It might be best to find the vApp in general using the query service, then see what it's properties are and then the properties of the VMs inside to find out what the current status is.
Also, as an FYI, there is a dedicated forum for the Java SDK here: https://communities.vmware.com/community/vmtn/developer/forums/vcloudsdkjava/content?filterID=contentstatus[published]~objecttype~objecttype[thread]
Or the API in a more general sense here: https://communities.vmware.com/community/vmtn/developer/forums/vcloudapi/content?filterID=contentstatus[published]~objecttype~objecttype[thread]