Camera.PreviewCallback equivalent in Camera2 API

Is there any equivalent for Camera.PreviewCallback in Camera2 from API 21,better than mapping to a SurfaceTexture and pulling a Bitmap ? I need to be able to pull preview data off of the camera as YUV?

You can start from the Camera2Basic sample code from Google.

You need to add the surface of the ImageReader as a target to the preview capture request:

//set up a CaptureRequest.Builder with the output Surface
mPreviewRequestBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
mPreviewRequestBuilder.addTarget(surface);
mPreviewRequestBuilder.addTarget(mImageReader.getSurface());

After that, you can retrieve the image in the ImageReader.OnImageAvailableListener:

private final ImageReader.OnImageAvailableListener mOnImageAvailableListener = new ImageReader.OnImageAvailableListener() {
    @Override
    public void onImageAvailable(ImageReader reader) {
        Image image = null;
        try {
            image = reader.acquireLatestImage();
            if (image != null) {
                ByteBuffer buffer = image.getPlanes()[0].getBuffer();
                Bitmap bitmap = fromByteBuffer(buffer);
                image.close();
            }
        } catch (Exception e) {
            Log.w(LOG_TAG, e.getMessage());
        }
    }
};

To get a Bitmap from the ByteBuffer:

Bitmap fromByteBuffer(ByteBuffer buffer) {
    byte[] bytes = new byte[buffer.capacity()];
    buffer.get(bytes, 0, bytes.length);
    return BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
}