Re: RPG to Java Conversion

[TitanRebel <TitanRebel@xxxxxxxxxxx>]

Sorry for the delayed response...busy day.

In a nutshell, what we are doing is Servlet/JSP for simple navigation 
and simple applications with less complex UI requirements.  However, the 
bulk of our effort has been using Swing Applets comunicating XML over 
HTTP to Servlet(s), which may or may not be using existing RPG logic to 
return results to the Applet.

A couple of things I didn't point out in the original email were that we 
are enhancing existing functionality of these legacy applications while 
moving parts of them to Java.  We are not just changing the 
"presentation layer".  Removing 5250 Interactive Tax is a benifit, but 
not the driving force.  We (my company) want to place more importance on 
an intuitive, yet robust UI.  We are a software vendor, and compete with 
other solutions based on Windows and also Unix.  UI is considered a 
weakness of our system (yes, this is a perceived weakness).  We might 
have been out of business several years ago, if not for Seagull's JWalk 
product (screen-scraper).  I don't like JWalk very much, but it served 
it's purpose.  It gave a better impression to perspective customers than 
did green-screen.  We have passed the limit of the JWalk product, and 
Java is our next step (albeit large).  Applets give us the advantage of 
a Rich GUI without having to install/deploy/upgrage each and every PC 
that needs to use the software.

Ken Kennedy

Joe Pluta wrote:

> > From: Ken Kennedy
> >
> > My company is going through a transition.  Myself and a few others have
> > shown them (upper management) what Java is capable of doing, and they
> > like it.  We are an ISV, and all of our source is CL or RPG.  We are not
> > looking to move away from the iSeries platform, and we are not looking
> > to replace major business logic already mature and working.  We are
> > wanting to replace the presentation layer with Java/HTML.  We have about
> > 35 RPG developers, and 4 Java developers.
> >
> > My boss wants to review several plans on how we are going to transition
> > RPG developers to Java.  Again, we are not wanting to transition all 35
> > to Java.  Do any of you know of any literature (white papers, documents,
> > web sites, etc...) available that outlines this type of transition?  Any
> > success stories?  Any literature would be appreciated.
> >    
>
> Since I sell a product that does exactly this (replace the user interface of
> legacy systems with Java/JSP), I am intrigued as to how you plan to
> implement your design.  My book on the subject, E-Deployment: The Fastest
> Path to the Web, is still available, and gives an excellent review of the
> steps required to peel off the 5250 interface and replace it with JavaServer
> Pages.  I cal this the server/client architecture, as opposed to
> client/server.
>
> If that's indeed what you are trying to do, then you don't need a lot of
> Java folks.  Java development is really broken down into two levels: class
> creators and class consumers.  Class creators are the folks who write the
> hard bits, the plumbing, if you will.  The class consumers then simply call
> APIs.
>
> In your environment, you'd need someone to write the interface between the
> RPG and the web server, and then you'd need some JSP experts to help you
> design the user interface.  In the perfect world, your RPG programmers would
> never need to know anything about Java, at least in the beginning, because
> they would continue to maintain your applications using traditional green
> screen techniques.  A second step would then modify these programs to use
> APIs to talk to the web server.
>
> Eventually, you would encapsulate your business logic in true servers that
> could be invoked directly by servlets in a client/server architecture (at
> which point you would then have a staff consisting of servlet designers who
> know Java and business logic designers who know RPG, along with JSP
> designers who do the UI portion), but in the meantime the server/client
> model would get you to market almost immediately.
>
> Joe
>
>
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