title: NoClassDefFoundError running a .jar on linux
body: <p>I'm having issue running a .jar I made on windows on ubuntu.
  I'm not really a linux user and I prefer to build my code from windows eclipse and then I make my tests on linux.
  When I execute my jar in linux I get the following exception generated by a missing .jar reference (I've used gson library class to convert some string to json).</p>
  
  <pre><code>Exception in thread "main" java.lang.NoClassDefFoundError: com/google/gson/Gson ...
  Caused by: java.lang.ClassNotFoundException: com.google.gson.Gson
  </code></pre>
  
  <p>Now, after some researches online I found out where is the classpath directory and I copied the gson.jar into that folder, anyway I still get the error and I'm quite confused about all the classpath thing at this point.</p>
  
  <p>Can somebody help me out?</p>