This article assumes that the necessary environment for the Java application that accesses IMS Database has been set up in advance. A brief description of the set up has been provided depending on the type of access for the Java application.
The question you need to have answered is:
- Does the Java app reside on z/OS on the same LPAR as the IMS database? Also referred to as “Local Access”
- Does the app reside on a different z/OS LPAR OR on a non-z/os(example Windows, linux or unix) platform? Also referred to as “Distributed Access”
Depending on the answer to the question above, make sure that the set up has been completed.
Use the Interactive Diagrams to understand what roles are involved in implementing the solutions
Local Access Set up
IMS Dependent Region Set up
Obtain the IMS Java Dependent region adapter and IMS Universal JDBC drivers. These are available as IMS Java components during installations. Details on how to get these files is described here under IMS Java On Demand Features
Make sure that the IMS region where the Java program is going to run has been set up, it is either Java Message Processing JMP or Java Batch Processing JBP.
IMS provides address spaces to execute system and application programs that use IMS services. These address spaces are called dependent regions. Learn more about IMS dependent regions here
How to set up the z/os environment for Java applications running in IMS
To set up the environment, set up the IMS database so that it is enabled for Java access. IMS Catalog set up is not absolutely required but it is helpful for JDBC access if it has been set up. Some IMS proclib dataset members need to be modified and the JMP procedure needs to be set up to point to them. This video describes the set up needed for applications to run in Java Message Processing (JMP) Region
Capture the database metadata class for the IMS Database
The Database metadata Java class is necessary because it describes the IMS PSBs, DBDs, segments, fields, relationships and data type information. If IMS Catalog has been set up, the database metadata is automatically captured, however it may still need to be enhanced.
IMS Explorer for Development is used to capture JDBC metadata so that IMS terms are mapped to relational making queries easier to model
IMS Explorer for Development is a no-charge product that installs on Windows operating system, downloadable from Download Page
To learn how to capture JDBC metadata for an IMS Database, watch this tutorial video
Model Input and Output Messages for IMS Transaction Manager
When input and output messages to IMS Transaction Manager are developed in Java, they need to be mapped so that TM understands how to process them.
It is important to note here that this video here describes input output messages for IMS Transaction manager to access an IMS database (not DB2 database). Learn the basics of Message queue processing for IMS TM and map the messages
Distributed Access Set up
- Set up open access infrastructure and optionally set up IMS catalog. Note that IMS catalog is not absolutely required but is recommended so that JDBC programming is easier.
More details on how to set up the infrastructure needed on z/OS in order to allow distributed access is documented here and setting up IMS Catalog has been documented here
- Capture the database metadata class as described above
- Obtain the IMS Universal JDBC Drivers and the Universal Database Resource Adapters available as a web download here
- Use IMS Explorer for Development to Visualize the database and model queries to be used in the Java application
To learn more regarding the set up for Distributed or open access to IMS DB, watch these video tutorials