Ajax局部刷新在之前的文章中也有介紹過，下面以一個登錄的例子為大家介紹下其具體的使用
二話不說了，直接給代碼，相信需要的都是代碼而不是廢話一堆…… 1.java代碼： 代碼如下: 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>" + "對不起,'yangjinde'此名已經注冊" + "</content>"); } else { out.println("<content>" + "可以注冊哦" + "</content>"); } out.println("</pront>"); out.close(); } } 2.jsp代碼： 代碼如下: <%@ 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> //設一個變量 var XMLHttpReq=false; //創建一個XMLHttpRequest對象 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){} } } } //發送請求函數 function send(url){ createXMLHttpRequest(); XMLHttpReq.open("GET",url,true); XMLHttpReq.onreadystatechange=proce; //指定響應的函數 XMLHttpReq.send(null); //發送請求 } function proce(){ if(XMLHttpReq.readyState==4){ //對象狀態 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，所請求的頁面有異常"); } } } //身份驗證 function check(){ var name=document.getElementById("name").value; if(name==""){ alert("請輸入內容哦"); 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="點我試試看" onClick="check()"/> </td> </tr> <tr><td><div id="data">等下我會變哦！！</div></td></tr> </form> </body> </html> 3.xml配置文件代碼： 復制代碼 代碼如下: <?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/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>
