ajax简单例子
完成的功能:
client.jsp页面文本框输入内容,触发onblur事件后调用docheck方法,由server.jsp在内容后面加上“hello”,结果显示在<div id="result"></div>
client.jsp
- <%@ page language="java" import="java.util.*" pageEncoding="GB18030"%>
- <%
- String path = request.getContextPath();
- String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
- %>
- <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
- <html>
- <head>
- <base href="<%=basePath%>">
- <script type="text/javascript" src="http://www.hxlysw.com/ajax/check.js"></script>
- </head>
- <body>
- <input id="username" type="text" onblur="doCheck()">
- <div id="result" >显示结果</div>
- </body>
- </html>
server.jsp
- <%
- String name = request.getParameter("name");
- response.getWriter().write(name + "hello");
- %>
check.js文件
- var xhr;
- function doCheck(){
- if (window.XMLHttpRequest){// code for IE7+, Firefox, Chrome, Opera, Safari
- xhr=new XMLHttpRequest();
- }
- else{// code for IE6, IE5
- xhr=new ActiveXObject("Microsoft.XMLHTTP");
- }
- var name=document.getElementById("username").value;
- var url="ajax/server.jsp?name="+name;
- xhr.onreadystatechange = callback;
- xhr.open("GET",url,true);
- xhr.send(null);
- }
- function callback(){
- if (xhr.readyState == 4 && xhr.status == 200) {
- alert(xhr.responseText);
- document.getElementById("result").innerHTML = xhr.responseText;
- }
- }