Ajax做的小例子
學習Ajax好多天了,終于做出一個小例子。
環境
eclipse3.2
tomcat6.0
jdk1.5
下面簡單介紹下關于Ajax的主要實現部分
index.jsp
<%@ page contentType="text/html; charset=gb2312" language="java"
import="java.sql.*" errorPage=""%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>用戶注冊</title>
<style type="text/css">
<!--
.STYLE1 {
font-family: "新宋體";
font-size: 18px;
font-weight: bold;
}
-->
</style>
<script src="prototype.js" type="text/javascript"></script>
<script src="validation_cn.js" type="text/javascript"></script>
<link rel="stylesheet" type="text/css" href="style_min.css"/>
<script language="JavaScript" type="text/javascript">
var request = false;
try{
request = new XMLHttpRequest();
}catch(microsoftIE){
try{
request = new ActiveXObject("Msxml2.XMLHTTP");
}catch(microsoftOldIE){
try{
request = new ActiveXObject("Microsoft.XMLHTTP");
}catch(failed){
request = false;
}
}
}
if(!request){
alert("初始化XMLHttpRequest對象失敗");
}
function sendUsername(){
var username = document.getElementById("username").value;
if(username!=null && username!=""){
var url = "/MeetingAction.do?mode=isexist&username="+escape(username);
request.open("get",url,true);
request.onreadystatechange=updatepage;
request.send(null);
}
}
function updatepage(){
if(request.readyState==4){
if(request.status==200){
document.getElementById("reusername").innerHTML = request.responseText;
//document.getDocumentById("reusername").innerText = request.responseText;
}else if(request.status==404){
alert("找不到頁面!");
}else{
alert("錯誤代碼:"+request.status);
}
}
}
function clearMessage(){
document.getElementById("reusername").innerHTML = "";
}
</script>
</head>
<body>
<form id="form1" name="form1" method="post" action="/MeetingAction.do?mode=insertuser">
<div align="center">
<p class="STYLE1">新用戶注冊</p>
<table width="339" height="197" border="1" bgcolor="#FFCCFF">
<tr>
<td>用戶名 <input type="text" name="username"
onblur="sendUsername()" onfocus="clearMessage()" /></td>
<td width="40%" id="reusername"></td>
</tr>
<tr>
<td>密 碼 <input type="password" class='required equals-$otherInputId' name="password1" /> </td>
</tr>
<tr>
<td>確 認 <input type="password" class='required equals-$otherInputId' name="password2" /> </td>
</tr>
<tr>
<td height="34">郵 箱 <input type="text" class='required validate-email'
name="email" /></td>
</tr>
<tr>
<td>
<div align="center"><input type="submit" name="Submit"
value="提交" /></div>
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
在index.jsp中 var url = "/MeetingAction.do?mode=isexist&username="+escape(username);
這個請求URL是查詢用戶輸入的用戶名在數據庫里面是否存在;
在action里面這樣
String username = request.getParameter("username");//從index.jsp里面得到用戶輸入的用戶名
Boolean exist = this.getIMeetingService().isExist(username);//執行SQL語句
request.setAttribute("exist", exist);
SQL語句為select count(*) from userinf where username in(?)
exist.jsp
<%@ page language="java" pageEncoding="UTF-8"%>
<link rel="stylesheet" type="text/css" href="style_min.css"/>
<%
Boolean exist = (Boolean)request.getAttribute("exist");
//System.out.println("username:"+username);
if(exist){
out.println("<font color='red'>用戶名已經注冊</font>");
}else{
out.println("<font color='green'>用戶名可以用</font>");
}
%>
通過action處理后返回到exist.jsp來展現具體內容。
環境
eclipse3.2
tomcat6.0
jdk1.5
下面簡單介紹下關于Ajax的主要實現部分
































































































在index.jsp中 var url = "/MeetingAction.do?mode=isexist&username="+escape(username);
這個請求URL是查詢用戶輸入的用戶名在數據庫里面是否存在;
在action里面這樣



SQL語句為select count(*) from userinf where username in(?)
exist.jsp











通過action處理后返回到exist.jsp來展現具體內容。