Java生成图片验证码

 Java生成图片验证码
import java.io.*;
import java.net.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.awt.*;
import java.awt.image.*;
import java.util.*;
import javax.imageio.*;
/**
 *
 * @author http://www.tot.name
 * @version
 */
public class Image extends HttpServlet {
    /** Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     * @param request servlet request
     * @param response servlet response
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        response.setContentType("image/jpeg");
        response.setHeader("Pragma","No-cache");
        response.setHeader("Cache-Control","no-cache");
        response.setDateHeader("Expires", 0);     
        HttpSession session=request.getSession();
        // 在内存中创建图象
        int width=60, height=20;
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        // 获取图形上下文
        Graphics g = image.getGraphics();
        //生成随机类
        Random random = new Random();
        // 设定背景色
        g.setColor(getRandColor(200,250));
        g.fillRect(0, 0, width, height);