import javax.swing.*;
public class MainFrame {
public static void main(String[] args) {
JFrame f = new JFrame("Sample");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
addPanels(f);
f.setBounds(100, 100, 200, 100);
f.setVisible(true);
}
private static void addPanels(JFrame f) {
f.setLayout(null);
JButton btn = new JButton("Button");
btn.setBounds(10, 10, 150, 15);
f.add(btn);
JPanel pan = new JPanel();
pan.setBorder(BorderFactory.createLineBorder(java.awt.Color.green, 5));
pan.setBounds(10, 30, 100, 30);
f.add(pan);
}
}