JOptionPane not working?

Hey guys,

I wrote a program that required the use of JOptionPane. The program compiled without an issue. However, when I try to run it, I get these error messages:

Exception in thread "main" java.awt.HeadlessException:
No X11 DISPLAY variable was set, but this program performed an operation which requires it.
at java.awt.GraphicsEnvironment.checkHeadless(Graphic sEnvironment.java:207)
at java.awt.Window.<init>(Window.java:535)
at java.awt.Frame.<init>(Frame.java:420)
at java.awt.Frame.<init>(Frame.java:385)
at javax.swing.SwingUtilities$SharedOwnerFrame.<init> (SwingUtilities.java:1759)
at javax.swing.SwingUtilities.getSharedOwnerFrame(Swi ngUtilities.java:1834)
at javax.swing.JOptionPane.getRootFrame(JOptionPane.j ava:1697)
at javax.swing.JOptionPane.showInputDialog(JOptionPan e.java:576)
at javax.swing.JOptionPane.showInputDialog(JOptionPan e.java:525)
at javax.swing.JOptionPane.showInputDialog(JOptionPan e.java:475)
at Project0.main(Project0.java:8)


I worked on a Macintosh using terminal. Is there something that I need to download in order to make them work?

Can you make a small, complete program that compiles, executes and show the problem?

Did you read the API doc for that exception?

Edit: API doc?

It is a small program that I just used just to see if the JOptionPane would work. It compiles. When I run it, it displays what I quoted in my original post

Code :

---

import javax.swing.JOptionPane;
public class Project0
{
    public static void main(String [] args){
        String name="";
        int age=0;
 
        name=JOptionPane.showInputDialog(null, "Please enter your name: ");
        age=Integer.parseInt(JOptionPane.showInputDialog(null, "Please enter your age: "));
 
        JOptionPane.showMessageDialog(null, "Hello" + name + ". You are " + age + "years old!");
    }
}

---

Quote:

---

java.awt.HeadlessException

---

That's a class. It is documented in the Java API doc: Java Platform SE 7

It works on my Windows7 system.

Thanks for the link.

So I have to have this Java Platform on my computer in order for the JOptionPane to work?

You must have a java program to have gotten the error message.

Does this mean anything: No X11 DISPLAY variable was set,

^I have no idea what the message means. :(

Huh... looking at my applications, it seems that Java VisualM came with the Macintosh. Does that mean anything?

I ran it on Eclipse and it worked fine. I guess Terminal doesn't do GUIs?