Resteasy has problems in the way Providers are looked up. In my case, my REST-Client had to be WAR1 (deployed on server1) talking to RESTful implementation in WAR2 deployed on server 2.
The big problem I had was that ResteasyProviderFactory tries to scan all the jars for Providers and registered them. The IO operations (getResource() on Classloader) locks couple of JAR files in the server process because of which the undeployment of WAR1 (client) was failing
Hope this helps
