Java re-using RPG

["Buck Calabro" <buck.calabro@xxxxxxxxxxxx>]

> This list serves two purposes: it identifies which
> tasks on the iSeries are appropriate for Java and it
> identifies how to make Java components work with
> other iSeries components.

As long as we're discussing philosophy, is the server/client approach
the only one people are using to re-use existing RPG code?  I have an
extremely large application written in Synon.  Synon creates
'functions' written in our case in RPG and compiled as programs.
Virtually all of the business logic resides in these functions; for
example, bump a customer telephone service order to the next status.

Moving to the web, we can create servlets that can call stored
procedures via JDBC that in turn run these external functions.  We can
call them directly with the toolbox.  We can wrapper them in a data
queue server and have the servlets use data queues to communicate back
and forth.  We can wrapper them in a socket listener and have the
servlets use sockets.  We can re-write that logic in Java and use JDBC
to grab the database records.  The list goes on, I'm sure.

Since we've been discussing benchmarks and performance, has anyone
done any testing on the various scenarios I mentioned (and more?) to
see where they fall in the scalability arena?  How about debugging
(like: the web application has been running for a year and then you
get a phone call 'it's down!')  What about adding new web
functionality?  What about maintaining the RPG code (and possible
impacts on the Java side - how do you know that program X is used by
Java?)

There are a lot of interesting questions revolving around the idea of
integrating a Java/web front end with existing RPG code, especially
considering that most shops do NOT want to have to change the RPG code
in order to go to the web.

A penny for your thoughts...
  --buck