title: What path to write in java -classpath?
body: <p>I have a package with many files and directories (Californium, a CoAP protocol implementation). It comes as a Maven project. I have gone to the directory of the pom.xml file and ran <code>mvn package</code> in the terminal. Everything went fine. But upon going to one of the examples (Helloworldserver.class), and trying to run it with <code>java HelloWorldServer</code> I get:</p>
  
  <p><code>Error: Could not find or load main class HelloWorldServer</code>. </p>
  
  <p>I look at the classpath by typing <code>echo $CLASSPATH</code> and I get nothing. So I try to set the classpath:</p>
  
  <pre><code>java -classpath org.eclipse.californium.examples
  </code></pre>
  
  <p>Which generates a description of all the possible options available for the java command, and does NOT set the classpath.</p>
  
  <p>I chose the classpath in the above command because in the HelloWorldServer.java, there is the first line:</p>
  
  <pre><code>package org.eclipse.californium.examples;
  </code></pre>
  
  <p>I suspect this is wrong, judging by the output of my command. How is the correct way to specify the path? What do I want to point to?</p>