Have you considered http://labs.vmware.com/flings/vix-java-toolkit
It claims
The VIX Java Toolkit allows Java developers to take advantage of the
VMware VIX API. This is a powerful API that allows for performing
in-guest operations on VMs running with vSphere, Workstation, Server,
and Player. Java developers who are writing code with the vSphere/VI
APIs will find this particularly useful as the vSphere API does not
currently provide any functionality for interacting with the guest
operating system. In addition, this is helpful for software testing as
well as systems administration.