struts+ajax ,一个Ajax验证用户名是否存在的例子

lehsyh · 发表于 2013-1-23 02:38:09

[table=98%][tr][td]<div class="cnt">1.index.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!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;
window.alert(res);
    
//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('login.do?name='+name);
   document.getElementById("load").style.display='none';
   }
    }

   </script>
</head>
<body>
<form action="login" method="post">
   <table>
   <tr><td>姓名:&nbsp;<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!" />
   </td>
    </tr>
    </table>
    </form>
</body>
</html>
2.struts-config.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 1.2//EN" "http://struts.apache.org/dtds/struts-config_1_2.dtd">
<struts-config>
<data-sources />
<form-beans >
<form-bean name="loginForm" type="com.ylsf.struts.form.LoginForm" />
</form-beans>
<global-exceptions />
<global-forwards />
<action-mappings >
<action
    attribute="loginForm"
    input="/index.jsp"
    name="loginForm"
    path="/login"
    scope="request"
    type="com.ylsf.struts.action.LoginAction" />
</action-mappings>
<message-resources parameter="com.ylsf.struts.ApplicationResources" />
</struts-config>
3.LoginForm.java
package com.ylsf.struts.form;
import org.apache.struts.action.ActionForm;
public class LoginForm extends ActionForm{
private String username;
public String getUsername() {
   return username;
}
public void setUsername(String username) {
   this.username = username;
}
}
4.LoginAction.java
package com.ylsf.struts.action;
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;
import com.ylsf.struts.form.LoginForm;

public class LoginAction extends Action {
public ActionForward execute(ActionMapping mapping, ActionForm form,
   HttpServletRequest request, HttpServletResponse response) {
//LoginForm loginForm = (LoginForm) form;// TODO Auto-generated method stub
try {
    request.setCharacterEncoding("UTF-8");
} catch (UnsupportedEncodingException e) {
    e.printStackTrace();
}
try{
    String msgStr="";
    response.setContentType("text/xml;charset=UTF-8");
    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='UTF-8' ?>");
    response.getWriter().println("<root>");
    response.getWriter().println("<content>");
    response.getWriter().print(msgStr);
    response.getWriter().println("</content>");
    response.getWriter().println("</root>");
    response.getWriter().close();
    }catch(Exception ex){
    }
return null;
}
}
http://hi.baidu.com/goylsf/blog/item/21c3d6d8cedf643032fa1cd5.html

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