AJAX范例入门 _Ajax

AJAX实例入门

一、开门见山

??? 这些时间，瞎子也看得见，AJAX正大踏步的朝我们走来。不管我们是拥护也好，反对也罢，还是视而不见，AJAX像一阵潮流，席转了我们所有的人。
??? 关于AJAX的定义也好，大话也好，早有人在网上发表了汗牛充栋的文字，在这里我也不想照本宣科。
??? 只想说说我感觉到的一些优点，对于不对，大家也可以和我讨论：
??? 首先是异步交互，用户感觉不到页面的提交，当然也不等待页面返回。这是使用了AJAX技术的页面给用户的第一感觉。
??? 其次是响应速度快，这也是用户强烈体验。
??? 然后是与我们开发者相关的，复杂UI的成功处理，一直以来，我们对B/S模式的UI不如C/S模式UI丰富而苦恼。现在由于AJAX大量使用JS，使得复杂的UI的设计变得更加成功。
??? 最后，AJAX请求的返回对象为XML文件，这也是一个潮流，就是WEB SERVICE潮流一样。易于和WEB SERVICE结合起来。
?? ?好了，闲话少说，让我们转入正题吧。
??? 我们的第一个例子是基于Servlet为后台的一个web应用。
?
?
二、基于Servlet的AJAX

?? ?第一个例子是关于关联选择框的问题，如图：
?
??? 这是一个很常见的UI，当用户在第一个选择框里选择ZHEJIANG时，第二个选择框要出现ZHEJIANG的城市；当用户在第一个选择框里选择JIANGSU时，第二个选择框里要出现JIANGSU的城市。
??? 首先，我们来看配置文件web.xml，在里面配置一个servlet，跟往常一样：
?<web-app version="2.4"
?xmlns="http://java.sun.com/xml/ns/j2ee"
?xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
?xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
?http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
?
?<servlet>
?<servlet-name>SelectCityServlet</servlet-name>
?<servlet-class>com.stephen.servlet.SelectCityServlet</servlet-class>
?</servlet>
?
?<servlet-mapping>
?<servlet-name>SelectCityServlet</servlet-name>
?<url-pattern>/servlet/SelectCityServlet</url-pattern>
?</servlet-mapping>
?
?</web-app>
?
??? 然后，来看我们的JSP文件：
?<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
?<html>
?<head>
?<title>MyHtml.html</title>
?
?<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
?<meta http-equiv="description" content="this is my page">
?
?
?
?</head>
?<script type="text/javascript">
?function getResult(stateVal) {
???????? var url = "servlet/SelectCityServlet?state="+stateVal;
???????? if (window.XMLHttpRequest) {
???????????????? req = new XMLHttpRequest();
???????? }else if (window.ActiveXObject) {
???????????????? req = new ActiveXObject("Microsoft.XMLHTTP");
???????? }
???????? if(req){
???????????????? req.open("GET",url, true);
???????????????? req.onreadystatechange = complete;
???????????????? req.send(null);
???????? }
?}
?function complete(){
???????? if (req.readyState == 4) {
???????????????? if (req.status == 200) {
???????????????????????? var city = req.responseXML.getElementsByTagName("city");
???????????????????????? //alert(city.length);
???????????????????????? var str=new Array();
???????????????????????? for(var i=0;i<city.length;i++){
???????????????????????????????? str[i]=city[i].firstChild.data;
???????????????????????? }
???????????????????????? //alert(document.getElementById("city"));
???????????????????????? buildSelect(str,document.getElementById("city"));
???????????????? }
???????? }
?}
?function buildSelect(str,sel) {
???????? sel.options.length=0;
???????? for(var i=0;i<str.length;i++) {
???????????????? sel.options[sel.options.length]=new Option(str[i],str[i])
???????? }
?}
?</script>
?<body>
?<select name="state" onChange="getResult(this.value)">
???????? <option value="">Select</option>>
???????? <option value="zj">ZEHJIANG</option>>
???????? <option value="zs">JIANGSU</option>>
?</select>
?<select id="city">
?????<option value="">CITY</option>
?</select>
?</body>
?</html>
?
??? 第一眼看来，跟我们平常的JSP没有两样。仔细一看，不同在JS里头。
??? 我们首先来看第一个方法：getResult(stateVal)，在这个方法里，首先是取得XmlHttpRequest；然后设置该请求的url：req.open("GET",url, true);接着设置请求返回值的接收方法：req.onreadystatechange = complete;该返回值的接收方法为――complete();最后是发送请求：req.send(null);
??? 然后我们来看我们的返回值接收方法：complete()，这这个方法里，首先判断是否正确返回，如果正确返回，用DOM对返回的XML文件进行解析。关于DOM的使用，这里不再讲述，请大家参阅相关文档。得到city的值以后，再通过buildSelect(str,sel)方法赋值到相应的选择框里头去。
?
??? 最后我们来看看Servlet文件：
?import java.io.IOException;
?import java.io.PrintWriter;
?
?import javax.servlet.ServletException;
?import javax.servlet.http.HttpServlet;
?import javax.servlet.http.HttpServletRequest;
?import javax.servlet.http.HttpServletResponse;
?
?/**
? * @author Administrator
? *
? * TODO To change the template for this generated type comment go to
? * Window - Preferences - Java - Code Style - Code Templates
? */
?public class SelectCityServlet extends HttpServlet {
?
?
???? public SelectCityServlet() {
???????????? super();
???? }
?
???? public void destroy() {
???????????? super.destroy();
???? }
?
???? public void doGet(HttpServletRequest request, HttpServletResponse response)
???????????????????? throws ServletException, IOException {
???????????? response.setContentType("text/xml");
???????????? response.setHeader("Cache-Control", "no-cache");
???????????? String state = request.getParameter("state");
???????????? StringBuffer sb=new StringBuffer("<state>");
???????????? if ("zj".equals(state)){
???????????????????? sb.append("<city>hangzhou</city><city>huzhou</city>");
???????????? } else if("zs".equals(state)){
???????????????????? sb.append("<city>nanjing</city><city>yangzhou</city><city>suzhou</city>");
???????????? }
???????????? sb.append("</state>");
???????????? PrintWriter out=response.getWriter();
???????????? out.write(sb.toString());
???????????? out.close();
???? }
?}
??? 这个类也十分简单，首先是从request里取得state参数，然后根据state参数生成相应的XML文件，最后将XML文件输出到PrintWriter对象里。
??? 到现在为止，第一个例子的代码已经全部结束。是不是比较简单？我们进入到第二个实例吧！
??? 这次是基于JSP的AJAX的一个应用。
?
?
?
?
三、基于JSP的AJAX

?? 这个例子是关于输入校验的问题，我们知道，在申请用户的时候，需要去数据库对该用户性进行唯一性确认，然后才能继续往下申请。如图：
?
??? 这种校验需要访问后台数据库，但又不希望用户在这里提交后等待，当然是AJAX技术大显身手的时候了。
??? 首先来看显示UI的JSP:
?<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
?<html>
?<head>
?<title>Check.html</title>
?
?<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
?<meta http-equiv="description" content="this is my page">
?
?
?
?</head>
?<script type="text/javascript">
??var http_request = false;
? function send_request(url) {//初始化、指定处理函数、发送请求的函数
?? http_request = false;
?? //开始初始化XMLHttpRequest对象
?? if(window.XMLHttpRequest) { //Mozilla 浏览器
??? http_request = new XMLHttpRequest();
??? if (http_request.overrideMimeType) {//设置MiME类别
???? http_request.overrideMimeType('text/xml');
??? }
?? }
?? else if (window.ActiveXObject) { // IE浏览器
??? try {
???? http_request = new ActiveXObject("Msxml2.XMLHTTP");
??? } catch (e) {
???? try {
????? http_request = new ActiveXObject("Microsoft.XMLHTTP");
???? } catch (e) {}
??? }
?? }
?? if (!http_request) { // 异常，创建对象实例失败
??? window.alert("不能创建XMLHttpRequest对象实例.");
??? return false;
?? }
?? http_request.onreadystatechange = processRequest;
?? // 确定发送请求的方式和URL以及是否同步执行下段代码
?? http_request.open("GET", url, true);
?? http_request.send(null);
? }
? // 处理返回信息的函数
???? function processRequest() {
???????? if (http_request.readyState == 4) { // 判断对象状态
???????????? if (http_request.status == 200) { // 信息已经成功返回，开始处理信息
???????????????? alert(http_request.responseText);
???????????? } else { //页面不正常
???????????????? alert("您所请求的页面有异常。");
???????????? }
???????? }
???? }
? function userCheck() {
?? var f = document.form1;
?? var username = f.username.value;
?? if(username=="") {
??? window.alert("The user name can not be null!");
??? f.username.focus();
??? return false;
?? }
?? else {
??? send_request('check1.jsp?username='+username);
?? }
? }
?
?</script>
?<body>
??<form name="form1" action="" method="post">
?User Name:<input type="text" name="username" value=""> 
?<input type="button" name="check" value="check" onClick="userCheck()">
?<input type="submit" name="submit" value="submit">
?</form>
?</body>
?</html>
?
??? 所有的JS都跟上一个例子一样，不同的只是对返回值的操作，这次是用alert来显示：alert(http_request.responseText);
??? 我们来看处理逻辑JSP:
?<%@ page contentType="text/html; charset=gb2312" language="java" errorPage="" %>
?<%
?String username= request.getParameter("username");
?if("educhina".equals(username)) out.print("用户名已经被注册，请更换一个用户名。");
?else out.print("用户名尚未被使用，您可以继续。");
?%>
?
??? 非常简单，先取得参数，然后作处理，最后将结果打印在out里。
??? 我们的第三个例子仍然以这个唯一性校验为例子，这次结合Struts开发框架来完成AJAX的开发。
?
?
四、基于Struts的AJAX

??? 首先，我们仍然是对Struts应用来做配置，仍然是在struts-config,xml文件里做配置，如下：
?<action type="com.ajax.CheckAction"
???? ? scope="request" path="/ajax/check">
?????? <forward name="success" path="/check.jsp"/>
?</action>
?
??? 跟普通的Struts应用的配置一样，只是没有ActionForm的配置。
??? 下面是Action类：
?package com.ajax;
?
?import java.io.PrintWriter;
?
?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 org.apache.struts.action.DynaActionForm;
?
?/**
? * @author Administrator
? *
? * TODO To change the template for this generated type comment go to
? * Window - Preferences - Java - Code Style - Code Templates
? */
?public class CheckAction extends Action
?{
??public final ActionForward execute(ActionMapping mapping, ActionForm form,
???????????? HttpServletRequest request,
???????????? HttpServletResponse response)
???throws Exception
???{
????System.out.println("haha...............................");
????String username= request.getParameter("username");
????System.out.println(username);
????String retn;
????if("educhina".equals(username)) retn = "Can't use the same name with the old use,pls select a difference...";
????else retn = "congraducation!you can use this name....";
????PrintWriter out=response.getWriter();
???????????? out.write(retn);
???????????? out.close();
????return mapping.findForward("success");
???}
??public static void main(String[] args)
??{
??}
?}
?
??? 我们可以看到里面的逻辑跟上例中Servlet里的逻辑一样。最后，我们来看看JSP:
?<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
?<html>
?<head>
?<title>Check.html</title>
?
?<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
?<meta http-equiv="description" content="this is my page">
?
?
?
?</head>
?<script type="text/javascript">
??var http_request = false;
? function send_request(url) {//初始化、指定处理函数、发送请求的函数
?? http_request = false;
?? //开始初始化XMLHttpRequest对象
?? if(window.XMLHttpRequest) { //Mozilla 浏览器
??? http_request = new XMLHttpRequest();
??? if (http_request.overrideMimeType) {//设置MiME类别
???? http_request.overrideMimeType('text/xml');
??? }
?? }
?? else if (window.ActiveXObject) { // IE浏览器
??? try {
???? http_request = new ActiveXObject("Msxml2.XMLHTTP");
??? } catch (e) {
???? try {
????? http_request = new ActiveXObject("Microsoft.XMLHTTP");
???? } catch (e) {}
??? }
?? }
?? if (!http_request) { // 异常，创建对象实例失败
??? window.alert("不能创建XMLHttpRequest对象实例.");
??? return false;
?? }
?? http_request.onreadystatechange = processRequest;
?? // 确定发送请求的方式和URL以及是否同步执行下段代码
?? http_request.open("GET", url, true);
?? http_request.send(null);
? }
? // 处理返回信息的函数
???? function processRequest() {
???????? if (http_request.readyState == 4) { // 判断对象状态
???????????? if (http_request.status == 200) { // 信息已经成功返回，开始处理信息
???????????????? alert(http_request.responseText);
???????????? } else { //页面不正常
???????????????? alert("您所请求的页面有异常。");
???????????? }
???????? }
???? }
? function userCheck() {
?? var f = document.forms[0];
?? var username = f.username.value;
?? if(username=="") {
??? window.alert("The user name can not be null!");
??? f.username.focus();
??? return false;
?? }
?? else {
??? send_request('ajax/check.do?username='+username);
?? }
? }
?
?</script>
?<body>
??<form name="form1" action="" method="post">
?User Name:<input type="text" name="username" value=""> 
?<input type="button" name="check" value="check" onClick="userCheck()">
?<input type="submit" name="submit" value="submit">
?</form>
?</body>
?</html>
?
??? 我们可以看到，JSP基本是一样的，除了要发送的url：ajax/check.do?username='+username。
??? 最后，我们来看一个基于Struts和AJAX的复杂一些的例子，如果不用AJAX技术，UI的代码将十分复杂。
?
?
?
五、一个复杂的实例

??? 我们先来看看UI图：
?
?
?? ?这是一个比较复杂的级联：一共八个列表框，三个下拉框。从第一个列表框里选择到第二个列表框里后，第一个选择框里的选项是第二个列表框的选择；然后，在第一个选择框里选择以后，与选择值关联的一些选项出现在第三个列表框里。从第三个列表框里选择选项到第四个列表框里，同样，第二个选择框的选项也是第四个列表框的选项；如果对第二个选择框进行选择后，与选择值关联的一些选项出现在第六个列表框里，依次类推……
??? 这个UI的逻辑就比较复杂，但使用了AJAX使得我们实现起来就简单多了，这个例子我们除了使用Action类，还要用到POJO类和Business类，然后我们扩展的话，可以通过Business类和数据库连接起来。
??? 我们还是先看配置文件：
?<action type="com.ajax.SelectAction"
???? ? scope="request" path="/ajax/select">
?????? <forward name="success" path="/select.jsp"/>
?</action>
?
??? 然后看看Action类：
?/*
?/**
? * Title : Base Dict Class
? * Description : here Description is the function of class, here maybe multirows
? * Copyright: Copyright (c) 2004
? * @company Freeborders Co., Ltd.
? * @Goal Feng????????
? * @Version?????? 1.0
? */
?
?package com.ajax;
?
?import java.io.PrintWriter;
?import java.util.List;
?
?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;
?
?/**
? * @author Administrator
? *
? * TODO To change the template for this generated type comment go to
? * Window - Preferences - Java - Code Style - Code Templates
? */
?public class SelectAction extends Action
?{
??public final ActionForward execute(ActionMapping mapping, ActionForm form,
???????????? HttpServletRequest request,
???????????? HttpServletResponse response)
???throws Exception
???{
????response.setContentType("text/xml");
????????? response.setHeader("Cache-Control", "no-cache");
????????? String type = request.getParameter("type");
????????? String id = request.getParameter("id");
????????? System.out.println(id);
????????? StringBuffer sb=new StringBuffer("<select>");
????????? sb.append("<type>"+type+"</type>");
?????????
????????? List list = new SelectBusiness().getData(id);
????????? for(int i=0;i<list.size();i++)
????????? {
????????? ?SelectForm sel = (SelectForm)list.get(i);
????????? ?sb.append("<text>"+sel.getText()+"</text><value>"+sel.getValue()+"</value>");
????????? }
??
????????? sb.append("</select>");
????????? PrintWriter out=response.getWriter();
????????? out.write(sb.toString());
????????? out.close();
????????? System.out.println(sb.toString());
????return mapping.findForward("success");
???}
??public static void main(String[] args)
??{
??}
?}
?
??? POJO类和Business类：
?package com.ajax;
?/**
? * @author Administrator
? *
? * TODO To change the template for this generated type comment go to
? * Window - Preferences - Java - Code Style - Code Templates
? */
?public class SelectForm
?{
??private String text;
??private String value;
?
??/**
?? * @return Returns the text.
?? */
??public String getText()
??{
???return text;
??}
??/**
?? * @param text The text to set.
?? */
??public void setText(String text)
??{
???this.text = text;
??}
??/**
?? * @return Returns the value.
?? */
??public String getValue()
??{
???return value;
??}
??/**
?? * @param value The value to set.
?? */
??public void setValue(String value)
??{
???this.value = value;
??}
??public static void main(String[] args)
??{
??}
?}
?
?
?package com.ajax;
?
?import java.util.ArrayList;
?import java.util.List;
?
?/**
? * @author Administrator
? *
? * TODO To change the template for this generated type comment go to
? * Window - Preferences - Java - Code Style - Code Templates
? */
?public class SelectBusiness
?{
??public List getData(String id)
??{
???ArrayList list = new ArrayList();
???for(int i=1;i<6;i++)
???{
????SelectForm form = new SelectForm();
????form.setText(id+i);
????form.setValue(id+i);
????list.add(form);
???}
???return list;
??}
?
??public static void main(String[] args)
??{
??}
?}
?
??? 最后是JSP文件：
?<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
?<HTML>
?<HEAD>
?<TITLE>FB</TITLE>
?<LINK href="images/magazin.css" type=text/css rel=stylesheet>
?<LINK href="images/briefing.css" type=text/css rel=stylesheet>
?<META http-equiv=Content-Type content="text/html; charset=utf-8">
?<META content="MSHTML 6.00.2800.1498" name=GENERATOR>
?<style type="text/css">
?
?</style>
?<script language="javascript">
?function Add()
?{
?if(document.all.Education2.style.display=='block')document.all.Education2.style.display='none';
?else document.all.Education2.style.display='block';
?}
?</script>
?</HEAD>
?<BODY leftMargin=0 topMargin=0 marginheight="0" marginwidth="0">
?<script type="text/javascript" src="images/head.js"></script>
?<script language=javascript>
?
?function getResult(type,id) {
???????? var url = "ajax/select.do?type="+type+"&id="+id;
???????? if (window.XMLHttpRequest) {
???????????????? req = new XMLHttpRequest();
???????? }else if (window.ActiveXObject) {
???????????????? req = new ActiveXObject("Microsoft.XMLHTTP");
???????? }
???????? if(req){
???????????????? req.open("GET",url, true);
???????????????? req.onreadystatechange = complete;
???????????????? req.send(null);
???????? }
?}
?function complete(){
???????? if (req.readyState == 4) {
???????????????? if (req.status == 200) {
???????????????????????? var type = req.responseXML.getElementsByTagName("type");
???????????????????????? ?var value = req.responseXML.getElementsByTagName("value");
???????????????????????? ?var str=new Array();
???????????????????????? ?for(var i=0;i<value.length;i++){
??????????????????????????????? str[i]=value[i].firstChild.data;
???????????????????????????? }
???????????????????????? var type = type[0].firstChild.data;
????????????????????????
???????????????????????? removeType1(type);
????????????????????????????
??????????????????????? if(type=="0")
???????????????????????? {
???????????????????????? ?
???????????????????????? ?buildSelect(str,document.getElementById("select28"));
??????????????????????? }
??????????????????????? else if(type=="1")
??????????????????????? {
??????????????????????? ??buildSelect(str,document.getElementById("select32"));
??????????????????????? }
??????????????????????? else if(type=="2")
??????????????????????? {
??????????????????????? ??buildSelect(str,document.getElementById("select34"));
??????????????????????? }
???????????????????????
???????????????? }
???????? }
?}
?function buildSelect(str,sel) {
???????? sel.options.length=0;
???????? for(var i=0;i<str.length;i++) {
???????????????? sel.options[sel.options.length]=new Option(str[i],str[i])
???????? }
?}
????????
????????
?
??function removeType1(type)
???{
????var form = document.forms[0];
????if(type=="0")
????{
?????removeAll(form.select28);
?????removeAll(form.select29);
?????removeAll(form.select30);
?????removeAll(form.select31);
?????removeAll(form.select32);
?????removeAll(form.select33);
?????removeAll(form.select34);
?????removeAll(form.select35);
????}
????else if(type=="1")
????{
?????removeAll(form.select31);
?????removeAll(form.select32);
?????removeAll(form.select33);
?????removeAll(form.select34);
?????removeAll(form.select35);
????}
????else if(type=="2")
????{
?????removeAll(form.select34);
?????removeAll(form.select35);
????}
????else if(type=="3")
????{
?????
????}
???}
??
??
???
??? function selChange(f,h)
???{
????for(i = 0;i < f.length; i++)
????{??
?????if(f.options[i].selected == true)
?????{ ???
??????h.options.add(new Option( f.options[i].text,f.options[i].value));
??????f.options.remove(i);
??????i--;
?????}
????}
???}
???
???function removeAll(obj)
???{
????for(i=0;i<obj.length;i++)
????{
?????obj.options.remove(i);
?????i--;
????}
???}
???
???function addAll(f,h)
???{?
????for(i = 0;i < f.length; i++)
????{
?????h.options.add(new Option( f.options[i].text,f.options[i].value));
?????f.options.remove(i);
?????i--;?
????}
???}
???
???function changeSel(offer,getter,type)
???{
????removeType(type);
????for(i=0;i<getter.length;i++)
????{
?????getter.options.remove(i);
?????i--;
????}
????getter.options.add(new Option("",""));
????for(i = 0;i < offer.length; i++)
????{
?????getter.options.add(new Option(offer.options[i].text,offer.options[i].value));
????}
???}
???
???function removeType(type)
???{
????var form = document.forms[0];
????if(type=="0")
????{
?????removeAll(form.select25);
?????removeAll(form.select28);
?????removeAll(form.select29);
?????removeAll(form.select30);
?????removeAll(form.select31);
?????removeAll(form.select32);
?????removeAll(form.select33);
?????removeAll(form.select34);
?????removeAll(form.select35);
????}
????else if(type=="1")
????{
?????removeAll(form.select30);
?????removeAll(form.select31);
?????removeAll(form.select32);
?????removeAll(form.select33);
?????removeAll(form.select34);
?????removeAll(form.select35);
????}
????else if(type=="2")
????{
?????removeAll(form.select31);
?????removeAll(form.select34);
?????removeAll(form.select35);
????}
????else if(type=="3")
????{
?????
????}
???}
???function removeAll(obj)
???{
????for(i=0;i<obj.length;i++)
????{
?????obj.options.remove(i);
?????i--;
????}
???}
??
????</script>
?<form>
?<font face="Arial, Helvetica, sans-serif"></font>
?<TABLE cellSpacing=0 cellPadding=0 width="100%" border=0>
?? <TBODY>
?? <TR>
???? <TD align=middle vAlign=top bgcolor="#eeeeee">
???????? <TABLE cellSpacing=0 cellPadding=0 width=945 align=center
?????? background=images/bg2.gif border=0>
?????????? <TBODY>
???????????? <TR>
?????????????? <TD vAlign=top> <TABLE cellSpacing=0 cellPadding=0 width="95%" align=center border=0>
?????????????????? <TBODY>
???????????????????? <TR>
?????????????????????? <TD width="97%" align=right> <p align="left"> Resource Management >> New
?????????????????????????? Staff</TD>
???????????????????? </TR>
???????????????????? <TR height=4>
?????????????????????? <TD></TD>
???????????????????? </TR>
???????????????????? <TR>
?????????????????????? <TD valign="top"> <table class=homeBody cellspacing=0 cellpadding=0 width="100%"
?align=center border=0>
?????????????????????????? <tbody>
???????????????????????????? <tr>
?????????????????????????????? <td height=25 colspan="2" nowrap><table class=grid style="WIDTH: 100%;" cellspacing=0 cellpadding=3>
?????????????????????????????????? <tbody>
???????????????????????????????????? <tr class=gridHeader>
?????????????????????????????????????? <td width="26%" align=left bgcolor="#eeeeee" ><strong> Personal
???????????????????????????????????????? Information</strong></td>
?????????????????????????????????????? <td width="74%" align=left bgcolor="#eeeeee" ><span class="gridAlternating">Last
???????????????????????????????????????? Modified : 06/06/2005</span></td>
???????????????????????????????????? </tr>
?????????????????????????????????? </tbody>
???????????????????????????????? </table></td>
???????????????????????????? </tr>
???????????????????????????? <tr>
?????????????????????????????? <td valign=middle nowrap><div align="right"><input style="width:50px" class="button" type="button" value="Save"
????????? name="B323252">  <input style="width:50px" class="button" type="button" value="Undo" name="B323262">
???????????????????????????????? </div></td>
???????????????????????????? </tr>
???????????????????????????? <tr>
?????????????????????????????? <td colspan=2 valign="top" class="modifiedRow modifiedProducts">
???????????????????????????????? <table id=DynamicTabsTable cellspacing=0 cellpadding=0
?border=0 name="DynamicTabsTable">
?????????????????????????????????? <tbody>
???????????????????????????????????? <tr id=DynamicTabsTR>
?????????????????????????????????????? <script language=JavaScript
?src="images/Public.js"></script>
???????????????????????????????????? </tr>
?????????????????????????????????? </tbody>
???????????????????????????????? </table>
???????????????????????????????? <table width="100%" border="0" cellpadding="0" cellspacing="3" bordercolorlight="#C0C0C0" bordercolordark="#FFFFFF">
??????????????????????????????????
?????????????????????????????????? <tr>
???????????????????????????????????? <td nowrap><fieldset align="left" style="PADDING-RIGHT: 8px; PADDING-LEFT: 8px; PADDING-BOTTOM: 8px; LINE-HEIGHT: 30px; PADDING-TOP: 8px;width:900px">
?????????????????????????????????????? <legend class=legend>Freeborders Experience</legend>
?????????????????????????????????????? <table width="100%" height="15" border="0" align="center" cellspacing="0" bordercolorlight="#C0C0C0" bordercolordark="#FFFFFF" id="table21">
???????????????????????????????????????? <tr>
?????????????????????????????????????????? <td nowrap><strong>FB Vertical Experience</strong></td>
?????????????????????????????????????????? <td colspan="2"><strong>FB Customer
???????????????????????????????????????????? Experience </strong></td>
???????????????????????????????????????? </tr>
???????????????????????????????????????? <tr>
?????????????????????????????????????????? <td height="26" valign="top" nowrap> </td>
?????????????????????????????????????????? <td colspan="2" valign="top" nowrap><strong>
???????????????????????????????????????????? <select name="select25" id="select25" style="WIDTH: 179px" onchange="getResult('0',document.forms[0].select25.value);">
?????????????????????????????????????????????? <option value="b">b</option>
?????????????????????????????????????????????? <option value="c">c</option>
???????????????????????????????????????????? </select>
???????????????????????????????????????????? </strong></td>
???????????????????????????????????????? </tr>
???????????????????????????????????????? <tr>
?????????????????????????????????????????? <td height="26" valign="top" nowrap>
???????????????????????????????????????????? <table? border="0" cellspacing="0" cellpadding="0" id="table34">
?????????????????????????????????????????????? <tr>
???????????????????????????????????????????????? <td> <select id="select26" style="WIDTH: 180px; HEIGHT: 120px" multiple="multiple" size="4" name="select26">
???????????????????????????????????????????????????? <option value="a">a</option>
?????????????????????????????????????????????????? </select>
???????????????????????????????????????????????? </td>
???????????????????????????????????????????????? <td width="50" align="middle" valign="middle" bordercolorlight="#C0C0C0" bordercolordark="#FFFFFF" class="tableblackborder"><div align="center">
???????????????????????????????????????????????????? <table width="80%" height="110" border="0" align="center" cellpadding="0" cellspacing="0" id="table35">
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td><div align="center">
???????????????????????????????????????????????????????????? <input name="button2" type="button" class="button" id="button29" style="WIDTH: 30px"? value=">" onclick="selChange(document.forms[0].select26,document.forms[0].select27);changeSel(document.forms[0].select27,document.forms[0].select25,'0')" />
?????????????????????????????????????????????????????????? </div></td>
?????????????????????????????????????????????????????? </tr>
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td><div align="center">
???????????????????????????????????????????????????????????? <input name="button2" type="button" class="button" id="button30" style="WIDTH: 30px" value=">>" causesvalidation="False" onclick="addAll(document.forms[0].select26,document.forms[0].select27);changeSel(document.forms[0].select27,document.forms[0].select25,'0')"/>
?????????????????????????????????????????????????????????? </div></td>
?????????????????????????????????????????????????????? </tr>
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td height="5"><div align="center"></div></td>
?????????????????????????????????????????????????????? </tr>
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td><div align="center">
???????????????????????????????????????????????????????????? <input name="button2" type="button" class="button" id="button31" style="WIDTH: 30px" value="<" causesvalidation="False" onclick="selChange(document.forms[0].select27,document.forms[0].select26,document.forms[0].select25,1);changeSel(document.forms[0].select27,document.forms[0].select25,'0')"/>
?????????????????????????????????????????????????????????? </div></td>
?????????????????????????????????????????????????????? </tr>
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td><div align="center">
???????????????????????????????????????????????????????????? <input name="button2" type="button" class="button" id="button32" style="WIDTH: 30px" value="<<" causesvalidation="False" onclick="addAll(document.forms[0].select27,document.forms[0].select26);changeSel(document.forms[0].select27,document.forms[0].select25,'0')"/>
?????????????????????????????????????????????????????????? </div></td>
?????????????????????????????????????????????????????? </tr>
???????????????????????????????????????????????????? </table>
?????????????????????????????????????????????????? </div></td>
???????????????????????????????????????????????? <td> </td>
???????????????????????????????????????????????? <td align="right"> <select id="select27"
???????????? style="WIDTH: 180px; HEIGHT: 120px" multiple="multiple" size="4"
???????????? name="select27">
???????????????????????????????????????????????????? <option value="b">b</option>
???????????????????????????????????????????????????? <option value="c" selected>c</option>
?????????????????????????????????????????????????? </select></td>
?????????????????????????????????????????????? </tr>
???????????????????????????????????????????? </table></td>
?????????????????????????????????????????? <td colspan="2" valign="top" nowrap>
???????????????????????????????????????????? <table? border="0" cellspacing="0" cellpadding="0" id="table36">
?????????????????????????????????????????????? <tr>
???????????????????????????????????????????????? <td> <select id="select28"
???????????? style="WIDTH: 180px; HEIGHT: 120px" multiple="multiple" size="4"
???????????? name="select28">
???????????????????????????????????????????????????? <option value="b1">b1</option>
?????????????????????????????????????????????????? </select></td>
???????????????????????????????????????????????? <td width="50" align="middle" valign="middle" bordercolorlight="#C0C0C0" bordercolordark="#FFFFFF" class="tableblackborder"><div align="center">
???????????????????????????????????????????????????? <table width="80%" height="110" border="0" align="center" cellpadding="0" cellspacing="0" id="table37">
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td><div align="center">
???????????????????????????????????????????????????????????? <input type="button"? name="button2" id="button33" style="WIDTH: 30px"? value=">" onclick="selChange(document.forms[0].select28,document.forms[0].select29);changeSel(document.forms[0].select29,document.forms[0].select30,'1')"/>
?????????????????????????????????????????????????????????? </div></td>
?????????????????????????????????????????????????????? </tr>
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td><div align="center">
???????????????????????????????????????????????????????????? <input name="button2" type="button" class="button" id="button34" style="WIDTH: 30px" value=">>" causesvalidation="False" onclick="addAll(document.forms[0].select28,document.forms[0].select29);changeSel(document.forms[0].select29,document.forms[0].select30,'1')"/>
?????????????????????????????????????????????????????????? </div></td>
?????????????????????????????????????????????????????? </tr>
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td height="5"><div align="center"></div></td>
?????????????????????????????????????????????????????? </tr>
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td><div align="center">
???????????????????????????????????????????????????????????? <input name="button2" type="button" class="button" id="button35" style="WIDTH: 30px" value="<" causesvalidation="False" onclick="selChange(document.forms[0].select29,document.forms[0].select28);changeSel(document.forms[0].select29,document.forms[0].select30,'1')"/>
?????????????????????????????????????????????????????????? </div></td>
?????????????????????????????????????????????????????? </tr>
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td><div align="center">
???????????????????????????????????????????????????????????? <input name="button2" type="button" class="button" id="button36" style="WIDTH: 30px" value="<<" causesvalidation="False" onclick="addAll(document.forms[0].select29,document.forms[0].select28);changeSel(document.forms[0].select29,document.forms[0].select30,'1')"/>
?????????????????????????????????????????????????????????? </div></td>
?????????????????????????????????????????????????????? </tr>
???????????????????????????????????????????????????? </table>
?????????????????????????????????????????????????? </div></td>
???????????????????????????????????????????????? <td> </td>
???????????????????????????????????????????????? <td> <select id="select29"
???????????? style="WIDTH: 180px; HEIGHT: 120px" multiple="multiple" size="4"
???????????? name="select29">
???????????????????????????????????????????????????? <option value="b2">b2</option>
?????????????????????????????????????????????????? </select></td>
?????????????????????????????????????????????? </tr>
???????????????????????????????????????????? </table></td>
???????????????????????????????????????? </tr>
???????????????????????????????????????? <tr>
?????????????????????????????????????????? <td height="10" colspan="2" nowrap></td>
?????????????????????????????????????????? <td width="275" valign="top"> </td>
???????????????????????????????????????? </tr>
???????????????????????????????????????? <tr>
?????????????????????????????????????????? <td nowrap><strong>Project Experience</strong></td>
?????????????????????????????????????????? <td colspan="2" nowrap><strong>SubProject
???????????????????????????????????????????? Experience</strong></td>
???????????????????????????????????????? </tr>
???????????????????????????????????????? <tr>
?????????????????????????????????????????? <td height="10" valign="top" nowrap><strong>
???????????????????????????????????????????? <select name="select30" id="select30" style="WIDTH: 179px" onchange="getResult('1',document.forms[0].select30.value);">
?????????????????????????????????????????????? <option value=""></option>
?????????????????????????????????????????????? <option value="b2">b2</option>
???????????????????????????????????????????? </select>
???????????????????????????????????????????? </strong></td>
?????????????????????????????????????????? <td colspan="2" valign="top" nowrap><strong>
???????????????????????????????????????????? <select name="select31" id="select31" style="WIDTH: 179px" onchange="getResult('2',document.forms[0].select31.value);">
?????????????????????????????????????????????? <option> </option>
?????????????????????????????????????????????? <option value="b13">b13</option>
?????????????????????????????????????????????? <option value="b14">b14</option>
???????????????????????????????????????????? </select>
???????????????????????????????????????????? </strong></td>
???????????????????????????????????????? </tr>
???????????????????????????????????????? <tr>
?????????????????????????????????????????? <td height="10" valign="top" nowrap>
???????????????????????????????????????????? <table? border="0" cellspacing="0" cellpadding="0" id="table38">
?????????????????????????????????????????????? <tr>
???????????????????????????????????????????????? <td> <select id="select32"
???????????? style="WIDTH: 180px; HEIGHT: 120px" multiple="multiple" size="4"
???????????? name="select32">
???????????????????????????????????????????????????? <option value="b11">b11</option>
???????????????????????????????????????????????????? <option value="b12">b12</option>
?????????????????????????????????????????????????? </select></td>
???????????????????????????????????????????????? <td width="50" align="middle" valign="middle" bordercolorlight="#C0C0C0" bordercolordark="#FFFFFF" class="tableblackborder"><div align="center">
???????????????????????????????????????????????????? <table width="80%" height="110" border="0" align="center" cellpadding="0" cellspacing="0" id="table39">
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td><div align="center">
???????????????????????????????????????????????????????????? <input name="button2" type="button" class="button" id="button37" style="WIDTH: 30px"? value=">" onclick="selChange(document.forms[0].select32,document.forms[0].select33);changeSel(document.forms[0].select33,document.forms[0].select31,'2')"/>
?????????????????????????????????????????????????????????? </div></td>
?????????????????????????????????????????????????????? </tr>
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td><div align="center">
???????????????????????????????????????????????????????????? <input name="button2" type="button" class="button" id="button38" style="WIDTH: 30px" value=">>" causesvalidation="False" onclick="addAll(document.forms[0].select32,document.forms[0].select33);changeSel(document.forms[0].select33,document.forms[0].select31,'2')"/>
?????????????????????????????????????????????????????????? </div></td>
?????????????????????????????????????????????????????? </tr>
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td height="5"><div align="center"></div></td>
?????????????????????????????????????????????????????? </tr>
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td><div align="center">
???????????????????????????????????????????????????????????? <input name="button2" type="button" class="button" id="button39" style="WIDTH: 30px" value="<" causesvalidation="False" onclick="selChange(document.forms[0].select33,document.forms[0].select32);changeSel(document.forms[0].select33,document.forms[0].select31,'2')"/>
?????????????????????????????????????????????????????????? </div></td>
?????????????????????????????????????????????????????? </tr>
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td><div align="center">
???????????????????????????????????????????????????????????? <input name="button2" type="button" class="button" id="button40" style="WIDTH: 30px" value="<<" causesvalidation="False" onclick="addAll(document.forms[0].select33,document.forms[0].select32);changeSel(document.forms[0].select33,document.forms[0].select31,'2')"/>
?????????????????????????????????????????????????????????? </div></td>
?????????????????????????????????????????????????????? </tr>
???????????????????????????????????????????????????? </table>
?????????????????????????????????????????????????? </div></td>
???????????????????????????????????????????????? <td> </td>
???????????????????????????????????????????????? <td> <select id="select33"
???????????? style="WIDTH: 180px; HEIGHT: 120px" multiple="multiple" size="4"
???????????? name="select33">
???????????????????????????????????????????????????? <option value="b13">b13</option>
???????????????????????????????????????????????????? <option value="b14">b14</option>
?????????????????????????????????????????????????? </select></td>
?????????????????????????????????????????????? </tr>
???????????????????????????????????????????? </table></td>
?????????????????????????????????????????? <td colspan="2" valign="top" nowrap>
???????????????????????????????????????????? <table? border="0" cellspacing="0" cellpadding="0" id="table40">
?????????????????????????????????????????????? <tr>
???????????????????????????????????????????????? <td> <select id="select34"
???????????? style="WIDTH: 180px; HEIGHT: 120px" multiple="multiple" size="4"
???????????? name="select34">
???????????????????????????????????????????????????? <option value="b111">b111</option>
???????????????????????????????????????????????????? <option value="b112">b112</option>
???????????????????????????????????????????????????? <option value="b113">b113</option>
?????????????????????????????????????????????????? </select></td>
???????????????????????????????????????????????? <td width="50" align="middle" valign="middle" bordercolorlight="#C0C0C0" bordercolordark="#FFFFFF" class="tableblackborder"><div align="center">
???????????????????????????????????????????????????? <table width="80%" height="110" border="0" align="center" cellpadding="0" cellspacing="0" id="table41">
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td><div align="center">
???????????????????????????????????????????????????????????? <input name="button2" type="button" class="button" id="button41" style="WIDTH: 30px"? value=">" onclick="selChange(document.forms[0].select34,document.forms[0].select35);"/>
?????????????????????????????????????????????????????????? </div></td>
?????????????????????????????????????????????????????? </tr>
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td><div align="center">
???????????????????????????????????????????????????????????? <input name="button2" type="button" class="button" id="button42" style="WIDTH: 30px" value=">>" causesvalidation="False" onclick="addAll(document.forms[0].select34,document.forms[0].select35)"/>
?????????????????????????????????????????????????????????? </div></td>
?????????????????????????????????????????????????????? </tr>
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td height="5"><div align="center"></div></td>
?????????????????????????????????????????????????????? </tr>
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td><div align="center">
???????????????????????????????????????????????????????????? <input name="button2" type="button" class="button" id="button43" style="WIDTH: 30px" value="<" causesvalidation="False" onclick="selChange(document.forms[0].select35,document.forms[0].select34);"/>
?????????????????????????????????????????????????????????? </div></td>
?????????????????????????????????????????????????????? </tr>
?????????????????????????????????????????????????????? <tr>
???????????????????????????????????????????????????????? <td><div align="center">
???????????????????????????????????????????????????????????? <input name="button2" type="button" class="button" id="button44" style="WIDTH: 30px" value="<<" causesvalidation="False" onclick="addAll(document.forms[0].select35,document.forms[0].select34)"/>
?????????????????????????????????????????????????????????? </div></td>
?????????????????????????????????????????????????????? </tr>
???????????????????????????????????????????????????? </table>
?????????????????????????????????????????????????? </div></td>
???????????????????????????????????????????????? <td> </td>
???????????????????????????????????????????????? <td> <select id="select35"
???????????? style="WIDTH: 180px; HEIGHT: 120px" multiple="multiple" size="4"
???????????? name="select35">
???????????????????????????????????????????????????? <option value="b114">b114</option>
???????????????????????????????????????????????????? <option value="b115">b115</option>
???????????????????????????????????????????????????? <option value="b116">b116</option>
?????????????????????????????????????????????????? </select></td>
?????????????????????????????????????????????? </tr>
???????????????????????????????????????????? </table></td>
???????????????????????????????????????? </tr>
????????????????????????????????????????
???????????????????????????????????????????? </table></td>
???????????????????????????????????????? </tr>
?????????????????????????????????????? </table>
?????????????????????????????????????? </fieldset></td>
?????????????????????????????????? </tr>
???????????????????????????????? </table></td>
???????????????????????????? </tr>
?????????????????????????? </tbody>
???????????????????????? </table></TD>
???????????????????? </TR>
?????????????????? </TBODY>
???????????????? </TABLE>
???????????????? <TABLE cellSpacing=0 cellPadding=0 width="95%" align=center border=0>
?????????????????? <TBODY>
???????????????????? <TR valign="top">
?????????????????????? <TD width="97%" align="left" valign="middle"><div align="right"><input style="width:50px" class="button" type="button" value="Save"
????????? name="B32">  <input style="width:50px" class="button" type="button" value="Undo" name="B3">
???????????????????????? </div></TD>
???????????????????? </TR>
?????????????????? </TBODY>
???????????????? </TABLE>
????????????????
?????????????? </TD>
???????????? </TR>
?????????? </TBODY>
????? </TABLE>
???????? <script type="text/javascript" src="images/bottom.js"></script></TD></TR></TBODY></TABLE>
?</BODY></form></HTML>
?
?虽然这个JSP复杂多了，但是关于AJAX的代码还是跟前面的例子一样，在这里我也就不多说了，请大家自己看。
?
?
六、蛇足

??? 好了，例子都说完了。废话也就不多说了，只说一件事：AJAX好像来势汹汹，要把我们用得极其普遍、极其习惯的Struts等的MVC开发模式取代掉一样。
??? 其实，AJAX有它的优点，同样也有它的缺点。它一般用在用户不想等待返回结果的时候和复杂的UI上；其他时候，我们还是可以使用Struts等常规方法。
??? 一句话，不要为了使用AJAX而使用AJAX，而是要在适合于使用AJAX的地方使用AJAX。
?