Draw a string in the center of a window in Java

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
//www  . j a v  a2  s  .co m
import javax.swing.JComponent;
import javax.swing.JFrame;

class MyCanvas extends JComponent {
  public void paint(Graphics g) {
    Dimension d = this.getSize();
    Font f = new Font("SansSerif", Font.BOLD, 18);

    g.setColor(Color.black);
    g.setFont(f);
    drawCenteredString("java2s.com", d.width, d.height, g);
  }

  public void drawCenteredString(String s, int w, int h, Graphics g) {
    FontMetrics fm = g.getFontMetrics();
    int x = (w - fm.stringWidth(s)) / 2;
    int y = (fm.getAscent() + (h - (fm.getAscent() + fm.getDescent())) / 2);
    g.drawString(s, x, y);
  }
}

public class Main {
  public static void main(String[] a) {
    JFrame window = new JFrame();
    window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    window.setBounds(30, 30, 450, 450);
    window.getContentPane().add(new MyCanvas());
    window.setVisible(true);
  }
}