Ajax局部刷新在之前的文章中也有介绍过，下面以一个登录的例子为大家介绍下其具体的使用
二话不说了，直接给代码，相信需要的都是代码而不是废话一堆……1.java代码：代码如下:package tt;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;public class TestA extends HttpServlet {private static final long serialVersionUID = -7999241892841130740L;protected void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException {request.setCharacterEncoding("utf-8");String name = request.getParameter("name");response.setContentType("text/xml; charset=utf-8");response.setHeader("Cache-Control", "no-cache");PrintWriter out = response.getWriter();out.println("<pront>");if (name.equals("yangjinde")) {out.println("<content>" + "对不起,'yangjinde'此名已经注册" + "</content>");} else {out.println("<content>" + "可以注册哦" + "</content>");}out.println("</pront>");out.close();}}2.jsp代码：代码如下:<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%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%>"><title>My JSP 'index.jsp' starting page</title><meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0"><meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="This is my page"><script>//设一个变量var XMLHttpReq=false;//创建一个XMLHttpRequest对象function createXMLHttpRequest(){if(window.XMLHttpRequest){ //MozillaXMLHttpReq=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 res=XMLHttpReq.responseXML.getElementsByTagName("content")[0].firstChild.data;window.alert(res);document.getElementById("data").innerHTML = res;document.getElementById("name").value = res;}else{window.alert("不好意思，所请求的页面有异常");}}}//身份验证function check(){var name=document.getElementById("name").value;if(name==""){alert("请输入内容哦");return false;}else{send('login?name='+name);}}</script></head><body><form action="login" method="post"><tr><td>姓名: <input id="name" type="text" name="name"/><input type="button" value="点我试试看" onClick="check()"/></td></tr><tr><td><div id="data">等下我会变哦！！</div></td></tr></form></body></html>3.xml配置文件代码：复制代码 代码如下:<?xml version="1.0" encoding="UTF-8"?><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/j2eehttp://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"><servlet><servlet-name>login</servlet-name><servlet-class>tt.TestA</servlet-class></servlet><servlet-mapping><servlet-name>login</servlet-name><url-pattern>/login</url-pattern></servlet-mapping><welcome-file-list><welcome-file>index.jsp</welcome-file></welcome-file-list></web-app>
