<%--
Created by IntelliJ IDEA.
User: zongwei
Date: 2020/3/15
Time: 下午10:51
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
<script type="text/javascript" src="js/jquery-3.4.1.min.js"></script>
<script>
$(function(){
var btn = $('#btn');
btn.click(function(){
$.ajax({
url : '/ajaxServlet',
type : 'post',
dataType : 'text',
success : function(data){
var text = $('#id');
text.before(data + '<br/>');
}
})
});
});
</script>
</head>
<body>
<input type="text" name="id" id="id"/>
<input id="btn" type="submit" value="提交" />
</body>
</html><%--
Created by IntelliJ IDEA.
User: zongwei
Date: 2020/3/15
Time: 下午11:25
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
<script type="text/javascript" src="js/jquery-3.4.1.min.js"></script>
<script>
$(function(){
var text = $('#btn');
text.click(function(){
$.ajax({
url : '/ajaxServlet2',
type : 'post',
dataType : 'json',
success : function(data){
$('#id').val(data.id);
$('#name').val(data.name);
$('#age').val(data.age);
}
})
})
})
</script>
</head>
<body>
<input id="id" type="text" /><br/>
<input id="name" type="text" /><br/>
<input id="age" type="text" /><br/>
<input type="button" id="btn" />
</body>
</html>package com.claudxyz.servlet;
import com.claudxyz.entity.User;
import net.sf.json.JSONObject;
import net.sf.json.processors.JsonBeanProcessor;
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;
@WebServlet("/ajaxServlet2")
public class AjaxServlet2 extends HttpServlet {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
User user = new User("1","xxxx",20);
JSONObject jsonObject = JSONObject.fromObject(user);
resp.setCharacterEncoding("UTF-8");
resp.getWriter().write(jsonObject.toString());
}
}package com.claudxyz.servlet;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
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.HashMap;
import java.util.List;
import java.util.Map;
@WebServlet("/changeServlet")
public class ChangeServlet extends HttpServlet {
static private Map<String, List<String>> resultMap = new HashMap<>();
static List<String> list = new ArrayList<>();
static {
list.add("鼓楼区");
list.add("下关区");
list.add("秦淮区");
resultMap.put("南京市",list);
list = new ArrayList<>();
list.add("扬州A区");
list.add("扬州B区");
list.add("扬州C区");
resultMap.put("扬州市",list);
list = new ArrayList<>();
list.add("镇江A区");
list.add("镇江B区");
list.add("镇江C区");
resultMap.put("镇江市",list);
list = new ArrayList<>();
list.add("南京市");
list.add("扬州市");
list.add("镇江市");
resultMap.put("江苏省",list);
list = new ArrayList<>();
list.add("杭州市");
list.add("嘉兴市");
list.add("温州市");
resultMap.put("浙江省",list);
list = new ArrayList<>();
list.add("合肥市");
list.add("滁州市");
list.add("马鞍山市");
resultMap.put("安徽省",list);
list = new ArrayList<>();
list.add("杭州A区");
list.add("杭州B区");
list.add("杭州C区");
resultMap.put("杭州市",list);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
resp.setCharacterEncoding("UTF-8");
String type = req.getParameter("type");
String id = req.getParameter("id");
switch (type){
case "1" :
List<String> cityMap = resultMap.get(id);
String areaValue = cityMap.get(0);
List<String> areaList = resultMap.get(areaValue);
Map<String,Object> reslutMap = new HashMap<>();
reslutMap.put("c",cityMap);
reslutMap.put("a",areaList);
JSONObject jsonObject = JSONObject.fromObject(reslutMap);
resp.getWriter().write(jsonObject.toString());
break;
case "2" :
List<String> areaMap = resultMap.get(id);
JSONArray jsonArray = JSONArray.fromObject(areaMap);
resp.getWriter().write(jsonArray.toString());
break;
}
}
}<%--
Created by IntelliJ IDEA.
User: claudxyz
Date: 2020-3-16
Time: 14:53
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
<script type="text/javascript" src="js/jquery-1.8.0.js"></script>
<script>
$(function(){
var province = $('#province');
province.change(function(){
var privinceValue = $(this).val();
$.ajax({
url : '/J2eeProject/changeServlet',
type : 'POST',
data : 'id=' + privinceValue + '&type=1',
dataType : 'json',
success : function(data){
var cityValue = '';
for(var i = 0;i < data.c.length;i++){
cityValue += '<option value=' + data.c[i] + '>' + data.c[i] +'</option>'
}
$('#city').html(cityValue);
var areaValue = '';
for(var i = 0;i < data.a.length;i++){
areaValue += '<option value=' + data.a[i] + '>' + data.a[i] +'</option>'
}
$('#area').html(areaValue);
}
})
});
var city = $('#city');
city.change(function(){
var cityValue = $(this).val();
$.ajax({
url : '/J2eeProject/changeServlet',
type : 'POST',
data : 'id=' + cityValue + '&type=2',
dataType : 'json',
success: function(data){
var area = '';
for(var i = 0;i < data.length;i++){
area += '<option value=' + data[i] + '>' + data[i] +'</option>'
}
$('#area').html(area);
}
})
});
})
</script>
</head>
<body>
省：<select id="province" name="province">
<option value="江苏省">江苏省</option>
<option value="浙江省">浙江省</option>
<option value="安徽省">安徽省</option>
</select>
市：<select id="city" name="city">
<option value="南京市">南京市</option>
<option value="扬州市">扬州市</option>
<option value="镇江市">镇江市</option>
</select>
区：<select id="area" name="area">
<option value="00_1_1">鼓楼区</option>
<option value="00_1_2">下关区</option>
<option value="00_1_3">江北新区</option>
</select>
</body>
</html>原文：https://www.cnblogs.com/claduxyz/p/12501003.html