jsp+ajax实现的局部刷新较验验证码(onblur事件触发较验)

2020-07-27 21:29:27

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本文实例讲述了jsp+ajax实现的局部刷新较验验证码(onblur事件触发较验)。分享给大家供大家参考，具体如下：

前台显示页面:

welcome.jsp

<%@ page language="java" contentType="text/html; 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>修改个人信息</title><script>function createXMLHttpRequest() { //表示当前浏览器不是ie,如ns,firefox if(window.XMLHttpRequest) {  xmlHttp = new XMLHttpRequest(); } else if (window.ActiveXObject) {  xmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); }}function validate(field) { var div=document.getElementById("divbid");// var reg=/[^A-Za-z0-9_]{7,10}/g; if (field.value.length != 0) {  //创建XMLHttpRequest  createXMLHttpRequest();  var url = "codevalidate.jsp?authcode=" + field.value + "×tamp=" + new Date().getTime();//加时间戳防止缓存重复  xmlHttp.open("GET", url, true);  //方法地址，处理完成后自动调用，回调  xmlHttp.onreadystatechange=function() { //匿名函数   if(xmlHttp.readyState == 4) { //Ajax引擎初始化成功    if (xmlHttp.status == 200) { //http协议成功     document.getElementById("divbid").innerHTML =xmlHttp.responseText;    }else {     alert("请求失败，错误码=" + xmlHttp.status);    }   }  };  //将参数发送到Ajax引擎  xmlHttp.send(null); }else {   div.innerHTML="<div class=/"wrong/">验证码不能为空</div>" }}function reloadImage(imgurl){ var getimagecode=document.getElementById("codeimg"); getimagecode.src= imgurl + "?id=" + Math.random();  var code=<%=session.getAttribute("code")%>;  alert(code)}</script></head><body><form action="authcode.jsp" method="post" name="loginform">  输入验证码：<input type="text" name="authcode" id="authcode" maxlength="4" size="10" onblur="validate(this)" ><span id="divbid"></span>  <img id="codeimg" name="codeimg" border=0 src="authcode.jsp">  <a href="javascript:reloadImage('authcode.jsp')">看不清</a><br/></form><script language="javascript" type="text/javascript">function reloadImage(imgurl){ var getimagecode=document.getElementById("codeimg"); getimagecode.src= imgurl + "?id=" + Math.random(); var code=<%=session.getAttribute("code")%>; alert(code)}</script></body></html>

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("<div class='right'>√</div>");}  else{  out.println("<div class='wrong'>验证码不正确</div>");} %>

希望本文所述对大家JSP程序设计有所帮助。

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