问如何在android中强制设置后置摄像头和关闭前置摄像头

EN

  Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            intent.putExtra(MediaStore.EXTRA_OUTPUT,
                    MediaStore.Images.Media.EXTERNAL_CONTENT_URI.toString());
            intent.putExtra("android.intent.extras.CAMERA_FACING", 0);
            // ******** code for crop image
            intent.putExtra("crop", "true");
            intent.putExtra("aspectX", 0);
            intent.putExtra("aspectY", 0);
            intent.putExtra("outputX", 200);
            intent.putExtra("outputY", 150);


            try {

                intent.putExtra("return-data", true);
                startActivityForResult(intent, PICK_FROM_CAMERA);

            } catch (ActivityNotFoundException e) {
                // Do nothing for now
            }

  @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {

        if (requestCode == PICK_FROM_CAMERA) {
            try {
                Bundle extras = data.getExtras();
                if (extras != null) {
                    photo = extras.getParcelable("data");                

                }

            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        }