 정보

MainActivity.java (전체 생성시)

@Override
protected void onCreate(final Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    String nameOfFrontFacingDevice = VideoCapturerAndroid.getNameOfFrontFacingDevice();

    if (nameOfFrontFacingDevice != null) {
        VideoCapturerAndroid capturer = VideoCapturerAndroid.create(nameOfFrontFacingDevice);

        MediaConstraints videoConstraints = new MediaConstraints();
        VideoSource videoSource = peerConnectionFactory.createVideoSource(capturer, videoConstraints);
        localVideoTrack = peerConnectionFactory.createVideoTrack(VIDEO_TRACK_ID, videoSource);

        glview =(GLSurfaceView) findViewById.(R.id.showing);
        VideoRendererGui.setView(glview, null);
        try {
            renderer = VideoRendererGui.createGui(0,0,100,100, VideoRendererGui.ScalingType.SCALE_ASPECT_FILL, true);
            localVideoTrack.addRenderer(renderer);
        } catch (Exception e) {
             e.printStackTrace();
        }

        mediaStream = peerConnectionFactory.createLocalMediaStream(LOCAL_MEDIA_STREAM_ID);
        mediaStream.addTrack(localVideoTrack);
    } else {
        //space
    }

나는 당신의 조언을 내 소스를 변경했습니다. 그러나 발생nullpointerException

다른 부분에서. 프로그래밍 방식으로 어떻게 할 수 있습니까?