RE: Java extensions directory vs Excel generation

I assume by "single instance issues", you mean the fact that each job only gets a single JVM, which can't be changed or restarted.

Using Java as your driving language is a viable option, but (for performance reasons) you certainly won't want a ton of RUNJVA from RPG/CL.

"Plus I can call as many Java processes as needed while also switching the JVM in a current job."
Please explain. AFAIK, the one JVM per job is an OS restriction.




-----Original Message-----
From: Richard Schoen [mailto:Richard.Schoen@xxxxxxxxxxxxxxx]
Sent: Monday, January 22, 2018 8:04 AM
To: midrange-l@xxxxxxxxxxxx
Subject: Re: Java extensions directory vs Excel generation

We had an issue at RJS when V7R1 came out where the RPG program we had in a production application that used Java would not resolve the classpath no matter what we tried. Our developer at the time worked with IBM as well on this.

So in the end we moved to straight Java. It's much easier to call Java from CL and let it call RPG as needed than it was to leave our customer stranded because we were left scratching our heads over classpath issues and the need to start a new job to use Java classes.

Plus I can call as many Java processes as needed while also switching the JVM in a current job.

I have also played with RPG several times in conjunction with Java and every time I wanted to make a change I had to end my job and restart before re-loading the JVM.

Also the pain of mapping classes to RPG. Who needs it.

You're better to learn a little Java. It's not that hard.

Regards,

Richard Schoen
Director of Document Management
e. richard.schoen@xxxxxxxxxxxxxxx
p. 952.486.6802
w. helpsystems.com

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message: 4
date: Sat, 20 Jan 2018 01:03:25 +0000
from: Justin Taylor <JUSTIN@xxxxxxxxxxxxx>
subject: Re: Java extensions directory vs Excel generation

"In my case I avoid RPG and Java together like the plague because of the single instance issues."


Can you elaborate? I've used RPG and Java for years, and I don't know what you mean by "single instance issues".

________________________________
From: Richard Schoen <Richard.Schoen@xxxxxxxxxxxxxxx>
Sent: Friday, January 19, 2018 8:34 AM
To: midrange-l@xxxxxxxxxxxx
Subject: Re: Java extensions directory vs Excel generation

What you have recommended closely mirrors what I typically do.

Each utility or app has its own IFS folder contains the class/program and any related JAR files.

Then I set JAVA_HOME for the JVM to use.

In my case I avoid RPG and Java together like the plague because of the single instance issues.

I typically run my classes using QSHELL or an app server if I need it to stay loaded.

The benefit to this is I can alter the JVM and CLASSPATH variables and run two different java utilities in the same job even if they have differenet JVM / Classpath requirements.

Regards,
Richard Schoen
Director of Document Management
e. richard.schoen@xxxxxxxxxxxxxxx
p. 952.486.6802
w. helpsystems.com