Mapping and transforming application data and JSON

You can write application programs to transform application binary data into JavaScript Object Notation (JSON) and vice versa. CICS® supports a number of high-level languages and provides a JSON assistant to map how the data is transformed during runtime processing. CICS uses the same technology for mapping application data to JSON messages, as part of the web services support.

Before you begin

You must have Java™ installed to run the JSON assistant. Transformations can be carried out either internally with CICS or by using a JVM server. If you use Java for the transformations, then you must have an Axis2 JVM server installed to transform application data and JSON. See Configuring a JVM server for Axis2 for more information.

About this task

The advantage of using this approach to transform application data to and from JSON is that CICS goes beyond the capabilities that are offered by a JSON parser. CICS can interpret the JSON and perform record-based conversions of the application data. Therefore, it is easier and faster for you to create applications that work with JSON by using this approach.

The CICS JSON assistant is a supplied utility that helps you to create the required mapping artifacts to transform application binary data to JSON or transform JSON to application binary data. The JSON assistant creates the artifacts in a bundle directory.

Procedure

  1. Create a bundle using the JSON assistant.
    This bundle contains the required mapping artifacts for data transformation.
  2. Install the bundle in CICS to make the mappings available.
  3. Create or update an application program to handle data transformation.
    You have two options:
    • Use the TRANSFORM DATATOJSON and TRANSFORM JSONTODATA API commands in the application program. This is the recommended approach.
    • Use the LINK PROGRAM API command to link to CICS-supplied linkable interface DFHJSON.
    The application must use a channel-based interface.
  4. Run the application to test that the transformation works as you intended.

Results

Your application data is transformed into JSON or your JSON is transformed into application data.

What to do next

Steps 1 to 4 are explained in more detail in the following topics.