We don't currently support some of the more elaborate AR API's introduced by Google/Apple but we do support placing a camera view finder right into your app with a new cn1lib: https://github.com/codenameone/CameraKitCodenameOne
Since this is implemented in a library you can effectively edit the native code and add functionality as needed.
The original answer is out of date by now I'm keeping the original answer below for reference:
You can record video or take a photo with Codename One.
However, augmented reality type applications where you can place elements on top of the camera viewfinder are currently not supported by Codename One. This functionality is somewhat platform specific and hard to implement in a portable manner.