①servlet代码绘画验证码图片
package com.util.servlet; import java.awt.Color; import java.awt.Font; import java.awt.Graphics; import java.awt.image.BufferedImage; import java.io.IOException; import java.util.Random; 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; public class AuthImageServlet extends HttpServlet { private static final long serialVersionUID = 1L; //设置字母的大小,大小 private Font mFont = new Font("Times New Roman", Font.PLAIN, 22); public void init() throws ServletException { super.init(); } 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); } public void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setHeader("Pragma","No-cache"); response.setHeader("Cache-Control","no-cache"); response.setDateHeader("Expires", 0); //表明生成的响应是图片 response.setContentType("image/jpeg"); int width=80, height=35;/*设置画布宽度和高度*/ BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics g = image.getGraphics(); Random random = new Random(); g.setColor(getRandColor(200,250)); g.fillRect(1, 1, width-1, height-1); g.setColor(new Color(102,102,102)); g.drawRect(0, 0, width-1, height-1); g.setFont(mFont); g.setColor(getRandColor(160,200)); //画随机线 for (int i=0;i<155;i++) { int x = random.nextInt(width - 1); int y = random.nextInt(height - 1); int xl = random.nextInt(6) + 1; int yl = random.nextInt(12) + 1; g.drawLine(x,y,x + xl,y + yl); } //从另一方向画随机线 for (int i = 0;i < 70;i++) { int x = random.nextInt(width - 1); int y = random.nextInt(height - 1); int xl = random.nextInt(12) + 1; int yl = random.nextInt(6) + 1; g.drawLine(x,y,x - xl,y - yl); } //生成随机数,并将随机数字转换为字母 String sRand=""; char ctmp = 0 ; for (int i=0;i<4;i++) { //ASCII码:65~90为26个大写英文字母,97~122号为26个小写英文字母,48~57为0到9十个阿拉伯数字 int itmp = 0; int codeNum = random.nextInt(9);//产生随机数,决定产生数字还是字母 if(codeNum % 2 == 0){//绘画大写字母 codeNum = random.nextInt(9);//产生随机数,决定产生大写字母还是小写字母 if(codeNum % 2 == 0){//产生小写字母 itmp = random.nextInt(26) + 97; ctmp = (char)itmp; }else{//产生大写字母 itmp = random.nextInt(26) + 65; ctmp = (char)itmp; } sRand += String.valueOf(ctmp);//将产生的字母字符拼接成字符串,存放到session中 }else{//产生数字 ctmp = (char)(random.nextInt(10)+48); sRand += String.valueOf(ctmp);//将产生的数字拼接成字符串,存放到session中 } g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110))); int intY = random.nextInt(8);//产生随机数控制纵坐标 g.drawString(String.valueOf(ctmp),15*i+10,16+intY);//控制每个字符的绘画位置 } HttpSession session = request.getSession(true); session.setAttribute("rand",sRand);/*将验证码放入session中进行验证*/ g.dispose(); ImageIO.write(image, "JPEG", response.getOutputStream()); } }
③web.xml的修改
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5"> <servlet> <servlet-name>AuthImageServlet</servlet-name> <servlet-class>com.util.servlet.AuthImageServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>AuthImageServlet</servlet-name> <url-pattern>/servlet/AuthImageServlet</url-pattern> </servlet-mapping> <servlet> <servlet-name>CheckCodeIsRight</servlet-name> <servlet-class>com.util.servlet.CheckCodeIsRightServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>CheckCodeIsRight</servlet-name> <url-pattern>/servlet/CheckCodeIsRight</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> </web-app>
④JSP页面的编写
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>验证码</title> <script type="text/javascript" src="./comm/js/jquery.js"></script> <script type="text/javascript"> $(function() { $("#submit").click(function() { var code = $("#code").val(); $.ajax({ url : "servlet/CheckCodeIsRight", type : "POST", data : {"code" : code}, dataType : "text", async : false,//同步执行 erro : function(data){alert("erro");}, success : function(data) { if(data == "1"){ alert("验证码输入正确"); }else{ alert("验证码输入有误!"); changeCode();s } } }); }); }) function changeCode() { var imgNode = document.getElementById("vimg"); imgNode.src = "servlet/AuthImageServlet?t=" + Math.random(); // 防止浏览器缓存的问题 } </script> </head> <body> <form action="checkServlet" method="post"> <label>输入验证码</label><br /> <input type="text" name="randomCode" id="code" /> <img style="cursor: pointer;" id="vimg" title="看不清?点击换一个" onclick="changeCode();" src="servlet/AuthImageServlet"> <br /> <input type="button" value="submit" id="submit"> </form> </body> </html>