Re: RPG Web Service Program

Steve, I had a similar problem with PHP calling a service program that had
java calls.

While I did not solve the cause of that I finally looked more closely at
my design and realised that I could end up with many JVM's running based
on the number of users accessing the web page.

What I did was to move the java calls to a separate program and used data
queue's to send the request and receive the reply. Now I have a single
(monitor) JVM processing the requests and performance was fine. I can
also scale this by starting a second or more monitors to process the
requests on the data queue.

Your application design may be totally different and the problem I had may
not exist but your question just reminded me of the issue I had and how I
resolved it.

Cheers

Don



From: "Steve M via RPG400-L" <rpg400-l@xxxxxxxxxxxxxxxxxx>
To: "'RPG programming on IBM i'" <rpg400-l@xxxxxxxxxxxxxxxxxx>
Cc: "Steve M" <txpenguin1@xxxxxxxxxxx>
Date: 16/04/2020 06:22 AM
Subject: RPG Web Service Program
Sent by: "RPG400-L" <rpg400-l-bounces@xxxxxxxxxxxxxxxxxx>



All,

I write RPG (and SQLRPGLE) programs all of the time that I then attach to
be used as Web Services. No issues there.

However, I now have a need for the web service program to call a Java
process. When I compile the program as a "regular" program I receive no
errors. However, when I change the Ctl-Opt to read
PgmInfo(*PCML:*Module), as I do for all of my other web service's
programs, I receive a RNF0302, Errors were found while generating the
program information to be placed in the module.

That's the entire extent of the information. No more. Unlike my previous
RPG service programs that were "pure RPG", this does have prototypes for
the Java, Java class declarations, creation of Java objects, and such, but
that is all needed for RPG to make the call to the Java class.

Has anyone successfully created an RPG program, as a web service, where
that web service then directly calls a Java class in the IFS? This must
be possible, right? I feel like I am missing something very obvious
inside of my RPG program but can't figure out what.

Any and all thoughts and ideas, as always, are very welcomed. I really
don't want to have to add another layer: an RPG program as a web service,
calling another RPG program that call the Java process - that seems really
silly, but at this point it also seems like the only possible way to
succeed in this process.

Hope that everyone is staying safe and healthy.

Thanks,

Steve Meisinger