Tag: classpath

Trying to use a Java jmod on midrange

I was using functions shipped in a .jmod on z/OS, and could not find how to get use them in Eclipse IDE.

The code was

...
import com.ibm.oti.shared.*; 
...

Building Java code for z/OS on other operating systems told me how to build a jar file from the .jmod

I had to use the right level of Java on midrange. See Getting the right Java installed on Linux. This level had the openj9.sharedclasses.jmod file.

Even though I built the jar file and updated the Java build class path, it could not find the package, getting message “The package com.ibm.oti.shared is not available”.

I found

  • I had to add the .jmod file to the “module” part of the build class path, and not the classpath itself.
  • I had a jar with the same name in the Eclipse application tree.

I fixed these and it worked.

Why can’t Java find my class?

I had specified a classpath to load a class loading program, but my program could not be found.

I specified the Java options -XshowSettings.

The value of java.class.path had just one .jar, and did not include my classpath!

I found in some Oracle documentation

When you use -jar, the specified JAR file is the source of all user classes, and other class path settings are ignored. If you’re using JAR files, then see jar.

Simple – once you know…

How to fix it

I added my class to the Jar

/usr/lpp/javaJ21.0_64/bin/jar uf /u/tmp/zowep/components/gateway/bin/gateway-service.jar -C /u/tmp/java CCLoader.class

My class was found – and it worked!