1、产生验证码jsp代码
<%@ page contentType="image/jpeg" language="java" import="java.util.*,java.awt.*,java.awt.image.*,javax.imageio.*" pageEncoding="utf-8"%> <%! 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); } %> <% //设置页面不缓存 response.setHeader("Pragma","no-cache"); response.setHeader("Cache-Control","no-catch"); response.setDateHeader("Expires",0); //在内存中创建图象 int width = 60; int height = 20; BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB); //创建图象 Graphics g = image.getGraphics(); //生成随机对象 Random random = new Random(); //设置背景色 g.setColor(getRandColor(200,250)); g.fillRect(0,0,width,height); //设置字体 g.setFont(new Font("Tines Nev Roman",Font.PLAIN,18)); //随机产生干扰线 g.setColor(getRandColor(160,200)); for(int i = 0; i < 255; i++){ int x = random.nextInt(width); int y = random.nextInt(height); int xl = random.nextInt(12); int yl = random.nextInt(12); } //随机产生认证码,4位 String ch = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; String sRand = ""; for(int i = 0; i < 4; i++){ String rand = String.valueOf(ch.charAt(random.nextInt(ch.length()))); sRand += rand; //将认证码显示到图象中 g.setColor(new Color(20 + random.nextInt(110),20 + random.nextInt(110),20 + random.nextInt(110))); g.drawString(rand,13*i+6,16); } //验证码存到session中,key=rCode session.setAttribute("rCode",sRand); //图像生效 g.dispose(); //输出图像到页面 ImageIO.write(image,"JPEG",response.getOutputStream()); out.clear(); out = pageContext.pushBody(); %>
2、显示验证码jsp代码
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> <script> function reImg() { document.getElementById("img").src="number.jsp?code=" + Math.random(); } </script> </head> <body> <img src="number.jsp" id="img" onclick="reImg()"/> </body> </html>