Why use API exits
There are many reasons why you might want to insert code that modifies
the behavior of applications at the level of the queue manager. Each of your
applications has a specific job to do, and its code should do that task as
efficiently as possible. At a higher level, you might want to apply standards
or business processes to a particular queue manager for all the applications that use that queue manager. It is more efficient
to do this above the level of individual applications, and thus without having
to change the code of each application affected.
Here are a few suggestions of areas in which API exits might be useful:
- For security, you can provide authentication,
checking that applications are authorized to access a queue or queue manager.
You can also police use of the API by applications by authenticating the individual
API calls, or even the parameters that they use.
- For flexibility, you can respond to rapid changes
in your business environment without changing the applications that rely on
the data in that environment. You could, for example, have API exits that
respond to changes in interest rates, currency exchange rates, or the price
of components in a manufacturing environment.
- For monitoring use of a queue or queue manager,
you can trace the flow of applications and messages, log errors in the API
calls, set up audit trails for accounting purposes, or collect usage statistics
for planning purposes.