Raising alerts from udf or java mapping in single stack PI

Hi

We are receiving asynchronous message from 3rd party in sap pi. The message has a field called error type. My requirement is to trigger alert (or alert rule) 'AlertA' if field 'error type' has value 'A' and trigger alert 'AlertB' if field 'error type' has value 'B'. If there is any other value normal processing should happen.

I am thinking of writing code in UDF or java mapping to trigger different alert rules based on message content. Is there are any API that can trigger a particular alert (or alert rule). Is there any other way to address the requirement. We are using single stack java PI 7.40 and we don't intend to use solution manager.

Regards

Sunit