Ajax は州と市区町村の 3 レベルのカスケードを実現します

     
    请选择省   请选择市   请选择市   确定 
  

package cn.bestchance.servlet; import java.io.IOException; import java.util.ArrayList; 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 cn.bestchance.dao.AddressDao; import cn.bestchance.dao.impl.AddressDaoImpl; import cn.bestchance.entity.Address; import net.sf.json.JSONArray; import net.sf.json.JSONObject; @WebServlet("/addressSerlvet") public class AddressSerlvet extends HttpServlet { private static final long serialVersionUID = 1L; private AddressDao dao = new AddressDaoImpl(); protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse * response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); String method=request.getParameter("method"); if("provincial".equals(method)){ getProvincial(request, response); } if("city".equals(method)){ getCity(request, response); } if("area".equals(method)){ getArea(request, response); } } /** * 根据市id获取该市下的区的全部信息 * @param request * @param response * @throws ServletException * @throws IOException */ protected void getArea(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String cityId = request.getParameter("cityId"); // 从数据库中查询省的信息 ArrayList
 areaList = dao.getAreaByCityId(Integer.parseInt(cityId)); // 将集合转成json字符串 JSONObject jsonObj = new JSONObject(); JSONArray jsonArray = JSONArray.fromObject(areaList); jsonObj.put("areaList", jsonArray); String jsonDataStr = jsonObj.toString(); response.getWriter().print(jsonDataStr); } /** * 获取省的信息 并相应 * @param request * @param response * @throws ServletException * @throws IOException */ protected void getProvincial(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 从数据库中查询省的信息 ArrayList
 addrList = dao.getProvince(); // 将集合转成json字符串 JSONObject jsonObj = new JSONObject(); JSONArray jsonArray = JSONArray.fromObject(addrList); jsonObj.put("addrList", jsonArray); String jsonDataStr = jsonObj.toString(); response.getWriter().print(jsonDataStr); } /** * 获取市的信息并相应 * @param request * @param response * @throws ServletException * @throws IOException */ protected void getCity(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String provinceId = request.getParameter("provincial"); // 从数据库中查询省的信息 ArrayList
 addrList = dao.getCityByProvinceId(Integer.parseInt(provinceId)); // 将集合转成json字符串 JSONObject jsonObj = new JSONObject(); JSONArray jsonArray = JSONArray.fromObject(addrList); jsonObj.put("cityList", jsonArray); String jsonDataStr = jsonObj.toString(); response.getWriter().print(jsonDataStr); } }

package cn.bestchance.dao; import java.util.ArrayList; import cn.bestchance.entity.Address; public interface AddressDao { /** * 获取省的id和名称 * @return */ ArrayList
 getProvince(); /** * 根据省的id获取市的信息 * @param provinceId * @return */ ArrayList
 getCityByProvinceId(int provinceId); /** * 根据市的id获取区的信息 * @param cityId * @return */ ArrayList
 getAreaByCityId(int cityId); }

package cn.bestchance.dao.impl; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import cn.bestchance.dao.AddressDao; import cn.bestchance.entity.Address; import cn.bestchance.util.DBUtil; public class AddressDaoImpl implements AddressDao { private DBUtil db = new DBUtil(); @Override public ArrayList
 getProvince() { ArrayList
 addrList = new ArrayList
(); db.openConnection(); String sql = "select * from province"; ResultSet rs = db.excuteQuery(sql); try { while(rs.next()){ Address addr = new Address(); addr.setId(rs.getInt(2)); addr.setAddress(rs.getString(3)); addrList.add(addr); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ if(rs != null){ try { rs.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } db.closeResoure(); } return addrList; } @Override public ArrayList
 getCityByProvinceId(int provinceId) { ArrayList
 addrList = new ArrayList
(); db.openConnection(); String sql = "select * from city where fatherID = " + provinceId; //431200 ResultSet rs = db.excuteQuery(sql); try { while(rs.next()){ Address addr = new Address(); addr.setId(rs.getInt(2)); addr.setAddress(rs.getString(3)); addrList.add(addr); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ if(rs != null){ try { rs.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } db.closeResoure(); } return addrList; } @Override public ArrayList
 getAreaByCityId(int cityId) { ArrayList
 addrList = new ArrayList
(); db.openConnection(); String sql = "select * from area where fatherID = " + cityId; //431200 ResultSet rs = db.excuteQuery(sql); try { while(rs.next()){ Address addr = new Address(); addr.setId(rs.getInt(2)); addr.setAddress(rs.getString(3)); addrList.add(addr); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ if(rs != null){ try { rs.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } db.closeResoure(); } return addrList; } }

package cn.bestchance.entity; public class Address { @Override public String toString() { return "Address [id=" + id + ", address=" + address + "]"; } private int id; private String address; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } public Address() { super(); // TODO Auto-generated constructor stub } public Address(int id, String address) { super(); this.id = id; this.address = address; } }