Introduction to COBOL Web Services

This paper introduces the concept of Web Services.

Contents

Introduction

"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 - for example, whether it is a COM object or an EJB, what language it is in, and so on.

At the time of writing, Web Services is a relatively recent innovation. In theory, deploying 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. However, at the present time they are often used across companies' intranets, for use in internal applications and as a means of integrating disparate internal applications.

Web Services in Brief

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

For a detailed discussion of Web services and their benefits, see the white paper Web Services Concepts. For the latest specifications of WSDL, SOAP, and UDDI, see http://www.w3.org.

COBOL Web Services

The toolkits for creating and accessing Web services that are available today do not natively support COBOL. However, there are several ways you can use Net Express with these toolkits to deploy COBOL programs as Web services:

Which mechanism you use largely depends on which products you use in your organization. The Microsoft SOAP Toolkit can only be used to create Web services that are hosted under Microsoft Internet Information Server (IIS). If you use another Web server or are using an application server to host your Web services, you may want to take a look at Java-based toolkits. Of the three mechanisms mentioned, only the Net Express/Cape Clear integration has been designed specifically for creating COBOL Web services.