Broker implements non-web-service interface to new Web service

In this Web service scenario, the broker provides backward compatibility for existing non-web-service clients to invoke a new Web services implementation provided by a SOAP toolkit.

The diagram shows an existing client associated with an existing interface. The interface definition file is imported to a message set. A WSDL file is generated from the message set and used to generate a new Web service. The message set is deployed to a flow in a broker. At runtime the flow interacts with the original existing client and the new Web service.

Key to symbols:

This diagram describes the symbols used in the other diagrams, and is not described here because those diagrams each have their own descriptions.

Possible uses

You want to migrate an application to a Web service implementation, for example an EJB implementation hosted by an application server to offer better scalability.

However, a significant number of your users have existing clients which cannot be immediately replaced. The broker allows the existing clients to use the new Web service implementation.

Design steps

  1. Create a message set for the business messages, possibly by importing an existing interface definition such as a C header file or COBOL copybook.
  2. Generate a WSDL definition from the message set.
  3. Use a SOAP toolkit or application server to create a suitable Web services implementation based on the WSDL
  4. Develop a message flow to mediate between the original existing client and the new Web service.

Runtime

Your message flow receives a request from the existing client, converts it into a Web services request and invokes the Web service. The response from the Web service is converted into a form understood by the existing client.

Related concepts
Web services, WSDL and message flows
Broker calls existing Web service
Broker implements new Web service interface
Broker implements existing Web service interface