Webservice Description Language (WSDL)

              
Webservice Description Language (WSDL)

                Webservice is a software system designed to support interoperable machine to machine interaction over a network. In otherwords, it is a Client-Server model based application. WSDL is Webservice Description Language which is an XML based language that provides a model for describing webservices. The main advantage of the webservice is that we can pass values at run time. WSDL uses a certain standard format called SOAP which is Simple Object Access Protocol. The structure of SOAP has a Header, Body and Attachment.


      WSDL has Abstract wsdl on the server side and Concrete wsdl on the client side to perform machine readable description of the operations offered by the service.

        Abstract wsdl is the core of the web service. All services are defined in the abstract wsdl. It is a Server Side WSDL. Abstract wsdl contains only messages and operations. Abstract wsdl is used by SOAP Server. Request and reply operations are created with a port type.
        
            Concrete wsdl is the WSDL that allows a client to connect (and work with request/response) to a Web Server.It contains the metadata for sending a correct request and receiving correct response. Concrete wsdl contains messages, operations and transport specific information (JMS or Http). This is used by SOAP client.