The open source project was recently updated to support vSphere 5.1. For details, check out my blog:
http://www.doublecloud.org/2012/09/announcing-public-beta-of-vi-java-api-5-1-supporting-vsphere-5-1/
Steve, creator of vijava open source
yes, that is really nice API ,do you know where can i get the API docs?
Not really JavaDoc for the API but close enough to work on the Java API using it:
http://vijava.sourceforge.net/vSphereAPIDoc/ver51/ReferenceGuide/
Also, FAQ here: http://www.doublecloud.org/vmware-vsphere-api-and-sdk-faq/
Steve