Planning to use Web services

Before you can plan to use Web services in CICS®, you need to consider these questions for each application:
Do you plan to deploy your CICS application in the role of a service provider or a service requester?

You may have a pair of applications that you want to connect using CICS support for Web services. In this case, one application will be the service provider; the other will be the service requester.

Do you plan to use your existing application programs, or write new ones?
If your existing applications are designed with a well defined interface to the business logic, you will probably be able to use them in a Web services setting, either as a service provider or a service requester. However, in most cases, you will need to write a wrapper program that connects your business logic to the Web services logic.

If you plan to write new applications, you should aim to keep your business logic separated from your Web services logic, and, once again, you will need to write a wrapper program to provide this separation. However, if your application is designed with Web services in mind, the wrapper may prove to be simpler to write.

Do you intend to use SOAP messages?
SOAP is fundamental to the Web services architecture, and much of the support that is provided in CICS assumes that you will use SOAP. However, there may be situations where you wish to use other message formats. For example, you may have developed your own message formats that you want to deploy with the CICS Web services infrastructure. CICS allows you to do this, but you will not be able to use some of the functions that CICS provides, such as the Web services assistant, and the SOAP message handlers.
Do you intend to use the CICS Web services assistant to generate the mappings between your data structures and SOAP messages?
The assistant provides a rapid deployment of many applications into a Web services setting with little or no additional programming. And when additional programming is required, it is usually straightforward, and can be done without changing existing business logic.

However, there are cases which are better handled without using the Web services assistant. For example, if you have existing code that maps data structures to SOAP messages, there is no advantage in reengineering your application with the Web services assistant.

Do you intend to use an existing service description, or create a new one?
In some situations, you will be obliged to use an existing service description as a starting point. For example:
  • Your application is a service requester, and it is designed to invoke an existing Web service.
  • Your application is a service provider, and you want it to conform to an existing industry-standard service description.
In other situations, you may need to create a new service description for your application.
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