title: Running Java GUI apps on Cloud 9
body: <p>I'm trying to run a simple app that just creates a <code>JFrame</code> and displays it through the web IDE Cloud 9. I'm getting two separate errors </p>
  
  <ol>
  <li><p>Exception in thread "main" <code>java.awt.HeadlessException:</code><br>
  No X11 DISPLAY variable was set, but this program performed an operation which requires it. </p>
  
  <p>When this issue is resolved <a href="https://stackoverflow.com/questions/5362512/unable-to-run-java-gui-programs-with-ubuntu">here</a> I then get this error:</p></li>
  <li>Exception in thread "main" <code>java.lang.UnsupportedClassVersionError:</code></li>
  </ol>
  
  <p>Is it possible to run GUI programs through cloud 9? Does anyone know how to update the path variable/java version on cloud 9?</p>