classpath - How to analyse which jar file is used in a Java program?

Question

Suppose there is a jar file named callme.jar

and it's located in several directories,

how to analyse which one of them is used at run-time?

Answer 1

Invoke the java executable with the -verbose:class argument. This will produce output like:

[Loaded org.apache.log4j.helpers.ThreadLocalMap from file:/C:/.../1.2.14/log4j-1.2.14.jar]
[Loaded org.apache.commons.cli.Option from file:/C:/.../commons-cli-1.2.jar]