Unable to run Java GUI programs with Ubuntu

Question

I am learning GUI in Java, and for that I have created a demo program:

import java.awt.*;

public class FrameDemo extends Frame {

    public FrameDemo(){
           


        

Answer 1

I stopped getting this exception when I installed default-jdk using apt. I'm running Ubuntu 14.04 (Trusty Tahr), and the problem appears to have been the result of having a "headless" Java installed. All I did was:

sudo apt-get install default-jdk