Java sample(Image File IO)

//Example1D
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Example1D extends JFrame implements ActionListener {
  private static final String window_title = "Image File IO";
  private static final String btnOpen_title = "Open";
  private static final String btnSave_title = "Save";
  private static final int window_width = 640;
  private static final int window_height = 400;
  private static final long serialVersionUID = 1L;
  JFileChooser fc = new JFileChooser();
  JButton bt01;
  JButton bt02;
  BufferedImage img = null;
  public static void main(final String ar[]) {
    final JFrame f = new Example1D();
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setSize(Example1D.window_width, Example1D.window_height);
    f.setVisible(true);
  }
  Example1D() {
    super(Example1D.window_title);
    this.bt01 = new JButton(Example1D.btnOpen_title);
    this.bt01.setActionCommand(Example1D.btnOpen_title);
    this.bt01.addActionListener(this);
    this.bt02 = new JButton(Example1D.btnSave_title);
    this.bt02.setActionCommand(Example1D.btnSave_title);
    this.bt02.addActionListener(this);
    final Container c = this.getContentPane();
    final JPanel p1 = new JPanel();
    p1.add(this.bt01);
    p1.add(this.bt02);
    c.add(p1, BorderLayout.NORTH);
  }
  public void actionPerformed(final ActionEvent ae) {
    if (ae.getActionCommand() == Example1D.btnOpen_title) {
      final int fd = this.fc.showOpenDialog(Example1D.this);
      try {
        if (fd == JFileChooser.APPROVE_OPTION) {
          try {
            this.img = ImageIO.read(this.fc.getSelectedFile());
            this.repaint();
          } catch (final Exception e) {
          }
        }
      } catch (final Exception e) {
      }
    } else if (ae.getActionCommand() == Example1D.btnSave_title) {
      final int fd = this.fc.showSaveDialog(Example1D.this);
      try {
        if (fd == JFileChooser.APPROVE_OPTION) {
          try {
            final boolean rc = ImageIO.write(this.img, "jpeg",
                this.fc.getSelectedFile());
            this.repaint();
          } catch (final Exception e) {
          }
        }
      } catch (final Exception e) {
      }
    }
  }
  @Override
  public void update(final Graphics g) {
    this.paint(g);
  }
  @Override
  public void paint(final Graphics g) {
    final Graphics2D g2 = (Graphics2D) g;
    if (this.img == null) {
      g.clearRect(0,0,Example1D.window_width-1, Example1D.window_height-1);
    }else{
      g2.drawImage(this.img, 0, 0, this);
      final Graphics2D g3 = this.img.createGraphics();
      g3.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
          RenderingHints.VALUE_ANTIALIAS_ON);
      Font font = new Font("Arial", Font.PLAIN, 24);
        g3.setFont(font);
      g3.setColor(Color.red);
      g3.drawString("hear", 100, 100);
    }
    if (this.img != null) {
      g2.drawImage(this.img, 0, 0, this);
    }
    bt01.repaint();
    bt02.repaint();
  }
}