Greetings:

DocuSign, the global leader in electronic signature, has a Java SDK with samples that show how to integrate with our web service using a number of technologies. We have samples using Ajax2, CXF, and even one optimized for an iPhone! And, best of all, you can develop using a free DocuSign sandbox.

If you want to add eSignature to your toolbox, check out our DevCenter: http://www.docusign.com/devcenter.