If you want to use iText on Android or the Google App Engine, you need to use iTextG. iTextG is almost identical to iText, except that it only uses classes that are white-listed by Google. All references to
javax.nio and other "forbidden" packages have been removed. You can download the source code and binaries from the release page on GitHub. As there are no dependencies on classes that aren't supported on Android in the PDF/A and XML Worker packages, you can download the Java version of these projects.
Currently, we don't offer iTextG on the Central Maven Repository.