Different Structure Based on Status Code

Sometimes MF buffers’ structures change by the program scenario. With OpenLegacy, you can define the desired structure with a status code and handle the different structures.

What is the status code?

A status code is an integer that describes a buffer structure with hash, for example, F0 will be presented as 15 and F0F0 as 449.

Example hashes:
F0 - 15
F0F0 - 449
F0F1 - 450
F1F0 - 480
F1F1 - 481
F1 - 16
00 - 31

There are no success or error status codes - the customer can select the expected status code.

Status code indicator:

You can indicate the specific success structure by the following application.yml configurations.

ol.cics.project.[orchestrated-key].status-code

Key	Type	Default Value	Description

Key	Type	Default Value	Description
default-success-value	Int	15	The default value indicates success. Default value represents `F0`
indicators[]	List<StatusCodeIndicator>	Empty list	List of status code indicators
indicators[].offset	Int	0	Offset in the buffer to start read the status code
indicators[].length	Int	1	Number of bytes to read from the offset

Application.yml for example:

ol:
  cics:
    project:
      bla:
        base-url: http://localhost
        port: 9090
        uri-map: /api/echo
        code-page: CP037
        user: 
        password: 
        status-code:
          default-success-value: 15
          indicators:
          - length: 2
            offset: 0

How to handle a different structure?

Currently, we have two cases:

The returned status code matched the default-success-value - no exception is thrown.
The return status code doesn't match the default-success-value - an OperationNotMappedException will be thrown.

The OperationNotMappedException contains the full buffer, the status code bytes, and a message with the status code.

We can handle the OperationNotMappedException with try and catch, in case of more than one known status code we can use a switch case block.

An example use case:

In the following example, we will use a simple echo program that returns the same value as it sent in the response.

For this example I’ll decide that my excepted result is:

{
  "echo" : "0"
}

It means that the byte value is F0 and the status code is 15. This value placed at the first byte on the response buffer and its length is 1 byte.

My status code configuration should be:

 status-code:
          default-success-value: 15
          indicators:
          - length: 1
            offset: 0

If I’ll send “0” in the request I’ll get my excepted response, for every other request I’ll get the following exception:

We can catch this exception and handle the different status codes, for example:

E.g: when echo set to 1, we will get