RE: New System Development -- WEB400

> From: Justin Houchin
>
>     We made this same decision about a month ago. We chose CGI because of
> the time frame. I have not programmed in JAVA before and all of
> the articles
> I have read said there is a steep learning curve. We did not have the time
> to learn a new language.

Let me say up front that I am very biased towards servlets and JavaServer
Pages, for a number of reasons, not the least of which is that I sell a
product that makes heavy use of servlet/JSP technology.

That being said, I want to point out that Justin's opinion is one shared by
many people, but that it's not 100% accurate.  Yes, there is a learning
curve to learning Java, and yes you need at least some Java to be able to
use servlets and JSPs.  However, it's not as bad as you might think.

This is because there are really two types of Java programmers: class
creators and class consumers.  Class consumers are more like application
programmers; they use classes created by other people to develop
applications.  Class creators, on the other hand, are more like compiler
developers.  They need to know the very technical details of OO programming
and Java syntax.  However, most well-designed business applications don't
need very much in the way of class creation - most of the classes you will
use have already been created!

If your business logic is written in RPG, the amount of Java you need to
write for your applications is very small.  Basically, your servlets read
data from your application, put that data into beans (think of beans as Java
data structures) and send these beans to the JSP.  The JSP displays the data
to the user.  The user hits a button.  The servlet then reads the data from
the user and passes it back to an RPG program.  There is very little code
involved.

I give labs on this at COMMON and at iSeries DevCon, and somebody with just
a little Java knowledge can usually create a successful servlet/JSP
combination in an hour or two.  I also teach onsite seminars, where RPG
programmers with zero Java knowledge learn Visual Age for Java, basic Java
syntax, servlets, JSPs and AS/400 communications.  Most programmers learn
how to create a fully functional business application in a week.

The beauty of this approach is, as David pointed out, if your business logic
changes, your RPG programmers take care of it, and if your UI needs change,
your JSP programmers take care of it, and they can often work independently.
With CGI, your RPG programmers need to know a bit more about the interface,
unless you use a tool like CGIDEV.  And once you do that, you're stuck with
whatever functionality is supported by the tool.

With the servlet/JSP approach, your JSP programmer can use any of the most
advanced features of HTML without having to worry about whether the RPG
business logic is affected.

Joe