Can't run java program with GUI

Question

My computer can run java program properly.
However, for those program with GUI (using swing),
my computer is unable to display the GUI.
What's wrong with it? Is there any PATH I need to set before running GUI program?
Thanks
icedgold

Answer 1

Cut, copy, paste then compile and run this;-import java.awt.*;
import javax.swing.*;
public class MyJFrame extends JFrame {
  public MyJFrame() {
      super("My first JFrame");
      Container c  = getContentPane();
      JPanel panel = new JPanel();
      panel.setBackground(Color.white);//  (new Color(255, 255, 255));
      JLabel jl = new JLabel("Yes it works");
      panel.add(jl);     
      c.add(panel);
  public static void main(String[] args) {
    MyJFrame frame = new MyJFrame();
    frame.setSize(180,120);
    frame.setLocation(200, 300);
    frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
    frame.setVisible(true);
}