jsp+Servlet验证码及验证
一个用jsp+Servlet+jquery+ajax实现的验证码,及验证是否正确。供初学者学习交流。
效果图:
源代码:
validate.jsp
<%@ 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>验证码</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"> <style type="text/css"> .error{ background: url(./images/invalid_line.gif) repeat-x bottom; border: 1px solid red; } </style> <script type="text/javascript" src="./js/jquery.js"></script> <script type="text/javascript"> $(function(){ $("#check").blur(function(){ $.ajax({ type:‘post‘, url:‘check‘, data: {input: $(this).val()}, dataType: "text/json", success: function(msg){ var ret = eval(‘(‘ + msg + ‘)‘); var success = ret.success; $("#tip").html(ret.message); if(!success){ $(this).val(‘‘); $("#image").attr(‘src‘,"validate?random="+Math.random()); $("#check").addClass("error"); $("#tip").css({‘color‘:‘red‘,‘font-family‘: ‘华文楷体‘}); }else{ $("#check").removeClass("error"); $("#tip").css({‘color‘:‘black‘,‘font-family‘: ‘华文楷体‘}); } } }); }); $("#image").click(function(){ $(this).attr(‘src‘,"validate?random="+Math.random()); }); }); </script> </head> <body> <input type="text" id="check" value=""> <div id="tip"> </div> <br> <img src="validate" id="image"> </body> </html>
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.5" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <servlet-mapping> <servlet-name>validate</servlet-name> <url-pattern>/validate</url-pattern> </servlet-mapping> <servlet> <servlet-name>validate</servlet-name> <servlet-class>test.MyValidateServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>check</servlet-name> <url-pattern>/check</url-pattern> </servlet-mapping> <servlet> <servlet-name>check</servlet-name> <servlet-class>test.CheckServlet</servlet-class> </servlet> </web-app>
ValidateCode.java
package util; import java.awt.Color; import java.awt.Font; import java.awt.Graphics; import java.awt.image.BufferedImage; import java.util.Random; public class ValidateCode { public static final int TYPE_NUM_ONLY = 0; public static final int TYPE_LETTER_ONLY = 1; public static final int TYPE_ALL_MIXED = 2; public static final int TYPE_NUM_UPPER = 3; public static final int TYPE_NUM_LOWER = 4; public static final int TYPE_UPPER_ONLY = 5; public static final int TYPE_LOWER_ONLY = 6; public static String generateTextCode(int type, int length, String exChars) { if (length <= 0) { return ""; } StringBuffer code = new StringBuffer(); int i = 0; Random r = new Random(); switch (type) { case 0: while (i < length) { int t = r.nextInt(10); if ((exChars == null) || (exChars.indexOf(t) < 0)) { code.append(t); i++; } } break; case 1: while (i < length) { int t = r.nextInt(123); if (((t >= 97) || ((t >= 65) && (t <= 90))) && ((exChars == null) || (exChars.indexOf((char) t) < 0))) { code.append((char) t); i++; } } break; case 2: while (i < length) { int t = r.nextInt(123); if (((t < 97) && ((t < 65) || (t > 90)) && ((t < 48) || (t > 57))) || ((exChars != null) && (exChars.indexOf((char) t) >= 0))) continue; code.append((char) t); i++; } break; case 3: while (i < length) { int t = r.nextInt(91); if (((t >= 65) || ((t >= 48) && (t <= 57))) && ((exChars == null) || (exChars.indexOf((char) t) < 0))) { code.append((char) t); i++; } } break; case 4: while (i < length) { int t = r.nextInt(123); if (((t >= 97) || ((t >= 48) && (t <= 57))) && ((exChars == null) || (exChars.indexOf((char) t) < 0))) { code.append((char) t); i++; } } break; case 5: while (i < length) { int t = r.nextInt(91); if ((t >= 65) && ((exChars == null) || (exChars.indexOf((char) t) < 0))) { code.append((char) t); i++; } } break; case 6: while (i < length) { int t = r.nextInt(123); if ((t >= 97) && ((exChars == null) || (exChars.indexOf((char) t) < 0))) { code.append((char) t); i++; } } } return code.toString(); } public static BufferedImage generateImageCode(String textCode, int width, int height, int interLine, boolean randomLocation, Color backColor, Color foreColor, Color lineColor) { BufferedImage bim = new BufferedImage(width, height, 1); Graphics g = bim.getGraphics(); g.setColor(backColor == null ? getRandomColor() : backColor); g.fillRect(0, 0, width, height); Random r = new Random(); if (interLine > 0) { int x = 0; int y = 0; int x1 = width; int y1 = 0; for (int i = 0; i < interLine; i++) { g.setColor(lineColor == null ? getRandomColor() : lineColor); y = r.nextInt(height); y1 = r.nextInt(height); g.drawLine(x, y, x1, y1); } } int fsize = (int) (height * 0.8D); int fx = height - fsize; int fy = fsize; g.setFont(new Font("Default", 0, fsize)); for (int i = 0; i < textCode.length(); i++) { fy = randomLocation ? (int) ((Math.random() * 0.3D + 0.6D) * height) : fy; g.setColor(foreColor == null ? getRandomColor() : foreColor); g.drawString(String.valueOf(textCode.charAt(i)), fx, fy); fx = (int) (fx + fsize * 0.9D); } g.dispose(); return bim; } public static BufferedImage generateImageCode(int type, int length, String exChars, int width, int height, int interLine, boolean randomLocation, Color backColor, Color foreColor, Color lineColor) { String textCode = generateTextCode(type, length, exChars); BufferedImage bim = generateImageCode(textCode, width, height, interLine, randomLocation, backColor, foreColor, lineColor); return bim; } private static Color getRandomColor() { Random r = new Random(); Color c = new Color(r.nextInt(255), r.nextInt(255), r.nextInt(255)); return c; } }
MyValidateServlet.java
package test; import java.awt.Color; import java.awt.image.BufferedImage; import java.io.IOException; import java.io.OutputStream; 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; import util.ValidateCode; public class MyValidateServlet extends HttpServlet { private static final long serialVersionUID = 1L; @Override protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { resp.setHeader("Pragma", "No-cache");// 设置响应头信息,告诉浏览器不要缓存此内容 resp.setHeader("Cache-Control", "no-cache"); resp.setDateHeader("Expire", 0); try { String textCode = ValidateCode.generateTextCode( ValidateCode.TYPE_ALL_MIXED, 6, null); BufferedImage image = ValidateCode.generateImageCode(textCode, 500, 100, 5, true, Color.GRAY, null, null); HttpSession session = req.getSession(true); session.setAttribute("captcha", textCode); resp.setContentType("image/jpeg"); OutputStream outputStream = resp.getOutputStream(); ImageIO.write(image, "jpeg", outputStream); } catch (Exception e) { e.printStackTrace(); } } }
CheckServlet.java
package test; 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; import javax.servlet.http.HttpSession; public class CheckServlet extends HttpServlet { private static final long serialVersionUID = 1L; @Override protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { resp.setCharacterEncoding("UTF-8"); resp.setContentType("text/html;chartset=UTF-8"); req.setCharacterEncoding("UTF-8"); String input = (String) req.getParameter("input"); HttpSession sess = req.getSession(); String captcha = (String) sess.getAttribute("captcha"); PrintWriter out = resp.getWriter(); if(input.toUpperCase().equals(captcha.toUpperCase())){ out.print("{‘success‘: true,‘message‘: ‘验证码正确!‘}"); }else{ out.print("{‘success‘: false,‘message‘: ‘验证码错误!‘}"); } out.flush(); out.close(); } }
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