判断设备是否具备摄像头

 private boolean hasCamera(){
  PackageManager pm = this.getPackageManager();
  return pm.hasSystemFeature(PackageManager.FEATURE_CAMERA)//是否有后置相机
    || pm.hasSystemFeature(PackageManager.FEATURE_CAMERA_FRONT)//是否有前置相机
    || Build.VERSION.SDK_INT < Build.VERSION_CODES.GINGERBREAD
    || Camera.getNumberOfCameras() > 0;
 }