info.innerHTML="第"+times+"次验证码错误,请注意区分大小写 ";
}
document.forms["myform"].num.select();
}
function validata(obj){
var enter=true;
var info=document.getElementById("info");
var msg="";
if(obj.name.value.match(/^\s*$/g)){//如果未输入名字，提示
msg+="请输入您的姓名<br>";enter=false
}
if(obj.num.value.match(/^\s*$/g)){//如果未输入验证码，提示
msg+="请输入验证码<br>";enter=false
}
if(enter==false){
info.innerHTML=msg;
return false;
}
var url="num.jsp?num="+obj.num.value;
var newxmlhttp=new net.ContentLoader(url,subform,"","get",null,null);
return false;
}
function show(o){
//重载验证码
var timenow = new Date().getTime();
o.src="random.jsp?d="+timenow;
/*
//超时执行;
setTimeout(function(){
o.src="random.jsp?d="+timenow;
}
,20);
*/
}
</script>
<form action="img.jsp" name="myform" method="post" onsubmit="return validata(this);">
您的姓名：<input type="text" name="name" size=10> (为了更好地说明此例，特加姓名一项)<br>
验 证 码：<input type="text" name="num" size=10 maxlength="4"> <img src="random.jsp" id="random" align="" valign="absmiddle" hspace="5"> <a href="javascript:show(document.getElementById('random'))">验证码看不清< /a><br>
<br> <input type="submit" value=" 提交 "><br>
<div id=info style="color:red;padding:10px;font-size:12px;"></div>
</form>
</body>
</html>
2,num.jsp,反馈xmlhttp请求的页面
<%@ page contentType="text/html; charset=GBK" language="java" import="java.sql.*" errorPage="" pageEncoding="GBK"%>
<%
//set Chinese Char
//Cody by JarryLi@gmail.com;
//homepage:jiarry.126.com
request.setCharacterEncoding("GBK");
response.setCharacterEncoding("GBK");
response.setContentType("text/html; charset=GBK");
%>
<%
String num=request.getParameter("num");
String random=(String)session.getAttribute("random");
if(num!=null&&random!=null)
{
if(!num.equals(random))
{
/*
out.println("<script>alert('验证码错误！请重试。')</script>");
out.println("<script>history.go(-1)</script>");
//response.sendRedirect("img.jsp");
*/
out.print("validate_failed:"+random);
}
else
{
//out.println("<center>验证成功！</center>");
out.print("validate_successful:"+random);
}
}
%>
3,random.jsp,生成验证码图片的页面
<%@ page autoFlush="false" import="java.util.*,java.awt.*,java.awt.image.*,com.sun.image.codec.jpeg.*,java.util.*" %>
<%
//set Chinese Char
//Cody by JarryLi@gmail.com;
//homepage:jiarry.126.com
request.setCharacterEncoding("GBK");
