You may have already noticed that the New Technology section of Midrange Computing is missing from this issue. It’s missing because it has been replaced with a new section: Cross-platform Development. We replaced the New Technology section for two reasons. One, most of the stuff we’ve been covering in it is now mainstream—it’s no longer new—such as Web serving, HTML, HTTP, and Java. And two, most of the new stuff that’s available for the AS/400 is cross-platform anyway. Technologies and products such as WebSphere, DB2 UDB, Extensible Markup Language (XML), Domino, and Net.Data work on most platforms.

Start with a Little Java

What’s the coverage in MC’s Cross-platform section going to be like? Obviously, a great deal of it will be on the champion of cross-platform technologies—Java. The types of Java articles that are going to be published will be at three levels: Java tutorial, Java utilities, and enterprise Java.

Before you can start development on an enterprise-quality Java application, you need to learn Java. The Java tutorial articles in the Cross-platform section will provide step- by-step lessons on entry-level Java coding techniques. Topics will range from Java Database Connectivity (JDBC) to servlets and JSP basics to the basics of object-oriented design (OOD).

The Java utilities articles will cover the wide variety of Java packages and utilities. For instance, the Cross-platform section certainly will cover the use of IBM’s Java Toolbox for the AS/400. Examples of other subjects that will be considered cross-platform Java utility topics are Java Message Service (JMS), which is an API for queue-based processing, and Java Foundation Classes (JFCs), for GUI development.

The authors of enterprise Java articles will be taking their gloves off. They’ll be hitting heavy will real-world advice and techniques about application design and deployment. The enterprise Java articles will cover such topics as Enterprise JavaBeans (EJBs), advanced servlets and JavaServer Pages (JSPs), and Web application servers.

Add In Web Application Servers

It took years for AS/400 professionals to become comfortable with OS/400’s job environment. Today, most of us are comfortable using commands such as Work with Active Jobs (WRKACTJOB), Open Database File (OPNDBF), and Submit Job

(SBMJOB). But now, we must learn anew because the job environment for Java applications is completely different from the old world of OS/400 jobs. That’s why MC’s Cross-platform section will include articles on Java application design, Java performance tuning, managing enterprise Java applications through WebSphere’s administration client, and the administration facilities of other Web application servers such as BEA Systems’ WebLogic and Bluestone Software’s Sapphire/Web.

Once you learn how to administer cross-platform applications for deployment on the AS/400, you’ll know how to administer Java applications deployed on any operating system, from the AS/400 to Linux to Microsoft Windows NT to Sun Solaris. In future issues, expect interesting articles such as “Running WebSphere with Microsoft’s Internet Information Server (IIS)” and “WebSphere with the Apache Web Server on Linux.”

Top It Off with Other Technologies

It’s sometimes hard for me, the Java guy, to admit that there are cross-platform technologies other than Java. Two other languages, SQL and XML, are both completely cross-platform. Further, both SQL and XML can be used with any programming language. They are both excellent mechanisms for linking data from host-based legacy applications with applications written in any language on any platform. Look for the Cross-platform section to continually include articles on SQL and XML. Obviously, Cross-platform will also cover the Web interface languages HTML, Cascading Style Sheets (CSS), and JavaScript.

Cross-platform will also be covering the old mainstay of cross-platform languages:
C. The C language has long been used to develop applications that can be ported to dissimilar platforms. A case in point is the recently announced AS/400 Portable Application Solutions Environment (AS/400 PASE), which allows UNIX-style C applications to run on the AS/400. Another example of the cross-platform strength of C is the Apache Web server. Apache is written in C and has been successfully ported to numerous platforms, including the AS/400.

The Server Host Rules

The ’60s were the age of the mainframe computer, but, in the ’70s, distributed processing came into vogue. The idea with distributed processing was that companies would have their data processed close to home rather than at corporate centers. Then, in the ’80s, client/server was hot. Tremendous energies were expended on creating applications that processed information on the workstation. But now that the Web has matured, the tide has shifted back to server-side application architectures. Distributed processing was a pain to administer, and client-side applications have, for the most part, failed. So, since server- side is the way to go, what platform should host your applications? Well, if the network is indeed the computer, the host operating system doesn’t matter—it just has to be able to run cross-platform applications well. The key to success is simple: Develop applications using cross-platform strategies and pick the platform that runs your apps best.

Don Denoncourt is a freelance consultant. He can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it..

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MC Press books written by Don Denoncourt available now on the MC Press Bookstore.

		Java Application Strategies for iSeries and AS/400 Explore the realities of using Java to develop real-world OS/400 applications. List Price $89.00 Now On Sale