jsp+ajax实现的局部刷新较验验证码(onblur事件触发较验)

程序员文章站 2022-05-03 15:40:41

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...

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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