CascadeController.java
package com.huawei.controller;
import java.io.IOException;
import java.util.List;import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.cdsxt.po.Area;
import com.cdsxt.po.City;import com.cdsxt.po.Province;import com.cdsxt.service.CascadeService;import com.google.gson.Gson;/**
* Servlet implementation class CascadeController */public class CascadeController extends HttpServlet { private static final long serialVersionUID = 1L; private CascadeService cascadeService = new CascadeService(); /** * @see HttpServlet#HttpServlet() */ public CascadeController() { super(); // TODO Auto-generated constructor stub }/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub this.doPost(request, response); }/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub request.setCharacterEncoding("UTF-8"); response.setCharacterEncoding("UTF-8"); String _method = request.getParameter("_method"); if("findAllProvince".equals(_method)){ this.findAllProvince(request, response); }else if("findCityByProvinceID".equals(_method)){ this.findCityByProvinceID(request, response); }else if("findAreaByCityID".equals(_method)){ this.findAreaByCityID(request, response); } } protected void findAllProvince(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { List<Province> provinces = this.cascadeService.findAllProvince(); response.getWriter().write(new Gson().toJson(provinces)); } protected void findCityByProvinceID(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String privinceID = request.getParameter("id"); List<City> cities = this.cascadeService.findCityByProvinceID(Integer.parseInt(privinceID)); response.getWriter().write(new Gson().toJson(cities)); } protected void findAreaByCityID(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String cityID = request.getParameter("id"); List<Area> areas = this.cascadeService.findAreaByCityID(Integer.parseInt(cityID)); response.getWriter().write(new Gson().toJson(areas)); }}
CascadeService.java
public class CascadeService {
private CascadeDAO cascadeDAO = new CascadeDAO();
public List<Province> findAllProvince(){ return this.cascadeDAO.findAllProvince(); } public List<City> findCityByProvinceID(Integer provinceID){ return this.cascadeDAO.findCityByProvinceID(provinceID); } public List<Area> findAreaByCityID(Integer cityID){ return this.cascadeDAO.findAreaByCityID(cityID); }}
CascadeDAO.java
package com.cdsxt.dao;
public class CascadeDAO {
public List<Province> findAllProvince(){
List<Province> result = new ArrayList<Province>(); Connection connection = DBUtil.getConnection(); String sql = "SELECT * FROM province"; PreparedStatement ps = null; ResultSet rs = null; try { ps = connection.prepareStatement(sql); rs = ps.executeQuery(); while(rs.next()){ result.add(new Province(rs.getInt("provinceID"), rs.getString("province"))); } } catch (Exception e) { e.printStackTrace(); }finally{ DBUtil.close(rs,ps,connection); } return result; } public List<City> findCityByProvinceID(Integer provinceID){ List<City> result = new ArrayList<City>(); Connection connection = DBUtil.getConnection(); String sql = "SELECT * FROM city WHERE provinceID=?"; PreparedStatement ps = null; ResultSet rs = null; try { ps = connection.prepareStatement(sql); ps.setInt(1, provinceID); rs = ps.executeQuery(); while(rs.next()){ result.add(new City(rs.getInt("cityID"), rs.getString("city"))); } } catch (Exception e) { e.printStackTrace(); }finally{ DBUtil.close(rs,ps,connection); } return result; } public List<Area> findAreaByCityID(Integer cityID){ List<Area> result = new ArrayList<Area>(); Connection connection = DBUtil.getConnection(); String sql = "SELECT * FROM area WHERE cityID=?"; PreparedStatement ps = null; ResultSet rs = null; try { ps = connection.prepareStatement(sql); ps.setInt(1, cityID); rs = ps.executeQuery(); while(rs.next()){ result.add(new Area(rs.getInt("areaID"), rs.getString("area"))); } } catch (Exception e) { e.printStackTrace(); }finally{ DBUtil.close(rs,ps,connection); } return result; }}
DBUtil.java
package com.cdsxt.utils;
/**
* @author Administrator * */public class DBUtil {private static Properties properties = new Properties();
static { InputStream in = DBUtil.class.getClassLoader().getResourceAsStream("META-INF/config/db.properties"); try { properties.load(in); } catch (IOException e) { e.printStackTrace(); }finally{ try { in.close(); } catch (IOException e) { e.printStackTrace(); } } } /** * 得到数据库连接 * @return */ public static Connection getConnection(){ //显示加载驱动 try { Class.forName(properties.getProperty("db.driver")); Connection connection = DriverManager.getConnection(properties.getProperty("db.host")+"/"+properties.getProperty("db.name"), properties.getProperty("db.username"), properties.getProperty("db.password")); return connection; } catch (ClassNotFoundException e) { e.printStackTrace(); }catch (SQLException e) { e.printStackTrace(); } return null; } /** * * 释放资源 * @param objects */ public static void close(Object ...objects){ if(objects!=null && objects.length>0){ try { for(Object o:objects){ if(o instanceof ResultSet){ ((ResultSet)o).close(); }else if(o instanceof Statement){ ((Statement)o).close(); }else if(o instanceof Connection){ ((Connection)o).close(); } } } catch (SQLException e) { e.printStackTrace(); } } } public static void main(String[] args) { System.out.println(DBUtil.getConnection()); }}
# MYSQL config
db.driver=com.mysql.jdbc.Driverdb.username=rootdb.password=123456db.name=testdb.host=jdbc:mysql://localhost:3306 # Oracle config