title: cannot load a new clojure library
body: <p>I'm trying out clojure on my second day and I don't understand almost anything yet. I am working with the Programming Clojure 2nd ed. and I am stuck with libraries.</p>
  
  <p>I have Leiningen and have the REPL running. The book first tells the reader to run a simple</p>
  
  <pre><code>(require 'clojure.java.io)
  </code></pre>
  
  <p>which works just fine (I get a nil). Then it wants to load a file called introduction.clj by running another simple</p>
  
  <pre><code>(require 'examples.introduction)
  </code></pre>
  
  <p>where I get an error message</p>
  
  <pre><code>FileNotFoundException Could not locate clojure/java/introduction__init.class
  or clojure/java/introduction.clj on classpath:   clojure.lang.RT.load (RT.java:432)
  </code></pre>
  
  <p>I downloaded the introduction.clj file and looked where should I place it. The error and the book says the command will search in my classpath, but I have no idea where or what that is (after 1h of searching and reading I still don't get it, sorry). I ran a few commands and I had many classpaths listed (from which none contain a clojure/java/io.clj).</p>
  
  <p>So I tried another approach - find the io.clj file on my disk and simply copy the file there and run it with a command</p>
  
  <pre><code>(require 'clojure.java.introduction)
  </code></pre>
  
  <p>This doesn't seem to work either. By the way, the io.clj file I found was in "C:\Program Files\clojure\src\clj\clojure\java". I tried running several other .clj files from the java folder as well from the clojure folder, like javadoc.clj or inspector.clj and all seem to work just fine with the above mentioned command. Only the new file doesn't seem to load this way.</p>
  
  <p>Any help appreciated :)</p>