Running Java program on iSeries on command line

Question

I've created a java program and I'm wanting to run it from the iSeries. I've been able to get it to run from the QSH so I know it compiled and runs fine, but I need to run it from the command line not QSH. The program requires the jsch-0.1.55.jar file for the program to work correctly and I'm not 100% sure how to to call the jar file with the program its referencing to.

I've tried

RUNJVA CLASS(ANL0106J) CLASSPATH('/JAVA/Jars/jsch-0.1.55.jar')

That didn't work. Then I tried

RUNJVA CLASS('/JAVA/Jars.jsch-0.1.55.jar':. ANL0106J) CLASSPATH('/Java/Jars/jsch-0.1.55.jar')

That didn't work either. What am I doing wrong?

Answer 1

Having successfully done this many many times, your last try seems pretty close, but change the CLASS parameter to point to your class file which contains the main method. ANL0106J seems like a pretty weird class name.. Example would be:

CLASS(com.company.test.ApplicationMain)

With the CLASSPATH pointing to the required jars using the full path names. For example:

RUNJVA CLASS(com.company.test.ApplicationMain) CLASSPATH('/test/app.jar:/test/dependency.jar')

To make matters a bit easier, you could even include your dependency in your JAR file by using something like maven or Gradle to create your builds, which can then be configured to generate fat jars. Essentially, those are jars that contain the other JAR files that your application depends on. That way, you can also be pretty sure that your application will continue to work, even after you update a single jar file on your ibm i machine for example. Shadowjar for example is pretty easy to setup using a gradle project which will do this for you. Then it's just a matter of running the bootjar gradle task and using the RUNJVA command, simply pointing to your single JAR. Don't get caught up in dependency management hell, please. Save yourself and future devs by using something like maven or gradle. Gradle/maven can even be used to manage depencencies using a maven repository with a tool such as Sonatype Nexus which can also be hosted locally. If your JAR has a valid manifest, you don't have to do anything else. It would look like this:

RUNJVA CLASS('/test/app.jar')

Especially useful for using CI, which can build the JAR for you from a GIT repository and place the fat jar in the correct path, with you not having to do a single thing. Setting up Jenkins on an as400 isn't that difficult at all using the apache WebSphere application server which is an option that can be used to host WAR files, to put it simply (it can do a lot more than that though :P).

Hell, using only a single jar for the RUNJVA command should also speed up the time it takes to start your application since it only needs to verify a single jar. Just food for thought. Here's the maven entry by the way: https://mvnrepository.com/artifact/com.jcraft/jsch/0.1.55

On a side note for java/react devs: Yes, fellow Java/react developers, one could use the RUNJVA command to modernize ibm i development to run Spring boot applications! We are successfully running react front end applications using a spring boot backend system, Works extremely fast, as expected :)

(Same answer given to you on Reddit, simply on this platform to make it visible for others that are looking for this on Stackoverflow)