Water mark text field in Java

import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.TexturePaint;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
// w  w w.  j  a  v  a 2s.c o  m
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JTextField;

public class Main {
  public static void main(String[] argv) {
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    
    JTextField textfield = new WatermarkTextField(new File("a.gif"));
    textfield.setText("www.java2s.com");
    frame.getContentPane().add(textfield);
    frame.pack();
    frame.setVisible(true);
  }
}

class WatermarkTextField extends JTextField {
 BufferedImage img;

 TexturePaint texture;

 public WatermarkTextField(File file)  {
   super();
   try {
     img = ImageIO.read(file);
   } catch (IOException e) {
     e.printStackTrace();
   }
   Rectangle rect = new Rectangle(0, 0, img.getWidth(null), img.getHeight(null));
   texture = new TexturePaint(img, rect);
   setOpaque(false);
 }

 public void paintComponent(Graphics g) {
   Graphics2D g2 = (Graphics2D) g;
   g2.setPaint(texture);
   g.fillRect(0, 0, getWidth(), getHeight());
   super.paintComponent(g);
 }
}