jsp验证码

最新推荐文章于 2025-06-25 09:38:38 发布

原创最新推荐文章于 2025-06-25 09:38:38 发布 · 692 阅读

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#jsp #random #import #string #image #input

本文介绍了一个基于Java Web的验证码生成及验证系统实现细节。通过getImg.java生成包含随机字符的图片验证码，并在ver.jsp中展示，用户输入后由check.jsp进行校验。涉及随机颜色背景绘制、干扰线绘制及Session属性设置。

ver.jsp

web.xml

<servlet> <servlet-name>johnnyimg</servlet-name> <servlet-class>com.foxconn.getImg</servlet-class> </servlet> <servlet-mapping> <servlet-name>johnnyimg</servlet-name> <url-pattern>/joimg</url-pattern> </servlet-mapping>

getImg.java

package com.foxconn; import javax.servlet.*; import javax.servlet.http.*; import java.io.*; import java.awt.*; import java.awt.image.*; import java.util.*; import javax.imageio.*; public class getImg extends HttpServlet { private Font mFont = new Font("Arial Black", Font.PLAIN, 16); 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); response.setContentType("image/jpeg"); int width = 80, height = 18; 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)); 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); } 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); } String sRand = ""; for (int i = 0; i < 4; i++) { String tmp = getRandomChar(); sRand += tmp; g.setColor(new Color(20 + random.nextInt(110), 20 + random .nextInt(110), 20 + random.nextInt(110))); g.drawString(tmp, 15 * i + 10, 15); } HttpSession session = request.getSession(true); session.setAttribute("jorand", sRand); g.dispose(); ImageIO.write(image, "JPEG", response.getOutputStream()); } private String getRandomChar() { //int rand = (int) Math.round(Math.random() * 2); int rand = (int) Math.round(Math.random() * 2)+6; long itmp = 0; char ctmp = '/u0000'; switch (rand) { case 1: itmp = Math.round(Math.random() * 25 + 65); ctmp = (char) itmp; return String.valueOf(ctmp); case 2: itmp = Math.round(Math.random() * 25 + 97); ctmp = (char) itmp; return String.valueOf(ctmp); default: itmp = Math.round(Math.random() * 9); return String.valueOf(itmp); } } }

check.jsp

<% String inputnum = request.getParameter("inputnum"); String vernum = (String)session.getAttribute("jorand"); if(inputnum==null){inputnum="";} if(vernum==null){vernum="";} if(inputnum.equals(vernum)) { out.println("ver num is right"); } else { out.println("ver num is wrong"); } %>