Overview of the CICS Java component

This is a sample CICS Java program and describes how to write an IDL definition which enables you to use a CORBA IIOP connection, a Java program using the CICS Java classes to interact with an existing COBOL application, and how to export those classes to a CICS region to retrieve the customer data from the VSAM files.

Full details about setting up this sample is provided in Chapter 7 of "Designing and Programming CICS Applications".

Note: This code does not demonstrate all the techniques required for a large application. It is not a template and should not be used as the foundation for your next mission critical application.

Prerequisites

To run the CICS Java component you need:

  • VisualAge for Java Enterprise Edition Version 3 (you could use version 2 provided that you import the ET/390 toolkit to export and bind the Java application to the CICS region).
  • JDK 1.1.8 or later. Note: that you need JDK 1.2 to run the code in the MQSeries part of the book.
  • NFS Maestro

Writing and testing the CICS Java component

The following instructions are an abbreviated version of the procedure found in Chapter 7 of "Designing and Programming CICS Applications".

  1. Setting up the VisualAge for Java environment. VisualAge for Java Enterprise Edition Version 3.0 includes the CICS ORB and JCICS classes. To ensure that you are using these classes you need to add them as a feature. To do this select File, Quickstart, Feature Add Feature and click OK. From the list select JCICS Application Programming Library 3.0 and click OK.
  2. Configuring an ET/390 host environment in VisualAge for Java. There is a sample host.dat file in the /Corba Server directory.
  3. Creating and compiling the IDL definition. The file (accountObject.idl) that you can use is in the directory \Corba Server\IDLs\CICS.ADP.IIOP.Server\AccountIDL.
  4. Writing the server implementation class. The files for this part are founds in \Corba Server\Java Source\Corba Server\accountObject.
  5. Exporting and binding the sever application to a CICS region. The accountObject package now needs to be deployed in a CICS region. ET/390 uses FTP to export class files on OS/390. You should have already mounted a drive on your machine using an NFS client, which points to your host. Check that your CICS region has the correct parameters defined, See “Configuring the CICS Java component” in Appendix A of "Designing and Programming CICS Applications" for the details about setting up the sample definitions on OS/390.
  6. Creating a CORBA client to test the CORBA server code. This confirms that the code you have written works.

At the end of Part III of the book you will have created the server code using IIOP, to complete the job you need to create the client code described in Part IV of "Designing and Programming CICS Applications".