package chat;import javax.swing.*;import java.awt.*;import java.awt.event.*;import java.awt.image.*;/* the class is for painting background image to a panel *//** * * <p>Title: 背景圖片類</p> * <p>Description: </p> * <p>Copyright: Copyright (c) 2003</p> * <p>Company: </p> * @author not attributable * @version 1.0 */public class ImagePanel extends JPanel {  private String imageFilename = null;  private Image image = null;  private Toolkit toolkit = null;  public ImagePanel() {    super();    toolkit = Toolkit.getDefaultToolkit();  }  public ImagePanel(String filename) {    super();    toolkit = Toolkit.getDefaultToolkit();    setImageFilename(filename);  }  public void setImageFilename(String filename) {    imageFilename = filename;    try {      image = toolkit.createImage(imageFilename);      setPreferredSize(new Dimension(image.getWidth(this), image.getHeight(this)));      repaint();    }    catch (Exception e) {      e.printStackTrace();      imageFilename = null;      image = null;    }  }  public void setImage(Image image) {    this.image = image;    try {      setPreferredSize(new Dimension(this.image.getWidth(this),                                     this.image.getHeight(this)));      repaint();      //System.out.println(image.getHeight(this));    }    catch (Exception e) {      e.printStackTrace();      this.image = null;    }  }  public void clearImage() {    image = null;    repaint();  }  public Dimension getPreferredSize() {    if (image == null)      return new Dimension(0, 0);    else      return new Dimension(image.getWidth(this), image.getHeight(this));  }  protected void paintComponent(Graphics g) {    Insets insets = getInsets();    g.setColor(Color.white);    g.fillRect(0, 0, insets.left + getWidth(), insets.top + getHeight());    super.paintComponent(g);    if (image != null) {      g.drawImage(image, insets.top, insets.left, this);    }  }  public void reloadImage() {    if (imageFilename != null) {      try {        image = toolkit.createImage(imageFilename);        repaint();      }      catch (Exception e) {        imageFilename = null;        image = null;      }    }  }  public static void main(String[] args){    JFrame frame=new JFrame();    ImagePanel imagePanel=new ImagePanel();      Image image = Toolkit.getDefaultToolkit().getImage("one.jpg");      imagePanel.setImage(image);      JButton button=new JButton("ooooooooooooookkkkkkkkkkk");    imagePanel.add(button);    frame.getContentPane().add(imagePanel);    frame.setVisible(true);  }}