Designing and Programming CICS Applications

Part III. The CICS Java Component

One of the KanDoIT company’s aims is to give its customers the ability to easily check their accounts using the Web without requiring any special client application software. The solution will connect to the existing business logic component, retrieve account data, and return a dynamically generated web page.

The business logic to retrieve customer account records is already in place—it’s the set of NACTnn COBOL programs we developed elsewhere in the book. Because we have designed it in the way we have, we will be able to reuse it for the Web.

How do we go about creating such a web application and benefit from the power of CICS on the mainframe? CICS TS for OS/390 Version 1.3 now supports the Java programming language and the Internet Inter-ORB Protocol (IIOP), which is part of the Common Object Request Broker Architecture (CORBA). These technologies are ideal for this type of application. Java allows development of applications that can run on any platform with a Java Virtual Machine (JVM). CORBA lets Java objects communicate with other objects across the Internet. This is exactly what we want to achieve: to expose our existing business logic to the outside world for any remote client that knows how to invoke its methods (subject to security constraints).

In this part we describe how to wrapper the existing COBOL CICS application using CICS Java classes, how to encapsulate the customer account as a CORBA object and how to configure CICS to route requests ...