help with running clojure, possible classpath issue

Question

admin@apollo:~/clojure$ clojure
Clojure 1.0.0-
user=> (require 'clojure.contrib.str-utils)
java.io.FileNotFoundException: Could not locate clojure/contrib/str_utils__init.class or clojure/contrib/str_utils.clj on classpath:  (NO_SOURCE_FILE:0)
user=> 

What have I done wrong while installing clojure? Why cant clojure locate my java classes? I have java installed.

admin@apollo:~/clojure$ sudo apt-get install sun-java6-jre sun-java6-jdk
sudo: unable to resolve host apollo
Reading package lists... Done
Building dependency tree       
Reading state information... Done
sun-java6-jre is already the newest version.
sun-java6-jdk is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 15 not upgraded.


admin@apollo:~/clojure$ java -version
    java version "1.6.0_20"
    Java(TM) SE Runtime Environment (build 1.6.0_20-b02)
    Java HotSpot(TM) 64-Bit Server VM (build 16.3-b01, mixed mode)
    admin@apollo:~/clojure$ 

please help! thanks!

Answer 1

str utils is something that comes with clojure-contrib. It's not a standard java lib. So, simply installing java wont help. When you start clojure make sure the clojure-contrib jar is mentioned in the classpath. You can get the latest(1.2) clojure and clojure-contrib jar from clojure.org

For e.g. This is how i start the REPL

java -server -cp ~/clojure-1.2.0.jar:~clojure-contrib-1.2.0.jar:. clojure.main --repl

Answer 2

It's great to learn figure this out manually because understanding the classpath makes the world a better place. In practice Many Clojurians use leiningen, maven, or cake.

Personally i would reccomend using leiningen:

• wget http://github.com/technomancy/leiningen/raw/stable/bin/lein
• make this exacutable and save it somewhere like ~/bin or /usr/bin or whatever.
• lein new MY-PROJECT-NAME
• lein deps
• lein repl
• hack away!

There are lots of reasons not to use an automated tool and these things dont fit everyone. For the time it takes to set this up its worth it to me even for simple one-liners.

Answer 3

I use maven to handle all dependencies, and it works a treat.

I wrote a blogpost here: http://learnclojure.blogspot.com/2010/08/clojure-emacs-swank-slime-maven-maven.html about how to set up a working clojure/slime setup from scratch on a new machine. It takes about a minute.

Anyway, if all you want is a running repl, then you can:

Install maven

Get the pom.xml from the blogpost, and put it in a directory.

In that directory run $ mvn clojure:repl

Maven will download everything you need and start a repl, which should be jline-enabled so it's actually usable.

I know this works on Ubuntu, it should work fine on all other linuxes and mac osx. Does anyone know if it works on Windows too?

But if you can use emacs, the combination of clojure/emacs and slime is unbeatable. Do let me know if you have any problems.