鱼跃于渊

First know how, Second know why !
posts - 0, comments - 1, trackbacks - 0, articles - 49

ajax 验证用户名(以JSP中)

Posted on 2008-09-24 15:58 鱼跃于渊 阅读(711) 评论(0)  编辑  收藏 所属分类: 平时小练习

login.html : 
        
            

<!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>Insert title here</title>

<script type="text/javascript">
 function checkname(){
  //alert("test") ;
  document.getElementById("msg").innerHTML="<img src=\"images/fwf3.JPG\" />" ;
  var url = "checklogin.jsp?username=" + document.forms[0].username.value ;
  //alert(url) ;
  if(window.XMLHttpRequest){
  xhr = new XMLHttpRequest() ;
  }else{
   if(window.ActiveXObject){
    try{
     xhr = new ActiveXObject("Microsoft.XMLHttpRequest") ;
    }catch(e){}
   }
  }
  if(xhr){
   xhr.onreadystatechange = showContents ;
   xhr.open("GET", url, true) ;
   xhr.send(null) ;
  }else{
   document.getElementById("msg").innerHTML = "sorry ! but your pc coundn't create a xhr object !" ;
  }
 }
 
 function showContents(){
 if(xhr.readyState == 4){
  if(xhr.status == 200){
   //alert(xhr.responseXML.contentType) ;
   //var outMsg = xhr.responseText ;
   //if(xhr.responseXML && xhr.responseXML.contentType == "text/xml"){
    var outMsg = xhr.responseXML.getElementsByTagName("msg")[0].childNodes[0].nodeValue ;
   //}else{
    //var outMsg = xhr.responseText ;
   //}
   //alert(outMsg) ;
   if(outMsg == "validate"){
    document.getElementById("msg").innerHTML = "<font color=green><strong>用户名正确 </strong></font>" ;
   }else{
    document.getElementById("msg").innerHTML = "<font color=red><strong>用户名不正确 </strong></font>" ;
   }
   
  }else{
   var outMsg = "there was a problem on your server : status = " + status ;
  }
 }
}
</script>

</head>
<body>
<center>
 <form action="checklogin.jsp">
  username : <input type="text" name="username" onblur="checkname() ;" /><span><div id="msg"></div></span><br><br>
  password : <input type="password" name="password" /><br><br>
  <input type="submit" value="submit" />
 </form>
</center>
</body>
</html>


checklogin.jsp


 
<%@ page import="java.sql.*" %>
   
<%
 response.setContentType("text/xml") ;
 response.setCharacterEncoding("GB18030") ;
 response.setHeader("catch-control", "no-store") ;
 response.setDateHeader("Expires", 0) ;
 
 String username = request.getParameter("username") ;

 
 Connection conn = null ;
 String login = "" ;
 try{
  Class.forName("com.mysql.jdbc.Driver") ;
  conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/testuser?user=root&password=110110") ;
  Statement stmt = conn.createStatement() ;
  String sql = "select count(*) from ruser where username = '" + username + "'" ;
  System.out.println(sql) ;
  ResultSet rs = stmt.executeQuery(sql) ;
  rs.next() ;
  int count = rs.getInt(1) ;
  if(count > 0){
   login = "validate" ;
  }else{
   login="novalidate" ;
  }
 }catch(ClassNotFoundException ex){
  ex.printStackTrace() ;
 }catch(SQLException ex){
  ex.printStackTrace() ;
 }
 
 //System.out.println(request.getParameter("username")) ;
 response.getWriter().write("<msg>" + login + "</msg>") ;
%>
   




        

只有注册用户登录后才能发表评论。


网站导航: