明人不说暗话，直接上代码。
jsp页面代码：
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>注册用户</title> </head> <script src="js/jquery-1.11.3.min.js"></script> <body> <form id="frm"> 住址: <select name="province" class="province"> <option selected="selected" value="0">请选择</option> </select> <select name="city" class="city"> <option selected="selected" value="0">请选择</option> </select> <select name="area" class="area"> <option selected="selected" value="0">请选择</option> </select> </form> </body> <script> //初始化省级 $.ajax({ url:"AddressServlet", type:"post", dataType:"text", data:"", success:function (data) { //将json字符串转化为json对象 var json=JSON.parse(data); //遍历出省 for(var i=0;i<json.length;i++){ $(".province").append("<option value="+json[i].pId+">"+ json[i].pName+ "</option>"); } }, error:function () { alert("服务器内部错误！"); } }); //省改变时触发 $(".province").change(function () { var pId=$(this).val(); $.ajax({ url:"CitiesEchoServlet", type:"post", dataType:"text", data:{pId:pId}, success:function (data) { //将json字符串转化为json对象 var json=JSON.parse(data); //清空市和区 $(".city").html("<option selected='selected' value='0'>请选择</option>"); $(".area").html("<option selected='selected' value='0'>请选择</option>"); //遍历出市 for(var i=0;i<json.length;i++){ $(".city").append("<option value="+json[i].cId+">"+ json[i].cName+ "</option>"); } }, error:function () { alert("服务器内部错误！"); } }); }); //市改变时触发 $(".city").change(function () { var cId=$(this).val(); $.ajax({ url:"AreasEchoServlet", type:"post", dataType:"text", data:{cId:cId}, success:function (data) { var json=JSON.parse(data); $(".area").html("<option selected='selected' value='0'>请选择</option>"); for(var i=0;i<json.length;i++){ $(".area").append("<option value="+json[i].areaId+">"+ json[i].areaName+ "</option>"); } }, error:function () { alert("服务器内部错误！"); } }); }); }) </script> </html>
从后台获取省级数据的servlet
package servlet; import bean.Province; import com.alibaba.fastjson.JSON; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.support.ClassPathXmlApplicationContext; import service.ProvinceService; import javax.servlet.ServletConfig; import javax.servlet.ServletContext; 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.io.PrintWriter; import java.util.List; @WebServlet(value = "/AddressServlet") public class AddressServlet extends HttpServlet { @Autowired private ProvinceService ps; @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); response.setContentType("text/html;charset=UTF-8"); PrintWriter out = response.getWriter(); List<Province> provs=ps.provinceList(); out.write(JSON.toJSONString(provs));//这里是使用了FastJson中的方法将list集合解析成json字符串 } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } //这里是重写httpservlet类中的init方法，从ioc容器中获得ProvinceServiceImpl对象 @Override public void init(ServletConfig config) { ServletContext sc = config.getServletContext(); ps=(ProvinceService) ((ClassPathXmlApplicationContext)sc.getAttribute("context")).getBean("provinceServiceImpl"); } }
获得市级数据的servlet：
package servlet; import bean.City; import com.alibaba.fastjson.JSON; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.support.ClassPathXmlApplicationContext; import service.CityService; import javax.servlet.ServletConfig; import javax.servlet.ServletContext; 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.io.PrintWriter; import java.util.List; @WebServlet(value = "/CitiesEchoServlet") public class CitiesEchoServlet extends HttpServlet { @Autowired private CityService cs; @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); response.setContentType("text/html;charset=UTF-8"); PrintWriter out = response.getWriter(); String pId=request.getParameter("pId"); List<City> citiesById=cs.citiesById(Integer.parseInt(pId)); out.write(JSON.toJSONString(citiesById));//将list集合转化为json字符串并返回 } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } @Override public void init(ServletConfig config) { ServletContext sc = config.getServletContext(); cs=(CityService)((ClassPathXmlApplicationContext)sc.getAttribute("context")).getBean("cityServiceImpl"); } }
获得区级的servlet：
package servlet; import bean.Area; import com.alibaba.fastjson.JSON; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.support.ClassPathXmlApplicationContext; import service.AreaService; import javax.servlet.ServletConfig; import javax.servlet.ServletContext; 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.io.PrintWriter; import java.util.List; @WebServlet(value = "/AreasEchoServlet") public class AreasEchoServlet extends HttpServlet { @Autowired private AreaService as; @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); response.setContentType("text/html;charset=UTF-8"); PrintWriter out = response.getWriter(); String cId=request.getParameter("cId"); List<Area> areasById=as.areasById(Integer.parseInt(cId)); out.write(JSON.toJSONString(areasById));//将list集合转化为json字符串并返回 } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } @Override public void init(ServletConfig config) { ServletContext sc = config.getServletContext(); as=(AreaService)((ClassPathXmlApplicationContext)sc.getAttribute("context")).getBean("areaServiceImpl"); } }