关于JSP 和Ajax的问题 刚开始接触AJAX 碰到了个问题 下面是代码 如果取消掉f1()方法的注释就会出错
JSP页面
<%@page pageEncoding="utf-8" contentType="text/html;charset=utf-8"%>
<html>
<head>
<script src="js/prototype-1.6.0.3.js"></script>
<script>
function getXmlHttpRequest(){
var xhr = null;
if ((typeof XMLHttpRequest) != 'undefined') {
// FF
xhr = new XMLHttpRequest();
}else {
// IE
xhr = new ActiveXObject('Microsoft.XMLHttp');
}
return xhr;
}
function f1(index){
var xhr = getXmlHttpRequest();
var vv=index;
xhr.open("post", "jjll.do", true);
xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
xhr.onreadystatechange = function() {
if(xhr.readyState==4){
if(xhr.status==200){
var text=xhr.responseText;
alert(text);
$('d1').innerHTML = text;
}else{
// $('d1').innerHTML="系统错误"；
}
}else{
// $('d1').innerHTML="正在读取"；
}
};
xhr.send("km="+vv);
}
</script>
</head>
<body>
<select id="s1" name="s1" onchange="f1(this.value);">
<option value="-1">
--专业--
</option>
<option value="english">
英语
</option>
<option value="computer">
计算机
</option>
</select>
<select id="s2" name="s2">
<option value="-1">
--方向--
</option>
</select>
<span id="d1" style="color: red;"></span>
</body>
</html>
servlet 页面
package web;
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 YY extends HttpServlet {
public void service(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
String uri = request.getRequestURI();
String url = uri.substring(uri.lastIndexOf("/"),uri.lastIndexOf("."));
PrintWriter out = response.getWriter();
if(url.equals("/jjll")){
String kemu=request.getParameter("km");
System.out.println(kemu);
out.print(kemu);
}
}
}
不知道原因是什么
