RE: Java to AS/400 -- MIDRANGE-L

Hello Marie,

Perhaps I was not clear.  You *cannot* directly call Java from RPG.  The 
closest you can do is to invoke the 
RUNJVA command via QCMDEXC in the RPG program.  (Or a CL program which invokes 
the RUNJVA command).  Better 
yet, submit the RUNJVA command to batch to avoid the DSM and *DTAQ overhead -- 
assuming the Java program 
does not require screen output.  

Either mechanism will result in the Java program running *on* the AS/400 but in 
a separate process (a BCI 
job running a limited instance of QSHELL, the JVM, and your Java program).

You can pass parameters *into* the Java program on the RUNJVA command but you 
cannot pass them back to RPG.  
To have two-way communication requires an external object even when RPG and 
Java are running on the same 
AS/400 system.

Think of it just like using an interactive RPG program to submit a second 
program to batch.  You can pass 
parameters to the batch program via the CALL command or the LDA (yuck) but the 
batch program cannot pass 
parameter values back to the interactive job.

If you invoke the Java program via RUNJVA any required environment variables 
can be set by using ADDENVVAR 
or specifying them on the RUNJVA command.  If you submit the RUNJVA command and 
want environment values from 
the submitting job to be active in the submitted job you will need to specify 
CPYENVVAR(*YES) on the SBMJOB 
command.

Regards,
Simon Coulter.

//----------------------------------------------------------
// FlyByNight Software         AS/400 Technical Specialists
// Phone: +61 3 9419 0175      Mobile: +61 0411 091 400
// Fax:   +61 3 9419 0175      E-mail: shc@flybynight.com.au
// 
// Windoze should not be open at Warp speed.
 

//--- forwarded letter -------------------------------------------------------
> X-Mailer: Internet Mail Service (5.5.1960.3)
> Date: Wed, 02 Sep 98 07:51:53 -0500
> From: "Graziano, Marie" <mgraziano@badgermeter.com>
> To: "'MIDRANGE-L@midrange.com'" <MIDRANGE-L@midrange.com>
> Reply-To: MIDRANGE-L@midrange.com
> Subject: RE: Java to AS/400

> 
> Thanks for the response.  Yes we are using DTAQ for the communication
> between a java pc program and rpg.  What I was looking for is someone
> who has created a java program and it is running on the AS/400  and a
> RPG or CL is calling it.  
> 
> Marie Graziano
> Mgraziano@badgermeter.com
> 
> 
>               -----Original Message-----
>               From:   Simon Coulter [mailto:shc@flybynight.com.au]
>               Sent:   Tuesday, September 01, 1998 9:47 PM
>               To:     MIDRANGE-L@midrange.com
>               Subject:        Re: Java to AS/400
> 
>               Hello Marie,
> 
>               What are you trying to accomplish?  You cannot directly
> call Java from RPG.  You can start a Java program 
>               via the RUNJVA (or JAVA) command but the Java program
> runs in a separate process.  You can pass parameters 
>               to Java but not back to RPG.  This is just like running
> commands via QCMDEXC.  If you want 
>               program-to-program communication between RPG and Java
> you need to use sockets or an external object(*DTAQ, 
>               *DTAARA, *FILE, *USRSPC, etc).
> 
>               Regards,
>               Simon Coulter.
> 
>       
> //----------------------------------------------------------
>               // FlyByNight Software         AS/400 Technical
> Specialists
>               // Phone: +61 3 9419 0175      Mobile: +61 0411 091 400
>               // Fax:   +61 3 9419 0175      E-mail:
> shc@flybynight.com.au
>               // 
>               // Windoze should not be open at Warp speed.

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