Vijay Oruganty has been kind enough to provide a Java upload handler for the YUI Rich text image uploader.
I've attached the Eclipse project here.
Here is Vijay's comments on the project:
[the attached file] has the whole eclipse project including the required libraries to build the project using ant. It has the compiled classes and the binary war (lib/ic_editor.war). The main java source (the upload handler) is iic_editor/src/com/hrbfa/iceditor/controller/RequestProcessor.java',
Feel free to comment or ask questions about the project on this post.