GwtUpload project
com.googlecode.gwtupload :
gwtupload-project
GWTUpload is a library for uploading files to web servers,
showing a progress bar with real information about the process (file size, bytes transferred, etc).
It uses ajax requests to ask the web server for the upload progress.
It has two components written in java, the server side with servlet and utility classes,
and the client side that is compiled into javascript using gwt.
GWTUpload-gae is a library with aditional classes needed for using GwtUpload in Google Application Engine (GAE).
JSUpload is the client library but compiled and exported into javascript,
so users without Gwt skills can use it directly in their web pages.
It includes a bunch of useful examples to learn how to use the library and see its features.
JarCasting