怎样在图片上画线?JAVA
我想问下,怎样加载一个图片并在图片上画线? 
 我是想实现跟踪其它机子的鼠标位置显示在自己的机子上,鼠标的实时变化坐标我已经获得,但不知道怎么加载一张图片,在图片上根据鼠标坐标的位置划个十字线.但不知道怎么实现,画线是不是一定要在CANVAS上画啊,可CANVAS又不能设背景图片,该怎么实现啊,有没有谁知道请帮我解决下,急.能给示例代码最好
------解决方案--------------------任何componet上都能画 重载paint函数 在paint函数里画
------解决方案--------------------你把图片画上去,然后再画线就行了
------解决方案--------------------drawline
------解决方案--------------------在JSP上加载applet程序 
  <applet code= "你的applte程序的class " width=320 height=220>  
 在JSP上加载图片 
  <param name= "imgName " value= "lines.jpg ">
------解决方案--------------------import java.awt.Graphics; 
 import java.awt.Image; 
 import java.awt.event.MouseEvent;   
 import javax.swing.JFrame; 
 import javax.swing.JPanel; 
 import javax.swing.event.MouseInputListener; 
 class ImagePanel extends JPanel implements MouseInputListener 
 { 
 	private Image img; 
 	private int x = 0,y = 0; 
 	public ImagePanel(Image img) 
 	{ 
 		this.img = img; 
 		addMouseListener(this); 
 	} 
 	public void paint(Graphics g) 
 	{ 
 		g.drawImage(img,0,0,null); 
 		if(x != 0 && y != 0) 
 		{ 
 			g.drawLine(x-5,y,x+5,y); 
 			g.drawLine(x,y-5,x,y+5); 
 		} 
 	}  	 
 	public void drawLine(int x,int y) 
 	{ 
 		this.x = x; 
 		this.y = y; 
 		repaint(); 
 	}   
 	public void mouseClicked(MouseEvent e) {  		 
 		int x = e.getPoint().x; 
 		int y = e.getPoint().y; 
 		drawLine(x,y); 
 	}   
 	public void mousePressed(MouseEvent e) {  		 
 	}   
 	public void mouseReleased(MouseEvent e) {  		 
 	}   
 	public void mouseEntered(MouseEvent e) {  		 
 	}   
 	public void mouseExited(MouseEvent e) {  		 
 	}   
 	public void mouseDragged(MouseEvent e) {  		 
 	}   
 	public void mouseMoved(MouseEvent e) {   
 	}  	 
 } 
 public class ImageLineTest extends JFrame {  	 
 	ImagePanel p = null;  	 
 	public void drawLine(int x,int y) 
 	{ 
 		p.drawLine(x,y); 
 	}  	 
 	public void init() 
 	{ 
 		setSize(200,100); 
 		setDefaultCloseOperation(EXIT_ON_CLOSE); 
 		Image img = getToolkit().getImage( "c:\\mao.jpg "); 
 		p = new ImagePanel(img);	 
 		this.getContentPane().add(p); 
 		show(); 
 	}  	 
 	public static void main(String[] arg) throws Exception 
 	{		 
 		ImageLineTest test = new ImageLineTest(); 
 		test.init(); 
 	} 
 }     
 这样就可以了,运行以后点击某个地方就会出现一个十字线