Ajax（下，ajax+js 实现省市区三级联动）-CFANZ编程社区

Ajax实现省市区三级联动

js实现省市区三级联动(一个下拉框实现、页面可以多次引用)
在这里插入图片描述
html+js代码


<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
    <script src="js/jquery-1.8.3.js" type="text/javascript"></script>
</head>
<script type="text/javascript">
    $(function () {
        $.ajax({
            type:"get",
            url:"ProvinceServlet",
            dataType:"json",
            success:function (data) {
                for (var i = 0; i <data.length ; i++) {
                    $("#province").append("  <option value='"+data[i].pid+"'>"+data[i].pname+"</option>")
                }
            }
        });
        $("#province").change(function () {
            $("#city option:gt(0)").remove();
            $("#district option:gt(0)").remove();
            $.ajax({
                type:"get",
                url:"CityServlet?pid="+$("#province").val(),
                dataType:"json",
                success:function (data) {
                    for (var i = 0; i <data.length ; i++) {
                        $("#city").append("  <option value='"+data[i].pid+"'>"+data[i].cname+"</option>")
                    }
                }
            });
        });
        $("#city").change(function () {
            $("#district option:gt(0)").remove();
            $.ajax({
                type:"get",
                url:"DistrictServlet?cid="+$("#city").val(),
                dataType:"json",
                success:function (data) {
                    for (var i = 0; i <data.length ; i++) {
                        $("#district").append("  <option value='"+data[i].cid+"'>"+data[i].dname+"</option>")
                    }
                }
            });
        });
    });
</script>
<body>
        <select id="province">
            <option>请选择</option>
        </select>省
        <select id="city">
            <option>请选择</option>
        </select>市
        <select id="district">
            <option>请选择</option>
        </select>区

</body>
</html>

Java代码

package com.zy.servlet.threelevel;

import com.zy.dao.ThreeLevelDao;
import com.zy.impl.ThreeLevelDaoImpl;
import net.sf.json.JSONArray;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.util.List;

@WebServlet(name = "CityServlet", value = "/CityServlet")
public class CityServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request,response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String pid=request.getParameter("pid");
        System.out.println(" pid "+pid);
        ThreeLevelDao dao = new ThreeLevelDaoImpl();
        List clist= dao.CityLevel(Integer.parseInt(pid));
        JSONArray json = JSONArray.fromObject(clist);
        System.out.println(" json "+json);
        response.getWriter().write(json.toString());

    }
}

package com.zy.servlet.threelevel;

import com.zy.dao.ThreeLevelDao;
import com.zy.impl.ThreeLevelDaoImpl;
import net.sf.json.JSONArray;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.util.List;

@WebServlet(name = "DistrictServlet", value = "/DistrictServlet")
public class DistrictServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request,response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String cid=request.getParameter("cid");
        System.out.println(" cid "+cid);
        ThreeLevelDao dao = new ThreeLevelDaoImpl();
        List dlist= dao.DistrictcLevel(Integer.parseInt(cid));
        JSONArray json = JSONArray.fromObject(dlist);
        System.out.println(" json "+json);
        response.getWriter().write(json.toString());
    }
}

package com.zy.servlet.threelevel;

import com.zy.dao.ThreeLevelDao;
import com.zy.entity.Province;
import com.zy.impl.ThreeLevelDaoImpl;
import net.sf.json.JSONArray;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.util.List;

@WebServlet(name = "ProvinceServlet", value = "/ProvinceServlet")
public class ProvinceServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request,response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        ThreeLevelDao threeLevelDao = new ThreeLevelDaoImpl();
        List<Province> plist= threeLevelDao.ProvinceLevel();
        JSONArray json=JSONArray.fromObject(plist);
        System.out.println(" json "+json);
        response.getWriter().write(json.toString());


    }
}