最近,想学学ajax,所以整个入门例子 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <title>ajax.html</title> </head> <script language="javascript">... var http_request = false; var currentPos = null; var number1=0; var number2=0; 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, false); 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); document.getElementById("showData").innerHTML = http_request.responseText; } else ...{ //页面不正常 alert("您所请求的页面有异常。"); } } } function showResult() ...{ document.getElementById("showData").innerHTML = "正在读取数据..." number1=document.getElementById("number_1").value; number2=document.getElementById("number_2").value; send_request("ajax.jsp?number_1="+number1+"&number_2="+number2); }</script> <body> <input type="text" id="number_1"/>*<input type="text" id="number_2" onblur="showResult()"/>= <label id="showData"></label><br> </body></html> //ajax.jsp<%@ page language="java" import="java.util.*" pageEncoding="GB18030"%><%String number1,number2;number1=request.getParameter("number_1");number2=request.getParameter("number_2");out.println(Integer.valueOf(number1).intValue()*Integer.valueOf(number2).intValue());%>