Codename One doesn't support the Android API. It uses Java but uses it's own API and GUI structure to allow for portability as Android is too big/complex to run on top of iOS and all of the other OS's supported by Codename One. See http://www.codenameone.com/blog/why-we-dont-support-the-full-java-api.html
You will need to rewrite your UI code using our API and quite possibly other code e.g. networking/storage. Since this is still Java you can reuse some of your code/skills.
We have a very experimental/preliminary tool for converting android project here: http://www.codenameone.com/blog/android-migration-tool.html
We are seeking feedback on it.