MVC2 项目实践
组员:黄杰辉 201731062223
谢仁峻 201731062209
一、数据库访问层
创建一个BaseDao,用于继承，方便之后的操作
package Dao.Impl;
import Utils.JdbcUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;
public abstract class BaseDao {
private QueryRunner queryRunner = new QueryRunner();
public int update(String sql, Object... args) {
Connection connection = JdbcUtils.getConnection();
try {
return queryRunner.update(connection, sql, args);
} catch (SQLException e) {
e.printStackTrace();
} finally {
JdbcUtils.close(connection);
}
return -1;
}
public T queryForOne(Class type, String sql, Object... args) {
Connection con = JdbcUtils.getConnection();
try {
return queryRunner.query(con, sql, new BeanHandler(type), args);
} catch (SQLException e) {
e.printStackTrace();
} finally {
JdbcUtils.close(con);
}
return null;
}
public List queryForList(Class type, String sql, Object... args) {
Connection con = JdbcUtils.getConnection();
try {
return queryRunner.query(con, sql, new BeanListHandler(type), args);
} catch (SQLException e) {
e.printStackTrace();
} finally {
JdbcUtils.close(con);
}
return null;
}
public Object queryForSingleValue(String sql, Object... args){
Connection conn = JdbcUtils.getConnection();
try {
return queryRunner.query(conn, sql, new ScalarHandler(), args);
} catch (Exception e) {
e.printStackTrace();
} finally {
JdbcUtils.close(conn);
}
return null;
}
}
创建NewsDao接口，定义增删改查的方法
package Dao;
import Entity.News;
import java.util.List;
public interface NewsDao {
public int addNews(News news);
public int deleteNews( Integer id);
public int updateNews(News news);
public News queryNewsById(Integer id);
public List queryNews();
}
创建NewsDaoImpl实现NewsDao接口，具体实现新闻数据的增删改查
package Dao.Impl;
import Dao.NewsDao;
import Entity.News;
import java.util.List;
public class NewsDaoImpl extends BaseDao implements NewsDao {
@Override
public int addNews(News news) {
String sql = "insert into news(`title`,`content`,`author`,`date`) values(?,?,?,?)";
return update(sql,news.getTitle(),news.getContent(),news.getAuthor(),news.getDate());
}
@Override
public int deleteNews(Integer id) {
String sql = "delete from news where id = ?";
return update(sql,id);
}
@Override
public int updateNews(News news) {
String sql = "update news set `title` = ?, `content`= ?,`author`= ?,`date`= ? where id = ?";
System.out.println(news);
return update(sql,news.getTitle(),news.getContent(),news.getAuthor(),news.getDate(),news.getId());
}
@Override
public News queryNewsById(Integer id) {
String sql = "select * from news where id = ?";
return queryForOne(News.class,sql,id);
}
@Override
public List queryNews() {
String sql = "select * from news";
return queryForList(News.class,sql);
}
}
二、业务逻辑层
创建NewsService
package Service;
import Entity.News;
import java.util.List;
public interface NewsService {
public void addNews(News news);
public void deleteNewsById(Integer id);
public void updateNews(News news);
public News queryNewsById(Integer id);
public List queryNews();
}
创建NewsService的实现类
package Service.Impl;
import Dao.Impl.NewsDaoImpl;
import Dao.NewsDao;
import Entity.News;
import Service.NewsService;
import java.util.List;
public class NewsServiceImpl implements NewsService {
private NewsDao newsDao = new NewsDaoImpl();
@Override
public void addNews(News news) {
newsDao.addNews(news);
}
@Override
public void deleteNewsById(Integer id) {
newsDao.deleteNews(id);
}
@Override
public void updateNews(News news) {
newsDao.updateNews(news);
}
@Override
public News queryNewsById(Integer id) {
return newsDao.queryNewsById(id);
}
@Override
public List queryNews() {
return newsDao.queryNews();
}
}
三、控制层
创建BaseServlet，用于继承
package Controller;
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.lang.reflect.Method;
public abstract class BaseServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doPost(req, resp);
}
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
req.setCharacterEncoding("UTF-8");
String action = req.getParameter("action");
try {
Method method = this.getClass().getDeclaredMethod(action, HttpServletRequest.class, HttpServletResponse.class);
method.invoke(this, req, resp);
} catch (Exception e) {
e.printStackTrace();
}
}
}
创建WebUtil工具类，将参数转化为实体对象
package Utils;
import org.apache.commons.beanutils.BeanUtils;
import java.util.Map;
public class WebUtils {
public static T copyParamToBean( Map value , T bean ){
try {
System.out.println("注入之前：" + bean);
BeanUtils.populate(bean, value);
System.out.println("注入之后：" + bean);
} catch (Exception e) {
e.printStackTrace();
}
return bean;
}
public static int parseInt(String strInt,int defaultValue) {
try {
return Integer.parseInt(strInt);
} catch (Exception e) {
e.printStackTrace();
}
return defaultValue;
}
}
创建NewsServlet类
package Controller;
import Entity.News;
import Service.Impl.NewsServiceImpl;
import Service.NewsService;
import Utils.WebUtils;
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("/Controller.NewsServlet")
public class NewsServlet extends BaseServlet {
private Service.NewsService NewsService = new NewsServiceImpl();
protected void add(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
News News = WebUtils.copyParamToBean(req.getParameterMap(),new News());
NewsService.addNews(News);
resp.sendRedirect(req.getContextPath() + "/Controller.NewsServlet?action=list");
}
protected void delete(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
int id = WebUtils.parseInt(req.getParameter("id"), 0);
NewsService.deleteNewsById(id);
resp.sendRedirect(req.getContextPath() + "/Controller.NewsServlet?action=list");
}
protected void update(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
News News = WebUtils.copyParamToBean(req.getParameterMap(),new News());
NewsService.updateNews(News);
resp.sendRedirect(req.getContextPath() + "/Controller.NewsServlet?action=list");
}
protected void getNews(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
int id = WebUtils.parseInt(req.getParameter("id"), 0);
News News = NewsService.queryNewsById(id);
req.setAttribute("News", News) ;
req.getRequestDispatcher("/pages/manager/news_edit.jsp").forward(req,resp);
}
protected void list(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
List News = NewsService.queryNews();
req.setAttribute("News", News);
req.getRequestDispatcher("/pages/manager/news_manager.jsp").forward(req,resp);
System.out.println(News);
}
}
四、视图层
创建news_manager.jsp,用于显示新闻列表
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
产品管理
新闻管理
创建news_edit,作为添加，修改信息的界面
<%@ page contentType="text/html;charset=UTF-8" language="java" %>编辑图书