testUser VerifyCodeServlet cn.itcast.vcode.servlet.VerifyCodeServlet LoginServlet cn.itcast.test.web.servlet.LoginServlet VerifyCodeServlet /VerifyCodeServlet LoginServlet /LoginServlet EncodingFilter cn.itcast.filter.EncodingFilter charset utf-8 EncodingFilter /* index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>My JSP 'form.jsp' starting page <%--1. 写表单，其中包含图片（验证码）2. 让图片显示出来： 把的src指向VerifyCodeServlet，你需要在web.xml中部署VerfiyCodeServlet3. 换一张--%>
package cn.itcast.test.web.servlet;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import cn.itcast.servlet.BaseServlet;public class LoginServlet extends BaseServlet { public String login(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { /* * 校验验证码 * 1. 获取表单中的验证码 * 2. 获取图片上的文字 */ String verifyCode = request.getParameter("verifyCode"); // VerifyCodeServlet会把真正的验证码保存到session中 String vcode = (String) request.getSession().getAttribute("vCode"); System.out.println(verifyCode.equalsIgnoreCase(vcode)); return "/form.jsp"; }} 第二种实现二维码验证
package com.atguigu.javaweb;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class CheckCodeServlet extends HttpServlet { private static final long serialVersionUID = 1L; protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //1. 获取请求参数: CHECK_CODE_PARAM_NAME String paramCode = request.getParameter("CHECK_CODE_PARAM_NAME"); //2. 获取 session 中的 CHECK_CODE_KEY 属性值 String sessionCode = (String)request.getSession().getAttribute("CHECK_CODE_KEY"); System.out.println(paramCode); System.out.println(sessionCode); //3. 比对. 看是否一致, 若一致说明验证码正确, 若不一致, 说明验证码错误 if(!(paramCode != null && paramCode.equals(sessionCode))){ request.getSession().setAttribute("message", "验证码不一致!"); response.sendRedirect(request.getContextPath() + "/index.jsp"); return; } System.out.println("受理请求!"); }}
package com.atguigu.javaweb; import java.awt.Color;import java.awt.Font;import java.awt.Graphics2D;import java.awt.image.BufferedImage;import java.io.IOException;import java.util.Random;import javax.imageio.ImageIO;import javax.servlet.ServletException;import javax.servlet.ServletOutputStream;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class ValidateColorServlet extends HttpServlet { public static final String CHECK_CODE_KEY = "CHECK_CODE_KEY"; private static final long serialVersionUID = 1L; //设置验证图片的宽度, 高度, 验证码的个数 private int width = 152; private int height = 40; private int codeCount = 6; //验证码字体的高度 private int fontHeight = 4; //验证码中的单个字符基线. 即：验证码中的单个字符位于验证码图形左上角的 (codeX, codeY) 位置处 private int codeX = 0; private int codeY = 0; //验证码由哪些字符组成 char [] codeSequence = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz23456789".toCharArray(); //初始化验证码图形属性 public void init(){ fontHeight = height - 2; codeX = width / (codeCount + 2); codeY = height - 4; } public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //定义一个类型为 BufferedImage.TYPE_INT_BGR 类型的图像缓存 BufferedImage buffImg = null; buffImg = new BufferedImage(width, height, BufferedImage.TYPE_3BYTE_BGR); //在 buffImg 中创建一个 Graphics2D 图像 Graphics2D graphics = null; graphics = buffImg.createGraphics(); //设置一个颜色, 使 Graphics2D 对象的后续图形使用这个颜色 graphics.setColor(Color.WHITE); //填充一个指定的矩形: x - 要填充矩形的 x 坐标; y - 要填充矩形的 y 坐标; width - 要填充矩形的宽度; height - 要填充矩形的高度 graphics.fillRect(0, 0, width, height); //创建一个 Font 对象: name - 字体名称; style - Font 的样式常量; size - Font 的点大小 Font font = null; font = new Font("", Font.BOLD, fontHeight); //使 Graphics2D 对象的后续图形使用此字体 graphics.setFont(font); graphics.setColor(Color.BLACK); //绘制指定矩形的边框, 绘制出的矩形将比构件宽一个也高一个像素 graphics.drawRect(0, 0, width - 1, height - 1); //随机产生 15 条干扰线, 使图像中的认证码不易被其它程序探测到 Random random = null; random = new Random(); graphics.setColor(Color.GREEN); for(int i = 0; i < 55; i++){ int x = random.nextInt(width); int y = random.nextInt(height); int x1 = random.nextInt(20); int y1 = random.nextInt(20); graphics.drawLine(x, y, x + x1, y + y1); } //创建 randomCode 对象, 用于保存随机产生的验证码, 以便用户登录后进行验证 StringBuffer randomCode; randomCode = new StringBuffer(); for(int i = 0; i < codeCount; i++){ //得到随机产生的验证码数字 String strRand = null; strRand = String.valueOf(codeSequence[random.nextInt(36)]); //把正在产生的随机字符放入到 StringBuffer 中 randomCode.append(strRand); //用随机产生的颜色将验证码绘制到图像中 graphics.setColor(Color.BLUE); graphics.drawString(strRand, (i + 1)* codeX, codeY); } //再把存放有所有随机字符的 StringBuffer 对应的字符串放入到 HttpSession 中 request.getSession().setAttribute(CHECK_CODE_KEY, randomCode.toString()); //禁止图像缓存 response.setHeader("Pragma", "no-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); //将图像输出到输出流中 ServletOutputStream sos = null; sos = response.getOutputStream(); ImageIO.write(buffImg, "jpeg", sos); sos.close(); }} Validate validateColorServlet com.atguigu.javaweb.ValidateColorServlet validateColorServlet /validateColorServlet CheckCodeServlet CheckCodeServlet com.atguigu.javaweb.CheckCodeServlet CheckCodeServlet /checkCodeServlet index.html index.htm index.jsp
<%@page import="java.util.Date"%><%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>Insert title here <%= session.getAttribute("message") == null ? "" : session.getAttribute("message")%>