import java.awt.FlowLayout; import javax.swing.JButton; import javax.swing.JFrame; public class SecondGUI extends JFrame { public static void main(String[] args){ new SecondGUI(); } public SecondGUI(){ super("SecondGUI"); JButton jb = new JButton("Button"); getContentPane().setLayout(new FlowLayout()); getContentPane().add(jb); // getContentPane().add(jb, BorderLayout.CENTER); setSize(300,200); setVisible(true); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } }