How to set CLASSPATH in Linux to let java find jar file?

Question

Under Linux I am trying to run a jar file as follows:

java -jar plantuml.jar -testdot

while having CLASSPATH set to any of th

Answer 1

The classpath is used to find classes when you refer to them by name. It's essentially a list of paths (directories AND jar/zip files) where the JVM needs to look for classes, or other resources when using methods like ClassLoader.getResourceAsStream().

The value passed to the -jar option on the command line is the file-path to the JAR file.

So, it won't find a jar file if you are only referring to the jar file by name. The JAR file path in the CLASSPATH is supposed to be a path element that 'contains' other resources.

What you need to do here, is either

1. Provide the full path to the jar file when trying to execute the jar
2. Set the classpath to the jar file's path, and run the java command giving the name of the main class you want to execute.