Understanding WSDL

WSDL, Web Services Description Language, is a specification that describes XML based services. It provides a way for the service provider to describe the services as a set of endpoints. It gives details about how the service can be called, what parameters it can take, and what response it provides. There are several programs that can convert from Java to WSDL and WSDL to Java (or any other programming language, for that matter).

WSDL has six major elements that define the network service...

• types: provides data type definitions used to describe the messages exchanged.

• message: represents an abstract definition of the data being transmitted. A message consists of logical parts, each of which is associated with a definition within some type system.

• porttype: represents set of abstract operations. Each operation refers to an input message and output messages.

• binding: specifies concrete protocol and data format specifications for the operations and messages defined by a particular porttype.

• port: specifies an address for a binding, thus defining a single communication endpoint.

• service: used to aggregate a set of related ports.

For more details on WSDL, visit http://www.w3.org/TR/wsdl

The following section shows how to create a web service and displays the WSDL generated for that web service.