Smooth the Java Journey with Struts

April 21, 2004 David Morris

Building enterprise-level Web applications is no easy task. There are many ways to present data, control application flow, model data, and organize applications. Fortunately, aspiring Web architects can use tried- and-proven design patterns to avoid the pitfalls of others. The most important design pattern for Web architects is called Model-View-Controller. The MVC design pattern separates applications into three types of components. Model components support data retrieval from a database or other source. View components support the way data is presented to the user or the view. And controller components control the flow of the application.

The main reason to use

Programming with Assertions

April 21, 2004 Cletus the Codeslinger

I am amazed to see how much programmers take for granted. For example, I have worked on many programs in which the author had assumed that an RPG CHAIN operation (a random read) would always find the sought-for record. Occasionally I have to fix a program that ended abnormally because it attempted to divide by zero. The authors of such programs assumed that the divisor would never be zero, but somehow such a thing happened.

To help deal with the problem of assumptions, I have been using assertions in my code. An assertion is a program statement that tests an

Make a CL Program or Module Retrieve Its Name

April 21, 2004 Hey, Ted

As if I didn’t have enough to do, I wasted an hour on a wild goose chase. A user contacted me when a program cancelled. The message she received told her that program XYZ had ended abnormally. It took me a while to determine that program ABC had cancelled instead. It turned out that ABC was a clone of XYZ and still included the following, misleading CL command.

SNDPGMMSG  MSGID(CPF9898) MSGF(QCPFMSG) MSGDTA('Program +
              XYZ ended abnormally') MSGTYPE(*ESCAPE)     

I would like to make CL programs determine their own names, so that I can make sure each program reports the correct name

Admin Alert: When Management Central Server Won’t Start

April 21, 2004 Joe Hertvik

In 2002, I wrote an article on how to troubleshoot IBM’s OS/400 V5R1 Management Central GUI when it simply refuses to start. The Management Central GUI is used for a number of valuable OS/400 functions, including graphing performance data, running commands on other systems, and synchronizing PTFs between iSeries boxes.

The problem is that the Management Central GUI can be fussy, and there are a number of parameters that need to be correctly set in order to make it run. As I explained in my earlier article, these issues include having an enabled QSECOFR user profile and defining your iSeries

OS/400 Alert: Microsoft Extends the Life of JVM

April 21, 2004 Shannon O'Donnell

It really is true that the more things change, the more they stay the same. Just when you were getting used to the idea that Microsoft would be suddenly and precipitously dropping its JVM in September, Microsoft announces that it’s extending the JVM for another three years. Get out your score cards, folks! Also in this issue, we’ll point you to a cool new tool that lets you test multiple operation systems on a single PC.

THE MICROSOFT-SUN YO-YO

Not long ago, Microsoft announced that it would end support of the Microsoft Java Virtual Machine in September. This was, of