with announcement Deprecated features in the 3.8.0 IBM WebSphere DataPower SOA Appliances products the coprocessor features (with xa.jar) has been deprecated.
It is still part of even 3.8.2.x firmware though.
Coprocessor mode allows for transparent execution of XSLT transformations on DataPower in Java environments by xa.jar.
In short the stylesheet and xmlfile are sent to DataPower appliance, the stylesheet gets compiled if not already in stylesheet cache,
is then applied to the xmlfile as input and returns the response generated by DataPower to the Java application.
While this is useful for processing it definitely is also useful for development and testing of stylesheets without always having to upload the stylesheets to the appliance explicitely.
(as you know processing of stylesheets making use of DataPower extension functions is not possible by other XSLT processors)
The recommended alternative from deprecation announcement was "Use HTTP loopback".
Find attached DataPower service coproc2.zip, it does allow for
- processing of received xmlfile by received stylesheet on DataPower appliance
- because it is a MPGW it also may be used on XB60 and XM70 models which never provided coproc support.
The service export was generated with firmware 22.214.171.124.
I successfully imported it on 3.8.0, 3.8.1 and 3.8.2 boxes.