import javax.swing.*; import java.awt.*; public class Main { public static void main(String[] args) { SwingUtilities.invokeLater(() -> { JFrame frame = new JFrame("Login"); frame.setContentPane(new ventana1().panel); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); Dimension pantalla = Toolkit.getDefaultToolkit().getScreenSize(); int height = pantalla.height; int width = pantalla.width; frame.setSize(width/2, height/2); frame.setLocationRelativeTo(null); frame.pack(); frame.setVisible(true); }); } }