Introduction to COBOL Web Services

This chapter introduces Web Services and the different ways that you can use Server Express to expose a COBOL application as a Web service.

In this Chapter

Overview

"Web Services" is the name of a set of standards and mechanisms enabling software components to be invoked across the Web. The components themselves are called Web services. An application using a Web service (a client application) can invoke it and pass data to and from it very easily, because all communication between them is in the form of XML files sent using a standard protocol such as HTTP. This means the client application has no need to know details of how the component is deployed, what language it is in, and so on.

In theory, exposing a component as a Web service means it can be invoked across the Web by anyone in the world. For example, a credit card company might provide a Web service to be called by retailers to validate card details. They are often used across companies' intranets, for use in internal applications and as a means of integrating disparate internal applications.

Web Services is built around three standards that define the format of the XML files needed to link clients to services:

For the latest specifications of WSDL, SOAP, HTTP and UDDI, see the World Wide Web consortium Web site.

COBOL Web Services

There are several ways you can use Server Express to expose COBOL programs as Web services:

For a comparison of the advantages of the different methods, see the chapter Application Extension with Distributed Computing.

WS-I Compliance

The Web services that the Interface Mapping Toolkit creates are WS-I Basic Profile 1.0 compliant. The Web Services Interoperability Organization (WS-I) is an open industry organization chartered to promote Web services interoperability across platforms, operating systems, and programming languages. The WS-I Basic Profile is a document containing a set of assertions and rules which vendors and end-users should conform to in order to maximize the interoperability of their web services across various platforms.

Web services created with tools which conform to the WS-I Basic Profile are more likely to interoperate with third party web service toolsets ensuring seamless integration across the internet/intranet. For further details, including the most up to date version of the Basic Profile as well as testing tools, visit the Web Services Interoperability Organization Web site.