jsp+ajax实现的局部刷新较验验证码(onblur事件触发较验)

前台显示页面:

welcome.jsp

<%@ page language="java" cOntentType="text/html; utf-8"
 pageEncoding="utf-8"%>









  输入验证码：
  
  看不清

产生图片页面

authcode.jsp

<%@ page cOntentType="image/JPEG"
 import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*"
 pageEncoding="GBK"%>
<%!Color getRandColor(int fc, int bc) {//给定范围获得随机颜色 
  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); 
 }%>
<% 
 //设置页面不缓存 
 response.setHeader("Pragma", "No-cache"); 
 response.setHeader("Cache-Control", "no-cache"); 
 response.setDateHeader("Expires", 0); 
 // 在内存中创建图象 
 int width = 60, height = 20; 
 BufferedImage image = new BufferedImage(width, height, 
   BufferedImage.TYPE_INT_RGB); 
 // 获取图形上下文 
 Graphics g = image.getGraphics(); 
 //生成随机类 
 Random random = new Random(); 
 // 设定背景色 
 g.setColor(getRandColor(200, 250)); 
 g.fillRect(0, 0, width, height); 
 //设定字体 
 g.setFont(new Font("Times New Roman", Font.PLAIN, 18)); 
 //画边框 
 //g.setColor(new Color()); 
 //g.drawRect(0,0,width-1,height-1); 
 // 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到 
 g.setColor(getRandColor(160, 200)); 
 for (int i = 0; i <100; i++) { 
  int x = random.nextInt(width); 
  int y = random.nextInt(height); 
  int xl = random.nextInt(12); 
  int yl = random.nextInt(12); 
  g.drawLine(x, y, x + xl, y + yl); 
 } 
 // 取随机产生的认证码(4位数字) 
 String sRand = "";
 for (int i = 0; i <4; i++) { 
  String rand = String.valueOf(random.nextInt(10)); 
  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)));//调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成 
  g.drawString(rand, 13 * i + 6, 16); 
  System.out.println(rand);
 } 
 // 将认证码存入SESSION 
 session.setAttribute("code", sRand); 
 // 图象生效 
 g.dispose(); 
 // 输出图象到页面 
 ImageIO.write(image, "JPEG", response.getOutputStream()); 
%>

ajax动态验证页面

codevalidate.jsp

<%@ page language="java" import="java.util.*,java.util.*,java.text.*,com.neusoft.xkxt.dao.*,com.neusoft.xkxt.bean.*,com.neusoft.xkxt.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<%
 String authcode=request.getParameter("authcode");
 String code=(String)session.getAttribute("code");
 if(authcode.equals(code)){
 out.println("
√
");}
 else{
 out.println("
验证码不正确
");}
%>

希望本文所述对大家JSP程序设计有所帮助。

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