，javaweb注册做验证码，如何弄

求助，javaweb注册做验证码，怎么弄
用javaweb做登录页面，做验证码怎么写啊？并且点击能够刷新，求完整方法并解释啊，还有验证码如果要配置xml什么的，怎么配置。谢谢了



[解决办法]
去这个传送门，有你想要的，但是它是整合了Struts2以后的验证码哦！
http://www.iteye.com/topic/300128
[解决办法]
servlet

Java code

package com.tjsoft.system.login;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.image.BufferedImage;import java.io.IOException;import java.io.OutputStream;import java.util.Random;import javax.imageio.ImageIO;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;public class ValidateServlet extends HttpServlet {    /**     * Constructor of the object.     */    public ValidateServlet() {        super();    }    /**     * Destruction of the servlet. <br>     */    public void destroy() {        super.destroy(); // Just puts "destroy" string in log        // Put your code here    }    /**     * The doGet method of the servlet. <br>     *     * This method is called when a form has its tag value method equals to get.     *      * @param request the request send by the client to the server     * @param response the response send by the server to the client     * @throws ServletException if an error occurred     * @throws IOException if an error occurred     */    public void doGet(HttpServletRequest request, HttpServletResponse response)            throws ServletException, IOException {        BufferedImage bi=new BufferedImage(75,25,BufferedImage.TYPE_INT_RGB);        Graphics g=bi.getGraphics();                g.fillRect(3, 3, 70, 20);        String line="";        Random rnd=new Random();        for(int i=0;i<5;i++){            line+=rnd.nextInt(10);        }        HttpSession session=request.getSession();        session.setAttribute("line", line);        g.setFont(new Font("黑体",Font.BOLD,20));        int x1 = 0;        int x2 = 0;        int y1 = 0;        int y2 = 0;        g.setColor(Color.gray);        for(int i = 0; i < 150; i ++){            x1 = rnd.nextInt(60)+3;            x2 = rnd.nextInt(70)+3;            y1 = rnd.nextInt(10)+3;            y2 = rnd.nextInt(20)+3;                        g.drawLine(x1, y1, x2, y2);        }        g.setColor(Color.RED);        g.drawString(line, 3, 20);        response.setContentType("image/jpeg");//将servlet设置成图片类型        //禁止缓存        response.setHeader("pragma", "no-cache");        response.setHeader("cache-control", "no-cache");        response.setDateHeader("expires", 0);                OutputStream os = response.getOutputStream();        //将图片写到客户端        ImageIO.write(bi, "jpg", os);            }}
[解决办法]
JScript code
var code; // 在全局 定义验证码function createCode() {    code = "";    var codeLength = 3;// 验证码的长度    var checkCode = document.getElementById("checkCode");    var selectChar = new Array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9);    // , 'A', 'B',    // 'C', 'D', 'E', 'F', 'G', 'G', 'I', 'J', 'K', 'L', 'M', 'N',    // 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y',    // 'Z');//所有候选组成验证码的字符，当然也可以用中文的    for ( var i = 0; i < codeLength; i++) {        var charIndex = Math.floor(Math.random() * 10);        code += selectChar[charIndex];    }    if (checkCode) {        checkCode.className = "code";        checkCode.value = code;        checkCode.blur();    }}function validate() {    var inputCode = document.getElementById("validCode").value;    if (inputCode.length <= 0) {        alert("请输入验证码！");        return false;    } else if (inputCode.toUpperCase() != code) {        alert("验证码输入错误！");        createCode();// 刷新验证码        return false;    }    form1.submit();}function assign() {}