验证码生成器(四位)
package com.hrm.houfei.utils; 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; import javax.servlet.http.HttpSession; public class ValidateCodeServlet extends HttpServlet { // 常量 private static final long serialVersionUID = 1L; // 验证码图片的宽度。 private int width = 60; // 验证码图片的高度。 private int height = 20; // 验证码字符个数 private int codeCount = 4; private int x = 0; // 字体高度 private int fontHeight; private int codeY; char[] codeSequence = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z' }; /** * 构造方法 */ public ValidateCodeServlet() { super(); } /** * 初始化 */ public void init() throws ServletException { // 宽度 String strWidth = this.getInitParameter("width"); // 高度 String strHeight = this.getInitParameter("height"); // 字符个数 String strCodeCount = this.getInitParameter("codeCount"); // 将配置的信息转换成数值 try { if (strWidth != null && strWidth.length() != 0) { width = Integer.parseInt(strWidth); } if (strHeight != null && strHeight.length() != 0) { height = Integer.parseInt(strHeight); } if (strCodeCount != null && strCodeCount.length() != 0) { codeCount = Integer.parseInt(strCodeCount); } } catch (NumberFormatException e) { } x = width / (codeCount + 2); fontHeight = height - 1; codeY = height - 4; } /** * 服务 */ public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } /** * 服务 */ public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 定义图像buffer BufferedImage buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics2D g = buffImg.createGraphics(); // 创建一个随机数生成器类 Random random = new Random(); // 将图像填充为白色 g.setColor(Color.WHITE); g.fillRect(0, 0, width, height); // 创建字体，字体的大小应该根据图片的高度来定。 Font font = new Font("宋体", Font.BOLD, fontHeight); // 设置字体。 g.setFont(font); // 画边框。 g.setColor(Color.GRAY); g.drawRect(0, 0, width - 1, height - 1); // 随机产生160条干扰线，使图象中的认证码不易被其它程序探测到。 g.setColor(Color.GRAY); for (int i = 0; i < 40; i++) { int x = random.nextInt(width); int y = random.nextInt(height); int xl = random.nextInt(2); int yl = random.nextInt(2); g.drawLine(x, y, x + xl, y + yl); } // randomCode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 = new StringBuffer(); int red = 0, green = 0, blue = 0; // 随机产生codeCount数字的验证码。 for (int i = 0; i < codeCount; i++) { // 得到随机产生的验证码数字。 String strRand = String.valueOf(codeSequence[random.nextInt(62)]); // 产生随机的颜色分量来构造颜色值，这样输出的每位数字的颜色值都将不同。 red = random.nextInt(127); green = random.nextInt(127); blue = random.nextInt(127); // 用随机产生的颜色将验证码绘制到图像中。 g.setColor(new Color(red, green, blue)); g.drawString(strRand, (i + 1) * x, codeY); // 将产生的四个随机数组合在一起。 randomCode.append(strRand); } // 将四位数字的验证码保存到Session中。 request.getSession().setAttribute("validateCode", randomCode.toString()); System.out.println("----------------------->动态生成了验证码:"+randomCode.toString()); //session.setAttribute("validateCode", randomCode.toString()); // 禁止图像缓存。 response.setHeader("Pragma", "no-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); response.setContentType("image/jpeg"); // 将图像输出到Servlet输出流中。 ServletOutputStream sos = response.getOutputStream(); ImageIO.write(buffImg, "jpeg", sos); sos.flush(); sos.close(); } /** * 销毁 */ public void destroy() { super.destroy(); } }
以上是图片生成的servlet
<%@ 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 'index.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" mce_href="styles.css"> --> <mce:script type="text/javascript"><!-- function refreshValidateCode(){ var _img=document.getElementById("validateCodeImage"); _img.src=""; setTimeout(function(){ _img.src="validateCodeServlet"; },10); } function login(){ alert('${sessionScope.validateCode}'); } // --></mce:script> </head> <body> <form action=""> <table> <tr> <td> <span class="myFont">验证码:</span></td> <td><input name="validCode" type="text" class="loginCheckCodeTextField" id="textfield3"> <img id="validateCodeImage" width="60" height="20" alt="验证码" src="validateCodeServlet" mce_src="validateCodeServlet" /> <input name="button2" type="button" class="loginBtn" id="button2" class="loginBtn" value="看不清" onclick="refreshValidateCode();"></td> <td> </td> <td> </td> </tr> <tr><td> <input name="button" type="submit" style="widows: 100px;" mce_style="widows: 100px;" class="loginBtn" id="button" value="提交" /> </td></tr> </table> </form> </body> </html>
以上是jsp页面
在要提交的action中 只需要 //实际验证码
String validCode = request.getParameter("validCode");即可