Below is an example of adding two panels to a frame. Only one panel (the 2nd, red panel) appears.
![Disappearing Panel In Frame](https://i.stack.imgur.com/jAyjv.png)
Why does the first panel disappear?
import java.awt.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
public class DisappearingPanelInFrame {
DisappearingPanelInFrame() {
JFrame f = new JFrame(this.getClass().getSimpleName());
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f.add(new ColoredPanel(Color.GREEN));
f.add(new ColoredPanel(Color.RED));
f.pack();
f.setVisible(true);
}
public static void main(String[] args) {
Runnable r = new Runnable() {
@Override
public void run() {
new DisappearingPanelInFrame();
}
};
SwingUtilities.invokeLater(r);
}
}
class ColoredPanel extends JPanel {
ColoredPanel(Color color) {
setBackground(color);
setBorder(new EmptyBorder(20, 150, 20, 150));
}
}