Things never live up to expectations. It always seems that if enough of us buy just one of something based on hype, whoever sold it to us gets to retire comfortably while we try to figure out how to get our money back. Software is no stranger to this trend. Weve all seen overzealous expectations turn to disappointment. For example, hype surrounding Java as the One True Language has been enormous. Reams of paper have been devoted to The Wonders of Java, all of them in future tense, so its no wonder people have their doubts. Write Once, Run Anywhere is becoming as overused as scalable, and it hasnt helped that Java has grown up so rapidly, evolving from a nice Web page enabler to arguably the first true cross-platform open-specification language.
On the AS/400, the problem is magnified by the lack of a true GUI. Consequently, even simple demonstration classes that show Javas strengths arent available. The Wonders of Java are primarily in futures, and you know how we feel about futures.
Well, the hype stops here! This issue of MC provides examples of two working applications that take advantage of Javas strengths in different ways. The first application, the Copy Spool File to Portable Document File (CPYSPLFPDF) command, incorporateswithout modificationJava code written originally for UNIX machines to convert AS/400 spool files to PDF files. The second application, SysStats, provides a graphical interface to basic AS/400 system information through IBMs Java Toolbox for the AS/400. The future is now!
CPYSPLFPDF: Cross-platform Comes of Age
Don came up with an interesting idea. He had recently found a public domain Java package that allowed an application to easily create PDF documents. PDF documents are complex, but this package simplified things considerably. (For more information, see the in-depth coverage of the Splf2Pdf class in Spool File to PDF, PDQ in the June/July issue of AS/400 NetJava Expert.) An important strength of Java is its ability to encapsulate complex programming logic, making it easy to use by other applications, and the logic involved in creating PDF documents was a natural candidate for this kind of encapsulation.
There was only one problem: The package was developed for UNIX machines. However, we realized that it didnt matter. If Java were truly a cross-platform product, we should be able to use the Splf2Pdf class on the AS/400, and that was exactly the case. Don
wrote CPYSPLFPDF (see Figure 1) and the CL program it calls. That CL program invokes a Java application Joe wrote, which uses UNIX Java classes. The result was a simple AS/400 command that converted AS/400 spool files into PDF documents you could then download to your PC (or Macintosh or UNIX workstation) and display or print using Adobe Acrobat Reader (see Figure 2).
The utility is simple. Create a directory in your AS/400 Integrated File System (AS/400 IFS) using the Make Directory (MKDIR) command, or use your home directory. Once youve done that, you can execute CPYSPLFPDF in the same fashion you would use to copy a spool file to a database file (see Figure 1). Enter the spool file name and the target file (use an AS/400 IFS naming convention for the file, such as /home/pluta/Compile.pdf), and the utility copies the last spool file with that name from the current job. You can also specify a different job or spool file number, such as CPYSPLF. Upon completion, you will have a PDF formatted file in your AS/400 IFS that you can FTP or access through AS/400 networking. Thats all there is to it!
Downloading and Installation
You must first make a work directory on the AS/400. We suggest creating a directory named java in your AS/400 IFS. (Future projects can go there as well.) Then, make a subdirectory called splf2pdf by using the following AS/400 commands:
These steps are enough to start. Next, you need to get the software onto the AS/400. Visit www.midrangecomputing.com/anje, click on Downloadable Code, and select Spool File to PDF, PDQ from the June/July 1999 section. The zip file to be downloaded is called 9904spool.zip; it contains the Splf2Pdf.jar file and the CPYSPLFPDF and Spool File to PDF Command Procession Program (SPFLPDFCPP) source files that must be uploaded to the AS/400. Unzip these three files from 9904spool.zip and place them in a temporary directory such as C: emp. Then, use FTP to transfer Splf2Pdf.jar to the java/splf2pdf directory. Note the use of the BIN command, which prevents any translation of the files. If youve performed the transfer correctly, you have the byte code version of the Splf2Pdf.jar file on the AS/400 almost ready to run. Use FTP to copy the CPYSPLFPDF and SPFLPDFCPP source files to an AS/400 source file, and compile them following the syntax shown in the comment section of each source member. Figure 3 shows the FTP command invocations required to send the Splf2Pdf.jar file to the /java AS/400 IFS directory and the command and CL source to a utility library. The final step in the installation process requires you to compile the Java classes of the Splf2Pdf.jar file into a *JVAPGM. Use the following command:
CRTJVAPGM CLSF(/java/splf2pdf/Splf2Pdf.jar) OPTIMIZE(30)
SysStats: A Java GUI for AS/400 System Status
SysStats is a Java GUI application written by Alex Garrison to display status information about one or more AS/400s (see Figure 4). Unlike CPYSPLFPDF, SysStats must run from a graphics-capable machine (your PC). However, for SysStats to work on your PC, it must have Suns Java Development Kit (JDK 1.2 or JDK 1.1.7 and Swing 1.1.1) and IBMs Java Toolbox for the AS/400 (IBM AS/400 Java Toolbox Modification 2 beta) installed. For information on how to download and install Suns JDK and IBMs Java Toolbox, visit www.zappie.net/Java/Javatorium/ installi.htm. To download SysStats, see the sidebar to this article, "SysStats: A Java-based AS/400 Performance Monitor," at www.midrangecomputing.com/mc/99/08. Unzip 9908SysStats.zip to a directory called SysStats. To run SysStats, simply execute the SysStats.bat file. When the application GUI
comes up, use the connection menu to establish communication with any number of AS/400s. (Note that SysStats has been tested on V4R3, V3R7, and V3R2.)
Alex created SysStats not only to be a great tool for managing system resources but also as example code for AS/400 Java programmers. For this reason, 9908SysStats.zip also contains complete Java source for Alexs utility. In the Java source for SysStats, you find these cool coding techniques:
Developing your own layout manager
Managing custom events
Using Javas multithreading techniques safely
Using INI files with IBMs alphaWorks IniFile bean
Using a custom chart JavaBean called SlidingGraph
Using IBMs alphaWorks SNMPProtocol bean
Coding dynamic menus
Converting AS/400 time stamps into Java objects
Title Wave Forecast
Will Java be successful on the AS/400? It already is. Hundreds of software products available for the AS/400 have been developed in Java. Most of these products are system software products such as Internet middleware and Web application servers, but business application software written in Java will soon become widely available for the AS/400. Meanwhile, the growing camp of AS/400 and Java experts will be developing useful utilities like CPYSPLFPDF and SysStats. Whether you like the Java programming language or not, you will be using Java-based software, so why not start now?
Spool File to PDF, PDQ, Joe Pluta, AS/400 NetJava Expert, June/July 1999 Hype surrounding Java as the One True Language has been enormous.
CPYSPLFPDF FILE(SPLFPDFCPP) +
Figure 1: CPYSPLFPDF converts AS/400 spool files into PDF documents.