title: Running a Scala app as a Java app
body: <p>I'm trying to run the following rocket launching application:</p>
  
  <pre><code>object HelloWorld {
      def main(args: Array[String]) {
          println("Hello World!")
      }
  }
  </code></pre>
  
  <p>directly from java like this:</p>
  
  <pre><code>java -cp scala-library.jar HelloWorld
  </code></pre>
  
  <p>(obviously after compliling with scala)</p>
  
  <p>but get the following error:</p>
  
  <pre><code>Exception in thread "main" java.lang.NoClassDefFoundError: HelloWorld
  Caused by: java.lang.ClassNotFoundException: HelloWorld
          at java.net.URLClassLoader$1.run(Unknown Source)
  (...)
  Could not find the main class: HelloWorld.  Program will exit.
  </code></pre>
  
  <p>Have I overseen anything trivial that I need to do to make it work?</p>