Re: Callable statement with RPG

[Dieter.Bender@xxxxxxxxxxx (Dieter Bender)]

Hi Jon,

the problem I see is: marketing guys are telling the rpg guys calling java
methods is cool, the threading issues are solved, if you compile your rpg
with *serialize.
rpg programmers don't know anything about multi-threading and therefor I
never would call any rpg programm or procedure synchronous via jni. I
wouldrecommend to use stored procedures for programs and UDFs for
subprocedures.

Dieter

Am Sonntag, 17. März 2002 21:00 schrieben Sie:
>  >> but you must be careful with threading issues. The rpg must not call
>  >> any
>
> java function that might start another thread.
>
> Agreed but I'm mostly interested in Java calling RPG than the other way
> round.  There are also problems with RPG creating Java object in that you
> have to do your own "garbage collection" as the JVM doesn't know about nay
> object the RPG creates and can't clean them up.
>
> As to examples - Barabara Morris wrote a piece for iSeries Magazine but I
> can't find the article on the web site.  The source code can be found at
> our old companies web site (they haven't cleaned up the pages so they are
> still there) the URL is http://www.e400.com/JonSusan/HansAndBarbaraMay.html
> and click on the "Get source files" link alongside the Java reference.
>
> The RPG manual has a lot of good stuff in it on the subject but the
> examples are not too wonderful.
>
> In essence, all you need to do is add:
>
> EXTPROC(*JAVA:'classname' :'methodname') to the Prototype of the
> subprocedure.  Then you simply add the native method prototype to your Java
> code, and make sure you invoke the System.load method in your class to load
> the service program containing the native method(s).
>
> The only real drawback is that because the compiler does such a lot of work
> on the parms etc. "under the hood" you can't call the same subproc from
> RPG. That means that for any subprocs used by both Java and RPG the Java
> has to use a stub procedure to call the "real" thing.
>
> I have some materials in my V5 presentation that you are welcome to have a
> PDF of if you e-mail me OFF-LIST.
>
> Jon Paris
> Partner400
>
>
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--
mfG

Dieter Bender


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