title: Programatically add class to existing JAR file
body: <p>I get path to .jar file as user input of my java application. I need to add one class that is on my class path to that .jar file and then send the .jar file to external service (over network). The service on the other site must be able t load classes from the .jar file including the one I added in my application. </p>
  
  <p>The solution should have these properties:</p>
  
  <ul>
  <li>universal: should work for any thinkable .jar containing classes user can give me. </li>
  <li>automatic: class addition must by done by my java application.</li>
  </ul>
  
  <p>The class to be added to .jar file has name that does not collide with any other class in that JAR. </p>