How to build a jar file from clojure source code on Windows XP

Without any tool, you're bound to do some quirky steps manually. Say you have clojure.jar in the current directory, along with a target folder for compilation named classes and a clojure source file in src/awesome.clj with the following code:

(ns awesome)

(defn life-universe-and-everything []
  (println "42"))

In order to compile it you will issue the following commands on the command line:

EDIT: use semicolon instead of colon to separate classpath elements in Windows environments

java -cp clojure.jar;classes;src clojure.main
Clojure 1.3.0
user=> (compile 'awesome)

This will produce the compiled classes into the classes folder. Please note that if your code depends on any library, you need to adapt the -cp parameter values when starting the JVM.

Than, you will create the JAR file using:

jar cvf awesome.jar -C classes .

Finally, to call your function:

java -cp clojure.jar;awesome.jar clojure.main -e "(use 'awesome) (life-universe-and-everything)"

I'd also advise you to read the official documentation.