Java AWT Graphics2D measure String

import java.awt.Color;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.font.FontRenderContext;
import java.awt.geom.Rectangle2D;
import java.util.Random;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class Main extends JPanel {
  Random rnd = new Random();

  @Override/*  ww  w  .  ja  va 2  s.  c o m*/
  public void paintComponent(Graphics g) {
    super.paintComponent(g);

    Graphics2D g2d = (Graphics2D) g;
    g2d.setBackground(Color.WHITE);
    g2d.clearRect(0, 0, getParent().getWidth(), getParent().getHeight());
    // antialising
    g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

    // SanSerif
    g2d.setPaint(Color.BLUE);
    Font serif = new Font(Font.SERIF, Font.PLAIN, 30);
    g2d.setFont(serif);

    String sentence1 = "The quick brown fox jumped";
    String sentence2 = "over the lazy dog.";

    FontRenderContext fontRenderCtx = g2d.getFontRenderContext();
    Rectangle2D bounds1 = serif.getStringBounds(sentence1, fontRenderCtx);
    Rectangle2D bounds2 = serif.getStringBounds(sentence2, fontRenderCtx);

    int y = 50;
    int x = 0;
    FontMetrics fm = g2d.getFontMetrics();
    int spaceRow = fm.getDescent() + fm.getLeading() + fm.getAscent();

    x = (getParent().getWidth() - (int) bounds1.getWidth()) / 2;
    g2d.drawString(sentence1, x, y);
    x = (getParent().getWidth() - (int) bounds2.getWidth()) / 2;
    g2d.drawString(sentence2, x, y + spaceRow);
  }

  public static void main(String[] args) {
    // create frame for Main
    JFrame frame = new JFrame("java2s.com");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    Main Main = new Main();
    frame.add(Main);
    frame.setSize(300, 210);
    frame.setVisible(true);
  }
}