Maximizar un jFrame

Este código permite maximizar un jFrame

import javax.swing.JFrame;
import javax.swing.JPanel;
import java.awt.BorderLayout;
import javax.swing.JLabel;

public class Maximixado {
private JFrame jFrame = null;
private JPanel jContentPane = null;
private JPanel jPanel = null;
private JLabel jLabel = null;

public Maximixado() {
}

public JFrame getJFrame() {
if (jFrame == null) {
jFrame = new JFrame();
jFrame.setSize(new java.awt.Dimension(400,200));
jFrame.setExtendedState(JFrame.MAXIMIZED_BOTH);
jFrame.setTitle("jFrame centrado en la pantalla");
jFrame.setResizable(false);
jFrame.setContentPane(getJContentPane());
}
return jFrame;
}

private JPanel getJContentPane() {
if (jContentPane == null) {
jContentPane = new JPanel();
jContentPane.setLayout(new BorderLayout());
jContentPane.add(getJPanel(), java.awt.BorderLayout.CENTER);
}
return jContentPane;
}

private JPanel getJPanel() {
if (jPanel == null) {
jLabel = new JLabel();
jLabel.setBounds(new java.awt.Rectangle(10,10,200,36));
jLabel.setText("Este frame está maximixado");
jPanel = new JPanel();
jPanel.setLayout(null);
jPanel.add(jLabel, null);
}
return jPanel;
}

public static void main(String[] args) {
Maximixado maximixado = new Maximixado();
maximixado.getJFrame().setVisible(true);
}
}