title: Arranging a package to 'reverse URL notation': cant get the main class to run
body: <p>I arranged my class to reverse URL notation (newb's reaction to a finicky package). I have the <code>sudoku</code> directory in my <code>home</code>. It hold the binary packages for 'Drools Planner' in <code>binaries</code> and my sources. The directory is arranged like</p>
  
  <pre><code>jesvin@Jesvin-Technovia:~/dev/drools/sudoku$ ls src/main/java/in/co/technovia/sudoku/
  App.class  App.java~  helloworld.class  helloworld.java~
  App.java   domain     helloworld.java   solution
  </code></pre>
  
  <p>My classpath points to <code>.</code> and the above-mentioned <code>binaries</code> of 'Drools Planner'. </p>
  
  <pre><code>jesvin@Jesvin-Technovia:~/dev/drools/sudoku$ export | grep CLASSPATH
  declare -x CLASSPATH=".:/home/jesvin/dev/drools/sudoku/binaries/*"
  </code></pre>
  
  <hr>
  
  <p>The <code>App.java</code> has this in first line: <code>package in.co.technovia.sudoku;</code></p>
  
  <p>I tried to run the <code>App</code> class in the root of my source using the fully qualified package name:</p>
  
  <pre><code>jesvin@Jesvin-Technovia:~/dev/drools/sudoku$ java in.co.technovia.sudoku.helloworld
  Exception in thread "main" java.lang.NoClassDefFoundError: in/co/technovia/sudoku/helloworld
  Caused by: java.lang.ClassNotFoundException: in.co.technovia.sudoku.helloworld
      at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
      at java.security.AccessController.doPrivileged(Native Method)
      at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
      at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
  Could not find the main class: in.co.technovia.sudoku.helloworld. Program will exit.
  </code></pre>
  
  <hr>
  
  <p>My question is kinda elementary to Java: how do I run the <code>java</code> command or set the <code>CLASS_PATH</code> so that the package runs fine?</p>