问题
I have installed the libraries with Maven to the ~/.m2/repository/ directory. I would like to add that path to the default Clojure classpath. I could not find the documentation how to do that.
Any hints?
Cheers!
clj
Clojure 1.4.0
user=> (require '[clojure.java.jmx :as jmx])
FileNotFoundException Could not locate clojure/java/jmx__init.class or clojure/java/jmx.clj on classpath: clojure.lang.RT.load (RT.java:432)
The class path by default is:
user=> (println (seq (.getURLs (java.lang.ClassLoader/getSystemClassLoader))))
(#<URL file:/Users/myuser/cljmx/> #<URL file:/usr/local/Cellar/clojure/1.4.0/clojure-1.4.0.jar> #<URL file:/Users/myuser/cljmx/>)
nil
回答1:
The non-painful, popular method is to not mess with maven and classpaths and the JRE directly and use leiningen: https://github.com/technomancy/leiningen/
Otherwise, you can modify whatever is in clj and add/set the classpath in whatever ways java likes. See for example Setting multiple jars in java classpath
回答2:
Leiningen really makes this process a lot less painful by keeping the setting of the classpath associated with the project, and more importantly leads to a repeatable build process. where you can come back to the project years later and still get a repl. A general outline of using leiningen in these cases:
- lein new projectname
- add the library you need to your project.clj file with a name you choose
- run lein deps to print out the command to use to add the jar to your local repo
- add the jar
- run lein deps again (you can skip this step if using leiningen2)
- run lein repl
- enjoy
this is assuming that the library you are using is not already part of or available from a package in a maven repo, which many are.
回答3:
It should be noted that you also have the option of adding classpaths at runtime with the library pomegranate https://github.com/cemerick/pomegranate
This lets you do like:
(require '[cemerick.pomegranate :as pom])
(pom/add-classpath "/home/user/~.m2/....")
回答4:
I assume that clj is a script to start Clojure REPL. Take a look into this script and find line similar to this:
java -cp /path/to/clojure.jar clojure.main
Here you start class clojure.main having "clojure.jar" on your classpath. To add more jars just add them to the end of -cp option values. E.g. on Linux:
java -cp /path/to/clojure.jar:/path/to/mylib.jar clojure.main
(use ; instead of : on Windows)
However, very soon you'll get tired of this way and will look for project management tool. So it makes sense to start using it right now. Take a look at Leiningen - it manages dependencies for you based on Maven (so it will be extremely easy to add new jar) and has REPL.
来源：https://stackoverflow.com/questions/11973694/how-to-add-directory-to-clojures-classpath