Ajax局部刷新應(yīng)用案例---簡(jiǎn)單登錄

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>" + "對(duì)不起,'yangjinde'此名已經(jīng)注冊(cè)" + "/content>");
} else {
out.println("content>" + "可以注冊(cè)哦" + "/content>");
}
out.println("/pront>");
out.close();
}
}

%@ 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>
//設(shè)一個(gè)變量
var XMLHttpReq=false;
//創(chuàng)建一個(gè)XMLHttpRequest對(duì)象
function createXMLHttpRequest(){
if(window.XMLHttpRequest){ //Mozilla
XMLHttpReq=new XMLHttpRequest();
}
else if(window.ActiveXObject){
try{
XMLHttpReq=new ActiveXObject("Msxml2.XMLHTTP");
}catch(e){
try{
XMLHttpReq=new ActiveXObject("Microsoft.XMLHTTP");
}catch(e){}
}
}
}
//發(fā)送請(qǐng)求函數(shù)
function send(url){
createXMLHttpRequest();
XMLHttpReq.open("GET",url,true);
XMLHttpReq.onreadystatechange=proce; //指定響應(yīng)的函數(shù)
XMLHttpReq.send(null); //發(fā)送請(qǐng)求
}
function proce(){
if(XMLHttpReq.readyState==4){ //對(duì)象狀態(tài)
if(XMLHttpReq.status==200){//信息已成功返回，開始處理信息
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，所請(qǐng)求的頁面有異常");
}
}
}
//身份驗(yàn)證
function check(){
var name=document.getElementById("name").value;
if(name==""){
alert("請(qǐng)輸入內(nèi)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="點(diǎn)我試試看" onClick="check()"/>
/td>
/tr>
tr>td>div id="data">等下我會(huì)變哦??！/div>/td>/tr>
/form>
/body>
/html>

?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/j2ee
http://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>