修改例W14E6，使得当鼠标在窗口中点击任何位置时，都会将按钮放在以点击位置为中心的位置，并在文本域中显示中心位置的坐标。
import java.awt.*;
import java.awt.event.*;
import javax.swing.SwingUtilities;

public class W14E6{

    public static void main(String[] args) {
        MyWindow myWin = new MyWindow("鼠标运动事件测试");
        
    }   
   
}

class MyWindow extends Frame implements MouseMotionListener{
    Button b;
    TextArea ta;
   
    MyWindow(String s){
        super(s);
        setLayout(new FlowLayout());
        setBounds(200, 100, 600, 300);
        b = new Button("按钮");
        add(b);
        ta = new TextArea();
        add(ta);
        b.addMouseMotionListener(this);
        ta.addMouseMotionListener(this);
        addWindowListener(new WindowAdapter(){
            public void windowClosing(WindowEvent e){
                System.exit(0);
            }
        });
        setVisible(true);
    }
   
    public void mouseDragged(MouseEvent e){
        int x,y,w,h;
        Component c = (Component)e.getSource();
        e = SwingUtilities.convertMouseEvent(c,e,this);
        x = e.getX();
        y = e.getY();
        w=c.getSize().width;
        h=c.getSize().height;
        c.setLocation(x-w/2,y-h/2);   
    }
   
    public void mouseMoved(MouseEvent e){}
        
}