Well, today I have also faced exactly the same problem. But I can resolve this issue by starting the server in standalone mode with parameter as following:
standalone.bat --server-config=standalone-preview.xml
If you check the extentions in standalone.xml, which is under JBOSS_AS7/standalone/configuration you will found no webservice module to be loaded. Again, if you check standalone-preview.xml you will found webservice modules to load on server startup.
So by running your server using the mentioned command you will have your web service working. Enjoy exploring :)
- Shekh Morshed Akther