Java’s Brewing on the AS/400, an Interview with Two IBM Java Segment Managers

Editor’s Note: In the upcoming May 1 issue of MIDRANGE Systems we’re running an in-depth interview with several IBM Java segment managers. As subscribers of the Headline Report e-mail newsletter, you’re getting this exclusive preview.

Java dominates as the programming language of choice for Web-based applications and indeed, its platform independence has completely transformed the way many business applications are both written and used. To learn more about what this all means for AS/400 users, MIDRANGE Systems spoke with IBM’s John Quarantello, AS/400 Java segment manager, and his counterpart on the AS/400 e-business side, Louise Hemond-Wilson.

MRS: Let’s start with the basics. Why is Java so important to the AS/400 community?

JQ: Java is important for application development on the AS/400 for a variety of reasons. Basically, Java provides three main things that the AS/400 needs—a language that can be used to create a graphical user interface, an environment that is designed for Network enablement and portability. With Java, AS/400 customers can extend their existing applications, and/or write new applications.

MRS: Java is certainly recognized for its portability and cross-platform support. In what way does this benefit the AS/400 community specifically, though?

JQ: That’s the thing that we’ve always had problems with—a lot of times applications start out on a Unix machine or an NT machine, or sometimes even a 390, and over the years, we’ve found it very difficult to port those applications to the AS/400. Now, with Java, we’re able to do ports more easily—in a matter of hours in some cases. Java is an ideal environment whether you’re adding new applications to the server, or trying to attract new programmers to the AS/400 platform. I typically joke and say that there are over a million Java programmers today and they’re all AS/400 programmers, they just don’t know it yet.

MRS: To what extent should AS/400 applications be written in Java? When is it appropriate to use Java? To use RPG? In general, does IBM support a migration or an integration strategy?

JQ: It depends. Do you want to use Java on the client, in the middle, or do you want to use Java on the back-end? There are a lot of people who would like to modernize their applications—they could be customers or ISVs that need a better look and feel. For some of them, the concern is to be able to network-enable their application, and they want graphical support. But they’re not worried about portability. For them, products like Jacada or Seagull’s JWalk are basically front-end Java clients that give you the network-enablement and the graphical user interface that people want as a browser as a client, and the back end can remain in RPG or whatever. So that’s one way for people to buy themselves a couple of years of improving an application without touching a line of code at the back end. And that’s a way of extending your applications out to the Web vs. having to rewrite them.

LHW: I think this also extends to the customer in terms of what they can consider as a client that comes to their server for processing it. It’s no longer tied to a PC desktop. You can now have a small Java virtual machine in a ring, and if I wear this ring and I get hit by a car, they can plug my ring in and it has my medical history, my health insurance information, my attorney’s contact information, whatever. We’ve completely exploded what can be considered as a client so we’ve given customers a whole new broad horizon of what they can consider a client, so that's part of it, too.

JQ: Most customers are starting to build applications for the Web that are going to involve transactions, and that’s really where Java plays very, very well because you can build things like shopping cart applications using Java servlets, or applets, or Enterprise Java Beans. And these applications are then portable across the AS/400 as well as other platforms.

MRS: So, does that mean that eventually Java is going to be the right tool to use to build back-end applications?

JQ: Absolutely. … The best way to think of it is if you’re currently an AS/400 programmer, or a customer and you’ve got 100 percent of your applications in RPG, the migration is going to take years to move to Java. And in some cases, it may not even make sense to take an application like a general ledger application and do it in Java. For other people, that are new to the AS/400, they won’t have much interest in RPG, and will be inclined to simply write the applications in the new technology, whether that means Domino or Java or XML.

LHW: Having been a customer that had to write code for a living, I think it’s good that we continue down the path of, “We’re not going to force you to throw everything out and go to something new. We’re there for you as you migrate those applications into the new technologies.” When you do that migration is really dictated by what the customer’s business needs are.

MRS: So, what’s ahead? What can users expect to see in the coming year with respect to Java on the AS/400?

JQ: … you’ll see more support for XML. One of the important capabilities that XML provides is data portability. Java provides application portability—XML is an excellent environment to support data portability. So if somebody has some data in a relational database, some data in a flat-file system, and some in an embedded database, XML gives them the ability to present all different forms of data into one user interface. The really exciting part of XML is that that’s how the AS/400 is going to be communicating to pervasive computing devices—that’s how we’re going to be talking to Palm Pilots, cellular phones, Personal Digital Assistants, rings and so on.

LHW: There will also be derivatives of XML—different versions of XML that are discipline-specific—for instance in the area of trading partner agreements, which will become extremely important in the B2B space.

Related Editorial:

  • Java: Transforming the AS/400?
  • An AS/400 First: Taking the Lead on Java2

    Related Information:

  • DeveloperWorks Java Technology Zone (new window)