1 <%--
2 Created by IntelliJ IDEA.
3 User: x1c
4 Date: 2019-12-22
5 Time: 10:04
6 To change this template use File | Settings | File Templates.
7 --%>
8 <%@ page contentType="text/html;charset=UTF-8" language="java" %>
9 <html>
10 <head>
11 <title>$Title$</title>
12 <script>
13 //function里面的参数如果写value 则获取不到
14 function fun1(val){
15 var xhr= new XMLHttpRequest();
16 xhr.open("GET","phoneServlet?val="+val,true)
17 xhr.onreadystatechange=function () {
18 //只有完成后才显示
19 if(xhr.readyState==4&&xhr.status==200){
20 //获取响应的文本内容
21 var phone = xhr.responseText;
22 //包头不包尾
23 var phone3= phone.substring(1,phone.length-1)
24
25 var phone4 =phone3.split(", ");
26
27 var phone2= document.getElementById("p");
28 //清空原有数据
29 phone2.innerHTML="<option >-请选择机型-</option>"
30 for(var i in phone4){
31 phone2.innerHTML+="<option>"+phone4[i]+"</option>"
32 }
33
34 }
35
36
37
38 }
39 xhr.send(null)
40 }
41
42 </script>
43 </head>
44 <body>
45 <select onchange="fun1(this.value)">
46 <option >-请选择手机品牌-</option>
47 <option value="1">华为</option>
48 <option value="2">小米</option>
49 <option value="3">oppo</option>
50 </select>
51 <select id="p">
52 <option >-请选择机型-</option>
53 </select>
54 </body>
55 </html>
package com.bj;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
@WebServlet("/phoneServlet")
public class PhoneServlet extends HttpServlet {
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
String value = req.getParameter("val");
List<String> Phone = new ArrayList<String>();
if(value.equals("1")){
Phone.add("HAWEIMATE9 PRO");
Phone.add("HAWEIMATE10 PRO");
Phone.add("HAWEIMATE20 PRO");
} else if("2".equals(value)){
Phone.add("小米4");
Phone.add("小米8");
Phone.add("小米2s");
} else if("3".equals(value)){
Phone.add("OPPOX");
Phone.add("OPPOXx");
Phone.add("OPPOXxx");
}
resp.setCharacterEncoding("UTF-8");
resp.setContentType("text/html;charset=UTF-8");
//集合的输处格式
resp.getWriter().print(Phone.toString());
}
}
