A problem with AJAX.pls!
I am learning Ajax,so I find an example from web,but I came around a problem ,and can't find the error where it is.I parse the source files here,please help me to check and point the error to me ,thanks.As follows:
JSP(ajaxsel.jsp):
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>MyHtml.html</title>
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
</head>
<script type="text/javascript">
function getResult(stateVal) {
//alert(stateVal);
var url = "servlet/SelectCityServlet?state="+stateVal;
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);
}
}
function complete() {
if(req.readyState == 4) {
if(req.status == 200) {
alert("1");
var city = req.responseXML.getElementsByTagName("city");
//alert("city.length:"+city.length);
var srt = new Array();
for(var i=0;i<city.length;i++) {
srt = city.firstChild.data;
}
//alert("city:"+document.getElementById("city"));
buildSelect(str,document.getElementById("city"));
}
}
}
function buildSelect(srt,sel) {
sel.options.length = 0;
for(var i=0;i<srt.length;i++) {
sel.options[sel.options.length] = new Option(str,str);
}
}
></script>
<body>
<select name="state" onChange="getResult(document.all.state.options[document.all.state.selectedIndex].value)">
<option value="0">Select</option>
<option value="zj">zhejiang</option>
<option value="zs">jiangsu</option>
</select>
<select name="city">
<option vlaue="">CITY</option>
</select>
</body>
</html>
XML(web.xml):
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"
"http://java.sun.com/j2ee/dtds/web-app_2_2.dtd">
<web-app>
<servlet>
<servlet-name>SelectCityServlet</servlet-name>
<servlet-class>com.stephen.servlet.SelectCityServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>SelectCityServlet</servlet-name>
<url-pattern>/servlet/SelectCityServlet</url-pattern>
</servlet-mapping>
</web-app>
SERVLET(SelectCityServlet.java):
package com.stephen.servlet;
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;
/**
* @author Administrator
*
* TODO To change the template for this generated type comment go to
* Window - Preferences - Java - Code Style - Code Templates
*/
public class SelectCityServlet extends HttpServlet {
丂丂public SelectCityServlet() {
丂丂super();
丂丂}
丂丂public void destroy() {
丂丂super.destroy();
丂丂}
丂丂public void doGet(HttpServletRequest request, HttpServletResponse response)
丂丂throws ServletException, IOException {
丂丂response.setContentType("text/xml");
丂丂response.setHeader("Cache-Control", "no-cache");
丂丂String state = request.getParameter("state");
丂丂StringBuffer sb=new StringBuffer("<state>");
丂丂if ("zj".equals(state)){
丂丂sb.append("<city>hangzhou</city><city>huzhou</city>");
丂丂} else if("zs".equals(state)){
丂丂sb.append("<city>nanjing</city><city>yangzhou</city><city>suzhou</city>");
丂丂}
丂丂sb.append("</state>");
丂丂PrintWriter out=response.getWriter();
丂丂out.write(sb.toString());
丂丂out.close();
丂丂}
}
