ajax和struts结合验证用户名是否存在-优快云博客

ajax和struts结合验证用户名是否存在
【标签：ajax,apache,jsp,struts,getwriter 】【发布时间：2008-01-16 】上一篇下一篇

jsp页面代码

<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<TITLE>Ajax验证用户名是否存在例子</TITLE>
<script>

//设一个变量

var XMLHttpReq=false;
//创建一个XMLHttpRequest对象
function createXMLHttpRequest(){
if(window.XMLHttpRequest){ //Mozilla
XMLHttpReq=new XMLHttpRequest();
}
else if(window.ActiveXObject){
try{
XMLHttpReq=new ActiveXObject("Msxml2.XMLHTTP");
}catch(e){
try{
XMLHttpReq=new ActiveXObject("Microsoft.XMLHTTP");
}catch(e){}
}
}
}
//发送请求函数
function send(url){
createXMLHttpRequest();
XMLHttpReq.open("get",url,true);
XMLHttpReq.onreadystatechange=proce; //指定响应的函数
XMLHttpReq.send(null); //发送请求
}
function proce(){
if(XMLHttpReq.readyState==4){ //对象状态
if(XMLHttpReq.status==200){//信息已成功返回，开始处理信息

var root=XMLHttpReq.responseXML;
var res=root.getElementsByTagName("content")[0].firstChild.data;
var test=root.getElementsByTagName("test")[0].firstChild.data;
window.alert(res);
window.alert("测试显示："+test);

//var xmlReturn = XMLHttpReq.responseText;
//window.alert(xmlReturn);
}else{
window.alert("所请求的页面有异常");
}
}
}
//身份验证
function check(){
var name=document.getElementById("name").value;

if(name==""){
alert("请输入姓名!");
return false;
}
else{
//send('login?name='+name);
document.getElementById("load").style.display='';
send('loginAction.do?name='+name);
document.getElementById("load").style.display='none';
}
}

</script>
</head>

<body>
<form action="login" method="post">
<table>
<tr><td>姓名: <input id="name" type="text" name="name"/><p>
<div id=load style="display:none; position:absolute;right:0px;top:0px;background:#FF5B5B;border:1px solid">正在验证用户名,请稍后……</div><p>
<input type="button" value="检测!" onClick="check()"/>
</td>
</tr>
</table>
</form>
</body>
</html>

action代码

package tt;

import java.io.UnsupportedEncodingException;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

public class LoginAction extends Action {
public ActionForward execute(ActionMapping mapping, ActionForm actionform,
HttpServletRequest request, HttpServletResponse response) {

try {
request.setCharacterEncoding("gb2312");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
try{
String msgStr="";
response.setContentType("text/xml;charset=GB2312");
response.setHeader("Cache-Control","no-cache");
String name=(String)request.getParameter("name");
System.out.println("name = "+name);
if("gong".equals(name)){ //找查数据库中有无该用户名
msgStr ="对不起,此用户名已经存在,请更换用户名注册!";
}else{
msgStr ="用户未被注册,可以使用!";
}
response.getWriter().println("<?xml version='1.0' encoding='GB2312' ?>");
response.getWriter().println("<root>");
response.getWriter().println("<content>");
response.getWriter().print(msgStr);
response.getWriter().println("</content>");
response.getWriter().println("<test>");
response.getWriter().println("哈哈，我在测试呢！");
response.getWriter().println("</test>");
response.getWriter().println("</root>");
response.getWriter().close();
}catch(Exception ex){

}
return null;

}
}