Should java.classpath combine classpath sources?

Sat, 14 Sep 2019 20:43:46 +0000

"What is my application's classpath?"

It turns out that there is not a straightforward answer to this question.

There are many ways of running Java, each of which may result in different definitions of the application's classpath. The clojure.java.classpath library has, historically, used a variety of heuristics to find and return the Java classpath.

The current approach is a workaround for Java 9, where the default classloader is not an instance of URLClassLoader. This is now causing problems for CIDER users when cider-jack-in injects the JDK source path (see below).

I have been looking at the history of clojure.java.classpath, in particular:

There does not seem to be a single approach that will give the right result in all situations.

Using the system property java.class.path produces incorrect results in an application container environment (CLASSPATH-1).
Getting the classpath from URLClassLoaders does not work in Java 9+ (CLASSPATH-8).
Combining the results would provide more coverage for tools like CIDER and tools.namespace, but would potentially return incorrect results for applications in containers.

I am unsure how to proceed. I am wary of making yet another change to address the most-recent issue, thereby breaking older uses.

Transitive dependency hell

Sun, 04 Aug 2019 16:46:19 +0000

It is impossible to use different versions of the same transitive dependency.
Will it be possible?
Can Java 9 (jigsaw) help?

Clojure Q&A - Recent questions tagged java 9

Should java.classpath combine classpath sources?

Transitive dependency hell