前端界面实现（由于验证码是动态获取所以用jsp格式）
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <base href="/Mvcpro/"/> <meta charset="UTF-8"> <title>Insert title here</title> <script type="text/javascript" src="js/jquery.min.js"></script> </head> <body> <span>${msg}</span> <form action="emp/login" method="POST"> <fieldset> <legend>请登录！</legend> 用户名：<input type="text" name="username" placehodler="输入用户名"><br><br> 密 码: <input type="password" name="pwd" placehodler="输入密码"><br><br> <img alt="图片不存在" src="imgCode" height="40px"><a href="javascript:void"> 看不清，换一张！</a><br><br> 验证码：<input type="text" name="code"> <br><br> <input type="submit" value="提交"> <input type="reset" value="重置"> </fieldset> </form> <script type="text/javascript"> $(function(){ $("form a").click(function(){//为a标签绑定了一个单机事件 $("form img").attr("src","imgCode?ran="+new Date().getTime()); }) }) </script> </body> </html>
用于验证码图片所编写的工具类
package com.sxt.mvcpro.util; 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.servlet.ServletException; import javax.servlet.ServletOutputStream; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; @WebServlet("/imgCode") public class RandomCode extends HttpServlet { private static final long serialVersionUID = 1L; private static int WIDTH = 102;//定义验证图片的宽度 private static int HEIGHT = 50;//定义验证图片的高度 public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { HttpSession session = request.getSession(); response.setContentType("image/jpeg"); ServletOutputStream sos = response.getOutputStream(); response.setHeader("Pragma", "No-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB); Graphics g = image.getGraphics(); char[] rands = generateCheckCode(); drawBackground(g); drawRands(g, rands); g.dispose(); ByteArrayOutputStream bos = new ByteArrayOutputStream(); ImageIO.write(image, "JPEG", bos); byte[] buf = bos.toByteArray(); response.setContentLength(buf.length); sos.write(buf); //锟斤拷锟斤拷锟缴碉拷锟斤拷证锟斤拷图片写锟斤拷页锟斤拷 bos.close(); sos.close(); //锟斤拷锟斤拷锟缴碉拷锟斤拷证锟诫保锟芥到session session.setAttribute("rand", new String(rands)); } private void drawBackground(Graphics g) { g.setColor(new Color(0xDCDCDC)); g.fillRect(0, 0, WIDTH, HEIGHT); for (int i = 0; i < 120; i++) { int x = (int) (Math.random() * WIDTH); int y = (int) (Math.random() * HEIGHT); int red = (int) (Math.random() * 255); int green = (int) (Math.random() * 255); int blue = (int) (Math.random() * 255); g.setColor(new Color(red, green, blue)); g.drawOval(x, y, 1, 0); } } private void drawRands(Graphics g, char[] rands) { // g.setColor(Color.BLUE); Random random = new Random(); int red = random.nextInt(110); int green = random.nextInt(50); int blue = random.nextInt(50); g.setColor(new Color(red, green, blue)); g.setFont(new Font(null, Font.ITALIC | Font.BOLD, 30)); g.drawString("" + rands[0], 5, 35); g.drawString("" + rands[1], 25, 34); g.drawString("" + rands[2], 45, 36); g.drawString("" + rands[3], 65, 33); } private char[] generateCheckCode() { String chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"; char[] rands = new char[4]; for (int i = 0; i < 4; i++) { int rand = (int) (Math.random() * 36); rands[i] = chars.charAt(rand); } return rands; } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doGet(request, response); } }
servlet层代码编写
@Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { String username=req.getParameter("username"); String pwd=req.getParameter("pwd"); String ranCode=req.getParameter("code"); //先判断验证码是否正确 if (ranCode.equalsIgnoreCase((String)req.getSession().getAttribute("rand"))) { if ("smith".equals(username)&&"1234".equals(pwd)) { req.getSession().setAttribute("name", username); //跳转到首页 resp.sendRedirect("/Mvcpro/pages/welcome.jsp"); }else { req.setAttribute("msg", "用户名密码不正确！"); req.getRequestDispatcher("/pages/login.jsp").forward(req, resp); } } } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { this.doGet(req, resp); }
总的来说借助所编写的工具类控制层的代码相对变得比较简洁，可塑性强，在工具类花的时间会较多，可以直接调用，后期与其他页面相结合也较为方便。