WSDL (Web Services Description Language) has become the standard way to describe the interface to a particular Web Service. Here we will start off with an explanation of the main sections that make up a WSDL file and its importance in a Web Service deployment.

Many people have deployed enterprise applications using a variety of technologies, such as J2EE and CORBA. One of the steps for exposing these applications as Web Services is to provide a WSDL description of this service. We will firstly show and discuss how one can describe an Enterprise Java Bean in WSDL. We will then have a look at how some commercial tools deal with the problem.

For a more complex example, we will look at how one can describe a CORBA IDL interface in WSDL. We will look at the issues, around multiple objects in a single Web Service and techniques for mapping CORBA IDL inheritance hierarchies to WSDL.