title: How to debug grails runtime exception?
body: <p>I have a grails project and a java project. The java project was a standalone set of POJO classes, and I just dumped them into src/java under my grails project.</p>
  
  <p>In the controller, I added an import statement for this package.</p>
  
  <p>Now when I do a grails run-app and try to run the program, I get a grails runtime exception. It is saying NoClassDefFound for a class that is in a package that one of my POJOs imports.</p>
  
  <p>The error message is showing on a line of my Controller, but the class that is missing is from an external jar that my POJO needed. I moved the .jar that it is complaining about to the grails project's lib folder. What else do I need to do?</p>
  
  <p>How do I track down what is really causing this problem?</p>
  
  <p>Thanks!</p>