Consuming REST service that doesn't offer WADL

Question

I need to work with a REST service that has a relatively simple and fixed (meaning predictably not very variant structure), yet I can't find a WADL anywhere on their site. I have previously worked with SOAP services, which had a decent WSDL and I used it to generate my Java classes to which my client app was marshalling the service data using Axiom2.

My question is: is there an easy way to reverse engineer a WADL with which to easily generate corresponding Java classes if the site is lacking one, using some implementation of JAX-RS (eg Jersey)? Another way to ask it is: given only a REST service, no WADL, and some form of JAX-RS, what is the easiest way to generate marshalled classes on the client side?

Currently, as the structure is simple, I do it the hard way of using straight DOM from Java SE ( org.w3c.dom ) to parse the document. It works fine but I do not like all the traversing I have to do within the document structure and I feel like I reinvented the wheel. I am sure there is a more elegant way.

Answer 1

If you're just doing this once why not just do it by hand? If you need to do this regularly then you may be out of luck wrt WADL (as an aside see: https://softwareengineering.stackexchange.com/questions/133145/should-i-use-wadl-to-describe-my-restful-api ).

Are you just trying to generate Java classes for the DTOs from the service? In this case you could take some sample XML from the service and use this to generate a possible XSD (maybe using trang ). Then use XJC to generate the corresponding Java classes.

Answer 2

If the REST service is implemented in Jersey, Jersey should auto generate the WADL at runtime. The default location is http://server:port/appcontextroot/application.wadl . If the REST service uses other implementation such as RESTEasy, you are out of luck. https://issues.jboss.org/browse/RESTEASY-166