As @GiuliaDiFederico said, "of course it's possible" (with WSDL2), showing a good source link about how to do. @DonalFellows, by other hand, does not encouraged the use of WSDL...
I think the use of WSDL is a question of
- FORMALIZATION LEVEL: with WSDL you can express more formally all relevant details of your webservice.
- STABILITY LEVEL: if you need long term contracts, and avoid risks of changes in the enviroment where your webservice is exposed, WSDL helps to mantain stability.
- NEED FOR STANDARDS: if customers prefer webservices that can be said "standard compliant", use standards. The only one is W3C, and W3C requires XML, SOAP and WSDL.
