servlet简单的验证码登录验证

来源：互联网发布：单片机电子密码锁编程编辑：程序博客网时间：2024/05/09 05:16

package com.bjsxt.check;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.image.BufferedImage;import java.io.ByteArrayOutputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.OutputStream;import java.io.PrintWriter;import java.util.Random;import javax.imageio.ImageIO;<pre name="code" class="java">package com.bjsxt.check;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class Check extends HttpServlet {public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {String checkCode = request.getParameter("checkCode");String name = request.getParameter("uname");String pwd = request.getParameter("pwd");String checkCode1 = (String) request.getSession().getAttribute("checkCode");//验证生成的验证码和用户输入的验证码是否一致,一致则登陆成功,否则失败if(checkCode!=null&&checkCode.equals(checkCode1)){request.getRequestDispatcher("/index.jsp").forward(request, response);}else{request.getRequestDispatcher("/checkcode.jsp").forward(request, response);}}}

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <base href="<%=basePath%>">        <title>My JSP 'checkcode.jsp' starting page</title>    <meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0">    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="This is my page"><!--<link rel="stylesheet" type="text/css" href="styles.css">-->  </head>  <script type="text/javascript" src="js/jquery-1.9.1.min.js"></script>  <script type="text/javascript">  $(function(){  $("#check").click(function(){  $("#check").attr("src",null);  $("#check").attr("src","/checkcode_03/checkCode?"+Math.random());  });  $("#change").click(function(){  $("#check").attr("src",null);  $("#check").attr("src","/checkcode_03/checkCode?"+Math.random());  return false;  });  });      </script>    <body>  <form action="check" method="post">  <table>  <tr><th>用户名</th><td><input type="text" value="" name="uname"/></td>  </tr>  <tr><th>密码</th><td><input type="password" value="" name="pwd"/></td>  </tr>  <tr><th>验证码</th><td><input type="text" value="" name="checkCode"/></td>  </tr>  <tr><th colspan="2"><img alt="验证码" src="/checkcode_03/checkCode" id="check"><a href="#" id="change" >看不清,换一张</a></th>  </tr>  <tr><th colspan="2"><input type="submit" value="提交"/>     <input type="reset" value="重置"/></th>  </tr>  </table>  </form>  </body></html>

import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.image.BufferedImage;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.util.Random;import javax.imageio.ImageIO;import javax.imageio.stream.ImageOutputStreamImpl;import javax.servlet.ServletException;import javax.servlet.ServletOutputStream;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;public class CheckCode extends HttpServlet {private static final long serialVersionUID = 1L;private static final int WIDTH = 100;private static final int HEIGHT = 30;private char[] checkCode = new char[4];private Random random = new Random();// 随机产生二维码字符四个public char[] getCheckCode() {String str = "abcdefghijklmnopqrstuvwxyz0123456789";for (int i = 0; i < 4; i++) {int index = random.nextInt(str.length());checkCode[i] = str.charAt(index);}return checkCode;}// 设置图片背景public void setBackGround(Graphics g) {// 设置背景色g.setColor(Color.GRAY);// 填充背景色g.fillRect(0, 0, WIDTH, HEIGHT);for (int i = 0; i < 120; i++) {// 设置干扰点颜色g.setColor(new Color(random.nextInt(255), random.nextInt(255),random.nextInt(255)));// 设置干扰点g.drawOval(random.nextInt(WIDTH), random.nextInt(HEIGHT), 1, 0);}}// 将验证码写在图片上public void DrawFont(Graphics g, char[] checkCode) {for (int i = 0; i < checkCode.length; i++) {g.setColor(new Color(random.nextInt(255), random.nextInt(255),random.nextInt(255)));g.setFont(new Font(null, Font.ITALIC | Font.BOLD, 30));g.drawString("" + checkCode[i], (int) (Math.random() + 25 * i),(int) (Math.random() * 5 + 27));}}public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {response.setContentType("image/jpeg");HttpSession session = request.getSession();BufferedImage image = new BufferedImage(WIDTH, HEIGHT,BufferedImage.TYPE_INT_RGB);Graphics g = image.getGraphics();char[] checkCode = getCheckCode();setBackGround(g);DrawFont(g, checkCode);g.dispose();ByteArrayOutputStream arrayOutputStream = new ByteArrayOutputStream();ImageIO.write(image, "JPEG", arrayOutputStream);byte[] buf = arrayOutputStream.toByteArray();ServletOutputStream sos = response.getOutputStream();sos.write(buf);response.setContentLength(buf.length);// 关闭各种流释放资源arrayOutputStream.close();sos.close();session.setAttribute("checkCode", new String(checkCode));}}

0 0