<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%@ page contentType="text/html" %>
<%@ page import="java.util.regex.Pattern" %>
<%@ page import="java.util.regex.Matcher" %>
 
 
 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<body >
 
    <form action="login.jsp" method="post">
        用户名：<input type="text" name="name" value=""><br>
        密码：<input type="password" name="pwd"><br>
        验证码：<img src="number.jsp"/>
          <input type="text" name="code"/>
         
        <input type="submit" name="login" value="登录"><br>
    </form>
</body>
</html>

//验证码
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
    //获取登录的用户名
    String name = request.getParameter("name");
    //获取登录密码
    String pwd = request.getParameter("pwd");
    //判断
 
    if (name.equals("zzs") && pwd.equals("123456"))
        //转发到ok页面
        request.getRequestDispatcher("ok.jsp").forward(request,response);
    else
        //转发到no页面
        request.getRequestDispatcher("no.jsp").forward(request,response);
%>
<%@ page contentType="image/jpeg" language="java" import="java.util.*,java.awt.*,java.awt.image.*,javax.imageio.*" pageEncoding="utf-8"%>
 
<%!
    Color getRandColor(int fc,int bc){
        Random random = new Random();
        if(fc > 255){
            fc = 255;
        }
        if(bc < 255){
            bc = 255;
        }
        int r = fc +random.nextInt(bc-fc);
        int g = fc +random.nextInt(bc-fc);
        int b = fc +random.nextInt(bc-fc);
 
 
        return new Color(r,g,b);
    }
%>
 
<%
    //设置页面不缓存
    response.setHeader("Pragma","no-cache");
    response.setHeader("Cache-Control","no-catch");
    response.setDateHeader("Expires",0);
 
    //在内存中创建图象
    int width = 60;
    int height = 20;
    BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
 
    //创建图象
    Graphics g = image.getGraphics();
    //生成随机对象
    Random random = new Random();
    //设置背景色
    g.setColor(getRandColor(200,250));
    g.fillRect(0,0,width,height);
    //设置字体
    g.setFont(new Font("Tines Nev Roman",Font.PLAIN,18));
    //随机产生干扰线
    g.setColor(getRandColor(160,200));
    for(int i = 0; i < 255; i++){
        int x = random.nextInt(width);
        int y = random.nextInt(height);
        int xl = random.nextInt(12);
        int yl = random.nextInt(12);
    }
    //随机产生认证码,4位数字
    String sRand = "";
    for(int i = 0; i < 4; i++){
        String rand = String.valueOf(random.nextInt(10));
        sRand  += rand;
        //将认证码显示到图象中
        g.setColor(new Color(20 + random.nextInt(110),20 + random.nextInt(110),20 + random.nextInt(110)));
        g.drawString(rand,13*i+6,16);
    }
    session.setAttribute("rCode",sRand);
    //图像生效
    g.dispose();
    //输出图像到页面
    ImageIO.write(image,"JPEG",response.getOutputStream());
    out.clear();
    out = pageContext.pushBody();
%>