【下载文档:  用jsp页面生成随机的验证数字码示例.txt 】

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用jsp页面生成随机的验证数字码示例
checkNum.jsp 复制代码 代码如下: <%@ page language="java" import="java.util.*,java.sql.*" pageEncoding="UTF-8"%> <%@ page contentType="image/jpeg" import="java.awt.*,java.awt.image.*,javax.imageio.*"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <%! Color getRandColor(int fc,int bc)//给定范围随机选颜色 { 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); } %> <% response.setHeader("Pragma","No-cache");//设置页面不缓冲 response.setHeader("Cache-Control","no-cache"); response.setDateHeader("Expires",0); int width=60,height=20; BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB); Graphics g = image.getGraphics();//获取图像上下文 Random random = new Random();//生成随机对象 g.setColor(getRandColor(200,250)); g.fillRect(0,0,width,height); g.setFont(new Font("Times New Roman",Font.PLAIN,18));//设置字体 for(int i=0;i<155;i++) { int x=random.nextInt(width); int y=random.nextInt(height); int x1 = random.nextInt(12); int y1 = random.nextInt(12); g.drawLine(x,y,x+x1,y+y1); } //随机产生验证码 String sRand = ""; for(int i=0;i<4;i++) { String rand = String.valueOf(random.nextInt(10)); sRand+=rand; //将验证码显示到图像中 g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110))); //设置显示随机数的颜色 g.drawString(rand,13*i+6,16); } //将验证码存放到session中 session.setAttribute("rand",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(); %> 可以在登录login.jsp下直接通过： 这种格式调用； 验证码: