设置背景图，并在上面添加可随意拖动的图片标签

最近要通过java的swing组件实现一个功能：添加一张背景图片，之后在上面随意添加不同的可拖动的小图片标签，刚开始不太懂，绕了很大一个弯路，想着用JLayeredPane的分层去实现，但最终没能如愿，从头开始之后，思路一下清晰了起来，想到了一种非常简单的实现方式，这里分享一下代码：
只有一个类，复制粘贴之后，找几张图片，和类放在同一个目录下，在修改一下图片名称，直接运行就能看到效果了：
15362347_201401201738210265.png
package testSwing;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Point;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingConstants;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.io.File;
public class ModuleAdd extends JFrame{
//背景图片
JPanel jpanel;
ImageIcon image;
ImageIcon icon;
Image img;
//
int x, y;//鼠标双击时的坐标
   ImageIcon markerIcon; //标签图标
   //更改标签图片
   private Point pressPoint; //press标签时的鼠标位
   final int PREVIEW_SIZE = 100;  
   JFrame jf = new JFrame("更改标签图片");
   JButton button = new JButton("");
   //以当前路径创建文件选择器  
   JFileChooser chooser = new JFileChooser(".");  
   JLabel accessory = new JLabel();  
   public void changeMarker(){
       chooser.setAccessory(accessory);//为文件选择器指定一个预览图片的附件组件    
       //设置预览图片组件的大小和边框  
       accessory.setPreferredSize(new Dimension(PREVIEW_SIZE, PREVIEW_SIZE));  
       accessory.setBorder(BorderFactory.createEtchedBorder());  
       //用于检测被选择文件的改变事件  
       chooser.addPropertyChangeListener(new PropertyChangeListener()  
       {  
           public void propertyChange(PropertyChangeEvent event)  
           {  
               //JFileChooser的被选文件已经发生了改变  
               if (event.getPropertyName() == JFileChooser.SELECTED_FILE_CHANGED_PROPERTY)  
               {  
                   File f = (File) event.getNewValue(); //获取用户选择的新文件    
                   if (f == null)  
                   {  
                       accessory.setIcon(null);  
                       return;  
                   }  
                   ImageIcon icon = new ImageIcon(f.getPath());  //将所文件读入ImageIcon对象中
                   //如果图像太大，则缩小它  
                   if(icon.getIconWidth() > PREVIEW_SIZE)  
                   {    
                       icon = new ImageIcon(icon.getImage()  
                           .getScaledInstance(PREVIEW_SIZE, -1, Image.SCALE_DEFAULT));  
                   }  
                   //改变accessory Label的图标  
                   accessory.setIcon(icon);  
               }  
           }  
       });  
       button.setToolTipText("选择标签");
       button.setIcon(new ImageIcon(JFrameBackground.class.getResource("/testSwing/Browse-64.png")));
       //为buttom增加事件
       button.addActionListener(new ActionListener()  
       {  
           public void actionPerformed(ActionEvent event)  
           {  
               int result = chooser.showDialog(jf , "打开");  //显示文件对话框  
               //如果用户选择了APPROVE（赞同）按钮，即打开，保存及其等效按钮  
               if(result == JFileChooser.APPROVE_OPTION)  
               {  
                   String name = chooser.getSelectedFile().getPath();  
                   markerIcon=new ImageIcon(name); //显示指定图片  
               }  
           }  
       });
   }
   public void addMarker() {
final JLabel lablel = new JLabel("");
lablel.setHorizontalAlignment(SwingConstants.CENTER);
lablel.setIcon(markerIcon);
lablel.setBounds(x, y, 16, 16);
       jpanel.add(lablel);
       repaint();
       //为添加的标签增加拖动事件
       lablel.addMouseListener(new MouseAdapter(){
@Override
public void mousePressed(MouseEvent e) {
pressPoint = e.getPoint();
}
@Override
public void mouseReleased(MouseEvent e) {
pressPoint = null;
}
       });
       lablel.addMouseMotionListener(new MouseAdapter(){
@Override
public void mouseDragged(MouseEvent e) {
Point nowPoint = e.getPoint();        //当前鼠标拖拽到的鼠标位置
           int diffX = nowPoint.x - pressPoint.x;
           int diffY = nowPoint.y - pressPoint.y;
           /**移动**/
           lablel.setLocation(lablel.getX()+diffX,lablel.getY()+diffY);
               System.out.println(lablel.getX()+"   "+lablel.getY());
}
       });
   }
   public void ini() {
jpanel.addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent m) {
if (m.getClickCount() == 2) {
x = m.getPoint().x;
y = m.getPoint().y;
System.out.println("x:"+x+"  y:"+y);
addMarker();
}
}
});
}
public ModuleAdd(){
setIconImage(Toolkit.getDefaultToolkit().getImage(ModuleAdd.class.getResource("/testSwing/swingTest.jpg")));
icon= new ImageIcon(SwingImgAdd.class.getResource("/testSwing/swingTest.jpg"));
img = icon.getImage();  
jpanel = new JPanel(){
protected void paintComponent(Graphics g) {
g.drawImage(img, 0, 0, icon.getIconWidth(),  
                       icon.getIconHeight(), icon.getImageObserver());
}
};
jpanel.setPreferredSize(new Dimension(icon.getIconWidth(),  
               icon.getIconHeight()));
ini();
changeMarker();
setTitle("增加标签");
button.setBounds(0,20,98,41);
getContentPane().add(button);
getContentPane().add(new JScrollPane( jpanel));
jpanel.setLayout(null);
this.setSize(780,550);
System.out.println(this.getSize());
       this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  
       this.setLocationRelativeTo(null);
       this.setVisible(true);
}
public static void main(String[] args) {
new ModuleAdd();
}
}