RE: Java versus RPG on iSeries

["Joe Pluta" <joepluta@xxxxxxxxxxxxxxxxx>]

> From: Chris Hanisch
>
> I am investigating the possibilities of creating Java applications on the
> iSeries and replacing some of the RPG applications.  I was wondering if
> anyone else has had experience in replacing RPG with Java on their iSeries
> and what some of the advantages and disadvantages are.

Chris, I've been using Java for a long time now, and it is my firm opinion
that Java is not the right tool for business application development.  RPG
is still the best language for any non-trivial business applications,
because of its direct integration with OS/400 and DB2/400.  Java adds a
level of indirection both in its program architecture (via the JVM) and its
database access (which I assume will be JDBC in your case).

> 1) Run Time/Performance.  Can Java be just as quick as sensible to use for
> Interactive and Batch Programming ?

No.

> 2) Is it sensible to still use Green Screen with Java and slowly convert
> over to GUI interfaces ?

No.

> We are in need of developing a green screen
> application using Java to show that Java can do the exact same
> thing as RPG.
> Anybody know how easily this can be done or provide some sample code ?

No.

> 3) Are the advantages significant enough to warrant migration to
> Java on the
> iSeries ?

No.

> If anyone has some information/experience on dealing with this,
> it would be
> greatly appreciated.

As I said, I've done a lot of Java programming for the iSeries.  I've
written and taught extensively on the topic, and I believe that Java (and to
a lesser degree OOP programming in general) is best suited to highly
definable problem sets, such as middleware, and less suited to complex,
changing requirements such as those found in business applications.

I have seen very few successful business application implementation on any
platform, much less the iSeries, which already has not one but two built-in
business languages, COBOL and RPG.

Joe