Ajax实现省市县三级联动_AJAX相关_

 import java.util.List; public interface ProvinceDao { List findAll(); }

 import java.util.List; public interface CityDao { List findCityByPid(int pid); }

 import java.util.List; public interface AreaDao { List findAreaByCid(int cid); }

 import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; public class ProvinceDaoImpl implements ProvinceDao{ public List findAll(){ Connection conn = DBHelper.getConn(); ArrayList provinces = new ArrayList(); String sql = "select * from aprovince"; try { PreparedStatement ps = conn.prepareStatement(sql); ResultSet rs = ps.executeQuery(); while (rs.next()){ Province p = new Province(); p.setPid(rs.getInt(1)); p.setPname(rs.getString(2)); provinces.add(p); } } catch (SQLException e) { e.printStackTrace(); } return provinces; } }

 import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; public class CityDaoImpl implements CityDao { @Override public List findCityByPid(int pid) { Connection conn = DBHelper.getConn(); ArrayList cities = new ArrayList<>(); String sql = "select * from acity where pid=?"; try { PreparedStatement ps = conn.prepareStatement(sql); ps.setInt(1,pid); ResultSet rs = ps.executeQuery(); while (rs.next()){ City city = new City(); city.setPid(rs.getInt(3)); city.setCid(rs.getInt(1)); city.setCname(rs.getString(2)); cities.add(city); } } catch (SQLException e) { e.printStackTrace(); } return cities; } }

 import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; public class AreaDaoImpl implements AreaDao { @Override public List findAreaByCid(int cid) { Connection conn = DBHelper.getConn(); ArrayList areas = new ArrayList<>(); String sql = "select * from aarea where cid=?"; try { PreparedStatement ps = conn.prepareStatement(sql); ps.setInt(1,cid); ResultSet rs = ps.executeQuery(); while (rs.next()){ Area area = new Area(); area.setCid(rs.getInt(3)); area.setAid(rs.getInt(1)); area.setAname(rs.getString(2)); areas.add(area); } } catch (SQLException e) { e.printStackTrace(); } return areas; } }

 package cn.zhc.servlet; import cn.zhc.dao.Impl.ProvinceDaoImpl; import cn.zhc.dao.ProvinceDao; import cn.zhc.domin.Province; import com.alibaba.fastjson.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.List; @WebServlet("/findAll") public class FindAll extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); ProvinceDao provinceDao = new ProvinceDaoImpl(); List lists=provinceDao.findAll(); response.getWriter().write(JSONObject.toJSONString(lists)); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } }

 package cn.zhc.servlet; import cn.zhc.dao.CityDao; import cn.zhc.dao.Impl.CityDaoImpl; import cn.zhc.domin.City; import com.alibaba.fastjson.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.List; @WebServlet("/findCityByPid") public class FindCityByPid extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); String pid = request.getParameter("pid"); CityDao cityDao = new CityDaoImpl(); List cityList = cityDao.findCityByPid(Integer.parseInt(pid)); response.getWriter().write(JSONObject.toJSONString(cityList)); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } }

 package cn.zhc.servlet; import cn.zhc.dao.AreaDao; import cn.zhc.dao.Impl.AreaDaoImpl; import cn.zhc.domin.Area; import com.alibaba.fastjson.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.List; @WebServlet("/findAreaByCid") public class FindAreaByCid extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); String cid = request.getParameter("cid"); AreaDao areaDao = new AreaDaoImpl(); List areas = areaDao.findAreaByCid(Integer.parseInt(cid)); response.getWriter().write(JSONObject.toJSONString(areas)); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doPost(request, response); } }

<%@ page contentType="text/html;charset=UTF-8" language="java" %>请选择省 请选择市 请选择县