Ajax異步請求,servlet產生隨機數據,Html頁面無刷新顯示。
運行環境:jdk1.5+tomcat 5.5
一、ajaxServlet.java
package com; 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; import java.util.Random; public class ajaxServlet extends HttpServlet{
private static final String CONTENT_TYPE="text/xml; charset=gb2312"; public void init() throws ServletException{} public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{ response.setContentType(CONTENT_TYPE); response.setHeader("Cache-Control","no-cache"); response.setHeader("Pragma","no-cache"); response.setDateHeader("Expires",0); PrintWriter out=response.getWriter(); String action=request.getParameter("action"); if(("send").equals(action)){ Random random = new Random(); String AA=Integer.toString(Math.abs(random.nextInt())); String BB=Integer.toString(Math.abs(random.nextInt())); String CC=Integer.toString(Math.abs(random.nextInt())); String DD=Integer.toString(Math.abs(random.nextInt())); StringBuffer sb=new StringBuffer(); sb.append(AA); sb.append("@@@"); sb.append(BB); sb.append("@@@"); sb.append(CC); sb.append("@@@"); sb.append(DD); out.write(sb.toString()); out.close(); } }}
二、testajax.html
<html>
<head>
<title>AJAX.html</title>
</head>
<script type="text/javascript">
function getResult(){ var url = "/Tajax/AajaxServlet?action=send"; 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); } } /*分析返回的文本文檔*/ function complete(){ if (req.readyState == 4) { if (req.status == 200) { // alert(req.responseText); var strResult = unescape(req.responseText); var arrResult = strResult.split("@@@"); RemoveRow(); //刪除以前的數據. num1 = arrResult[0]; //字段num1的值 num2 = arrResult[1]; //字段num2的值 num3 = arrResult[2]; num4 = arrResult[3]; row1= tb.insertRow(); cell1 = row1.insertCell(); cell1.innerText = num1; cell2 = row1.insertCell(); cell2.innerText = num2; row2= tb.insertRow(); cell3 = row2.insertCell(); cell3.innerText = num3; cell4 = row2.insertCell(); cell4.innerText = num4; } else { alert('There was a problem with the request.'); } } } function RemoveR