I recently wrote a comment about JavaMail in the MC Press Online forums. The next day, I was asked to write a TechTip about it, and that is what you are about to read.

Let me point out that I didn't write the JavaMail program suite; James Zhang wrote it back in 2002, and I'm just making you aware of it. My goal is to explain how to install the JavaMail program on your iSeries box and how to use it to send email from within your RPG programs. It surpasses SNDDST in a number of ways:

• It is easy to use.
• It is easy to install.
• It can attach objects from all over the IFS and goes beyond the 8.3 DOS naming standard.
• You do not need to create any system distribution directory entries of any kind.
• You do not need to know anything about Java.

Installing JavaMail on the iSeries IFS

Before we start, you must be able to FTP progams/files to the iSeries. If you have not tried this before, go to Google and enter "iseries ftp" and you should be well on your way.

1. Download and unzip the JavaUtil.zip file. (If you use WinZip, right-click and select "Extract to here" and you'll have it unpacked to /JavaUtil/JavaMail, which is the structure used on the IFS as well.)


2. Find the file called JavaMail.properties and open it in a text editor (Notepad or something like it). In this file, you'll find two lines:
   
   email.hosttype=mail.smtp.host
   email.hostname=xxx.xxx.xxx.xxx
   
   Leave the hosttype as it is. But you have to change the hostname to a mail server of your choice; this can be a mail server name or an IP address. (Note: If you are behind a firewall, you might have to alert your administrator that you will be sending email from your iSeries using the mail server.) When you are done, save the file.
   
3. FTP all the files in the /JavaUtil/JavaMail to your iSeries. If you are using the built-in FTP program in Windows, start by creating the directories on your iSeries by entering the following on a command line:
   md '/JavaUtil' and then md '/JavaUtil/JavaMail'.
   (Note: You must create the directories in mixed case as show. Failure to acknowledge case-sensitivity is one of the most common Java programming errors.)
   Then, FTP all the files to /JavaUtil/JavaMail. When you're done, end the FTP job.
   If you use a "real" FTP program, you should be able to FTP the whole lot in one take.
   
4. Download the JavaMail.savf save file. FTP it to your iSeries and restore it:
   RSTLIB SAVLIB(JAVAMAIL) DEV(*SAVF) SAVF(QGPL/JAVAMAIL).
   We are running V5R3, but I have compiled all the programs with tgtrls(*PRV) so it will run on V5R2 also.
   

You are now ready to start using JavaMail, but first, I would like to draw your attention to the JAVAMAIL RPG program written by Mr. Zhang (in library JavaMail in source file QSOURCE). This program does all the hard work. It sets up everything and calls the Java classes. But because Mr. Zhang added an entry point, you can just use the JAVAMAIL program as a black box that you can call with a set of parameters.

Note: Normally, you have to set up some environment variables, which are like a library list to Java programs. When I first installed the JavaMail program, these environment variables really gave me problems, and I cannot say that you won't have to play around with them on your box. Look in source member JAVAMAIL/QSOURCE/STRMAIL if you encounter any problems. I modified this version of STRMAIL, so if you download the programs from somewhere else, this might vary. In the original program, you have to manually run STRMAIL and CLSMAIL before you can send email. I have added these calls to the JAVAMAIL program using QCMDEXC.

I have also included a small program called SENDMAIL that uses the JAVAMAIL program. This program works like a green-screen mail client (Figure 1).

Figure 1: SENDMAIL works like a green-screen mail client. (Click image to enlarge.)

Add the JavaMail library to your library list and enter CALL SENDMAIL from a command line. The program looks like any other mail client and works just the same.

If you want to make a line break in your text, enter Note: Every time you press Enter, the To mail field will be cleared. This prevents Mr. Woodpecker-Finger from holding down Enter and filling up somebody's mailbox within a few seconds.

I hope that you find this TechTip useful and that you can make it work. If you want to get a little deeper into it, I recommend reading Bob Cancilla's JavaMail article at IGNITe/400.

Jan Jorgensen is a programmer at Electrolux Laundry Systems Denmark, working with stuff like RPG, HTML, JavaScript, and Perl. You can reach him at jan.jorgensen@electrolux.dk.