Problem with JFrame in Java

[Mikael Gustafsson]

I have a problem when i try to compile this program below:

import javax.swing.*;
public class GameWindow {
public static void main(String[] args) {
JFrame mainWindow = new JFrame("test");
mainWindow.setSize(300, 200);
mainWindow.setVisible(true);
}
}

I get this error from eclips 3.2 when i try to run it.

Exception in thread "main" java.awt.AWTError: Cannot load AWT toolkit: gnu.java.awt.peer.gtk.GtkToolkit
at java.awt.Toolkit.getDefaultToolkit(libgcj.so.7)
at java.awt.GraphicsEnvironment.getLocalGraphicsEnvir onment(libgcj.so.7)
at java.awt.Window.<init>(libgcj.so.7)
at java.awt.Frame.<init>(libgcj.so.7)
at javax.swing.JFrame.<init>(libgcj.so.7)
at GameWindow.main(GameWindow.java:8)
Caused by: java.lang.ClassNotFoundException: gnu.java.awt.peer.gtk.GtkToolkit
at java.lang.Class.forName(libgcj.so.7)
at java.lang.Class.forName(libgcj.so.7)
at java.awt.Toolkit.getDefaultToolkit(libgcj.so.7)
...5 more

I have installed sun-java5-bin and Installed the j2re1.4 package. And i have run the command
sudo update-alternatives --config java
and updated this so it is to sun-java5.
But still i have the problem with the JFrame program. I can run hello world program with out problems.

Can anyone help me?

/Mikael Gustafsson

[Max Luebbe]

Yeah - Swing isn't supported by GCJ if I recall.

I forget how to change the JRE in an existing project, but to make sure you're using the sun implementation, start a new java project, under jdk compliance click configure default, and there should be a button to show installed jre's.

It sounds like you got eclipse from the repos which has gcj all over the place as a default.

Let me know if this takes care of it.

[gmclachl]

First of all if you don't have it downlod the Sun Java SDK.

Open up elcipse and go
Window > Preferences

Click on the arrow beside and a sub menu will appear.

Select [B]Installed JREs and then press the Add... button

Another window will open up, give your additional JRE a unique name and browse to the folder where sun-java is kept.

George

[Mikael Gustafsson]

Thanks for all the help!
Your good and straigth forward explaning was superb gmclachi!! Now i can begin with my programming. :D

Once again Thanke you!!

/Mikael Gustafsson