its linux issue, just google it
I was trying to run this java code:
"import java.awt.BorderLayout;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class GUI{
public GUI(){
JFrame frame = new JFrame();
JPanel panel = new JPanel();
panel.setBorder(BorderFactory.createEmptyBorder(30, 30, 10, 30));
panel.setLayout(new GridLayout(0,1));
frame.add(panel, BorderLayout.CENTER);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle("Our GUI");
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args){
new GUI();
}
}"
but then this error appeared:
"java -cp /tmp/AzkXKsnCdS GUI
Exception in thread "main" java.awt.HeadlessException:
No X11 DISPLAY variable was set, but this program performed an operation which requires it.
at java.desktop/java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:208)
at java.desktop/java.awt.Window.<init>(Window.java:548)
at java.desktop/java.awt.Frame.<init>(Frame.java:423)
at java.desktop/java.awt.Frame.<init>(Frame.java:388)
at java.desktop/javax.swing.JFrame.<init>(JFrame.java:180)
at GUI.<init>(GUI.java:12)
at GUI.main(GUI.java:25)"
I am just a beginner in programming and I dunno how to fix it, can you help me?
