javaweb实验：Java Web综合应用开发__基于MVC模式

目录

• 前言
• 实验目的
• 实验原理
• 实验内容
• 实验过程
• • 项目结构
  • 代码实现
  • Java代码
  • • controller层
    • • AddNewsServlet类
      • DeletrNewsServlet类
      • LoginServlet类
      • LogoutServlet类
      • QueryAllNewsServlet类
      • QueryNewsServlet类
      • RegisterServlet类
      • UpdateNewsServlet类
    • dao层
    • • NewsDao类
      • UserDao类
    • daoimpl层
    • • NewsDaoImpl类
      • UserDaoImpl类
    • entity层
    • • News类
      • PageBean类
      • User类
    • service层
    • • NewsService类
      • UserService类
    • serviceimpl层
    • • NewsServiceImpl类
      • UserServiceImpl类
    • util层
  • jsp代码
  • • • addNews
      • displayNews
      • login
      • login_failure
      • queryAllNews
      • reg_failure
      • reg_success
      • register
      • updateNews
    • 配置web.xml
    • 成果
  • 分页查询
• 总结

前言

本实验的目的是让学生掌握Java Web开发的基本原理和方法，以及MVC设计模式的应用。MVC是一种将程序分为三个部分的设计模式，即模型（Model）、视图（View）和控制器（Controller）。模型负责封装数据和业务逻辑，视图负责展示用户界面，控制器负责接收用户请求并调用模型和视图进行处理。MVC模式可以提高程序的可维护性、可扩展性和可重用性，是一种常用的Web开发模式。

本实验要求学生使用JSP、Servlet和JavaBean技术，实现一个简单的在线图书管理系统。该系统可以实现用户注册、登录、浏览图书、借阅图书、归还图书等功能。学生需要按照MVC模式，将程序分为三个层次，即数据访问层、业务逻辑层和表现层。数据访问层使用Druid连接池和JDBC技术，对MySQL数据库进行操作。业务逻辑层使用JavaBean封装数据和业务方法。表现层使用JSP和HTML构建用户界面，并使用Servlet作为控制器，接收用户请求并调用业务逻辑层进行处理。

本实验报告将详细介绍本实验的设计思路、实现步骤、运行结果和遇到的问题。希望通过本实验，学生能够深入理解Java Web开发的原理和方法，以及MVC设计模式的优势和应用。

实验目的

理解MVC模式，并能够熟练使用MVC模式，综合运用JSP、JavaBean（DAO模式）和Servlet等相关技术，进行Web应用程序的开发。

实验原理

关于MVC模式
MVC是一个设计模式，它强制性的使应用程序的输入、处理和输出分开。使用MVC设计模式被分成三个核心层：模型层、视图层、控制层。它们各自处理自己的任务。各层的任务如下：
模型层（Model）：完成一个个独立的业务操作组件，一般都是以JavaBean的形式进行定义的。
控制层（Controller）：此层由Servlet实现，负责所有的用户请求参数，判断请求参数是否合法，根据请求的类型调用JavaBean执行操作并将最终的处理结果交由显示层进行显示。
显示层（View）：此层主要是负责接收Servlet传递的内容，并且调用JavaBean，将内容显示给用户。
如图1所示。使用MVC模式进行Web程序开发，是以Servlet为主体展开的，由Servlet接收所有的客户端请求，根据请求调用相应的JavaBean，并将所有的显示结果交给JSP完成。

实验内容

[贯穿项目] 使用MVC模式，综合运用JSP、JavaBean（DAO模式）和Servlet等相关技术，实现新闻管理系统。要求提供如下功能：用户登录，用户注册，新闻的增、查、改、删。
关于创建项目创建数据库等内容在此就不多赘述

实验过程

项目结构

代码实现

Java代码

controller层

AddNewsServlet类

import java.io.IOException;import java.text.DateFormat;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Date;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 nuc.ss.entity.News;import nuc.ss.service.NewsService;import nuc.ss.serviceimpl.NewsServiceImpl;@WebServlet("/addNews")public class AddNewsServlet extends HttpServlet {protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {// 1、解决编码问题req.setCharacterEncoding("utf-8");resp.setCharacterEncoding("utf-8");resp.setContentType("text/html;charset=utf-8");//2、接受前台数据，并将前台数据封装成一个News对象String title = req.getParameter("title");String author = req.getParameter("author");String content = req.getParameter("content");String date_str = req.getParameter("enterdate");String hot_str = req.getParameter("hot");// String-->Util.DateDateFormat df = new SimpleDateFormat("yyyy-MM-dd");Date date;int hot;News news = null;try {date = df.parse(date_str);hot = Integer.parseInt(hot_str);news = new News(0, title, author, content, date, hot);} catch (ParseException e) {e.printStackTrace();}// 3、调用service层，然后传入newsNewsService ns = new NewsServiceImpl();int n = ns.addNews(news);// 4、处理结果if(n >0) {//插入成功resp.sendRedirect("queryAllNews"); }else {// 插入失败req.getRequestDispatcher("addNews.jsp").forward(req, resp);}}protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {// TODO Auto-generated method stubdoGet(req, resp);}}

DeletrNewsServlet类

import java.io.IOException;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 nuc.ss.service.NewsService;import nuc.ss.serviceimpl.NewsServiceImpl;@WebServlet("/deleteNews")public class DeleteNewsServlet extends HttpServlet {protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {// 1、解决编码问题req.setCharacterEncoding("utf-8");//resp.setCharacterEncoding("utf-8");resp.setContentType("text/html;charset=utf-8");// 2、获取前台传过来的idint id = Integer.parseInt(req.getParameter("id"));// 3、调用Service层NewsService ns = new NewsServiceImpl();int n = ns.removeNews(id);// 4、处理结果if(n>0) {//删除成功，则直接刷新页面resp.sendRedirect("queryAllNews");}else {resp.getWriter().println("删除失败！");}}protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {// TODO Auto-generated method stubdoGet(req, resp);}}

LoginServlet类

import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.Cookie;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import nuc.ss.entity.User;import nuc.ss.service.UserService;import nuc.ss.serviceimpl.UserServiceImpl;@WebServlet("/login")public class LoginServlet extends HttpServlet {protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//获取前台数据 request.setCharacterEncoding("UTF-8"); String id = request.getParameter("id"); String password = request.getParameter("password"); String remenber = request.getParameter("remenber"); String name; if((!(name=check(id,password)).equals(""))){//登录成功，跳转到成功页Cookie cookie;System.out.println("remenber=" + remenber);// on, null if(remenber != null) {cookie = new Cookie("Cookie2020", id+"#"+password+"#"+remenber);cookie.setMaxAge(45);response.addCookie(cookie);} else {cookie = new Cookie("Cookie2020", id+"#"+password+"#"+remenber);cookie.setMaxAge(0);response.addCookie(cookie); }request.getSession().setAttribute("username", name); request.getSession().setMaxInactiveInterval(30);// 30秒response.sendRedirect("queryAllNews"); }else{//登录失败，跳转到失败页 response.sendRedirect("login_failure.jsp"); }}protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doGet(request, response);}private String check(String userid, String userpwd){String uname = "";UserService us = new UserServiceImpl();User user = us.login(userid, userpwd);if(user != null){//登录成功uname = user.getUname();}return uname; }}

LogoutServlet类

import java.io.IOException;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 javax.servlet.http.HttpSession;@WebServlet("/logout")public class LogoutServlet extends HttpServlet {protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {HttpSession session = request.getSession();session.removeAttribute("username");//跳转到login.jsp response.sendRedirect("login.jsp");}protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {doGet(request, response);}}

QueryAllNewsServlet类

import nuc.ss.entity.News;import nuc.ss.entity.PageBean;import nuc.ss.service.NewsService;import nuc.ss.serviceimpl.NewsServiceImpl;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;@WebServlet("/queryAllNews")public class QueryAllNewsServlet extends HttpServlet {protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {// 1、调用service层，查询新闻NewsService ns = new NewsServiceImpl();List<News> list = ns.queryAllNews();// 2、处理结果req.setAttribute("list", list);req.getRequestDispatcher("queryAllNews.jsp").forward(req, resp);}protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {doGet(req, resp);}}

QueryNewsServlet类

import java.io.IOException;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 nuc.ss.entity.News;import nuc.ss.service.NewsService;import nuc.ss.serviceimpl.NewsServiceImpl;@WebServlet("/queryNews")public class QueryNewsServlet extends HttpServlet {protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {// 1、解决编码问题req.setCharacterEncoding("utf-8");//resp.setCharacterEncoding("utf-8");resp.setContentType("text/html;charset=utf-8");//2、接受前台数据int id = Integer.parseInt(req.getParameter("id"));int flag = Integer.parseInt(req.getParameter("flag"));// 3、调用service层，查询指定id的新闻信息NewsService ns = new NewsServiceImpl();News news = ns.queryOneNews(id);// 4、处理结果if(news != null) {req.setAttribute("news", news);if(flag == 1) {req.getRequestDispatcher("updateNews.jsp").forward(req, resp);}else {req.getRequestDispatcher("displayNews.jsp").forward(req, resp);}}}protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {// TODO Auto-generated method stubdoGet(req, resp);}}

RegisterServlet类

import java.io.IOException;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 nuc.ss.entity.User;import nuc.ss.service.UserService;import nuc.ss.serviceimpl.UserServiceImpl;@WebServlet("/register")public class RegisterServlet extends HttpServlet {protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//设置编码格式req.setCharacterEncoding("UTF-8");//resp.setCharacterEncoding("utf-8");resp.setContentType("text/html;charset=utf-8");//获取前台数据String id = req.getParameter("uid");String name = req.getParameter("uname");String password = req.getParameter("upassword");String password2 = req.getParameter("upassword2");String sex = req.getParameter("usex");String email = req.getParameter("uemail");java.util.Date regdate = new java.util.Date();String uname = check(id,name,password,password2,sex,email,regdate);if(!( "".equals(uname) || "######".equals(uname)|| "******".equals(uname)|| "$$$$$$".equals(uname))){//注册成功，跳转到成功页req.getSession().setAttribute("info", uname);resp.sendRedirect("reg_success.jsp");}else{//注册失败，跳转到失败页String info = "";if("######".equals(uname)){info = "错误：登录ID已经存在！";}if("******".equals(uname)){info = "错误：两次输入密码不一致！";}if("$$$$$$".equals(uname)){info = "错误：所有信息都必须填写！";}req.getSession().setAttribute("info", info);resp.sendRedirect("reg_failure.jsp");}}protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {// TODO Auto-generated method stubdoGet(req, resp);}private String check(String userid, String username, String userpwd, String userpwd2,String usersex, String useremail, java.util.Date userregdate){if("".equals(userid) || "".equals(username) || "".equals(userpwd) || "".equals(userpwd2)){return "$$$$$$";}if(!(userpwd.equals(userpwd2))){return "******";}User user = new User(userid,username,userpwd,usersex,useremail,userregdate);UserService us = new UserServiceImpl();int n = us.register(user);if (n == -1) {return "######";}return username;} }

UpdateNewsServlet类

import java.io.IOException;import java.text.DateFormat;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Date;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 nuc.ss.entity.News;import nuc.ss.service.NewsService;import nuc.ss.serviceimpl.NewsServiceImpl;@WebServlet("/updateNews")public class UpdateNewsServlet extends HttpServlet {protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {// 1、解决编码问题req.setCharacterEncoding("utf-8");resp.setCharacterEncoding("utf-8");resp.setContentType("text/html;charset=utf-8");//2、接受前台数据，并将前台数据封装成一个News对象int id = Integer.parseInt(req.getParameter("id"));String title = req.getParameter("title");String author = req.getParameter("author");String content = req.getParameter("content");String date_str = req.getParameter("enterdate");String hot_str = req.getParameter("hot");// String-->Util.DateDateFormat df = new SimpleDateFormat("yyyy-MM-dd");Date date;int hot;News news = null;try {date = df.parse(date_str);hot = Integer.parseInt(hot_str);news = new News(id, title, author, content, date, hot);} catch (ParseException e) {e.printStackTrace();}// 3、调用service层，然后传入newsNewsService ns = new NewsServiceImpl();int n = ns.updateNews(news);// 4、处理结果if(n >0) {//修改成功resp.sendRedirect("queryAllNews"); }else {// 修改失败resp.sendRedirect("queryAllNews");}}protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {// TODO Auto-generated method stubdoGet(req, resp);}}

dao层

这里是dao的接口

NewsDao类

import nuc.ss.entity.News;import java.util.List;public interface NewsDao {static int getTotalSize() {return 0;}static List<News> queryNewsByPage(int startIndex, int pageSize) {return null;}int insertOne(News news);List<News> selectAll();int deleteOne(int id);News selectOne(int id);int updateOne(News news);}

UserDao类

import nuc.ss.entity.User;public interface UserDao {int insertOne(User user);User findOne(String uid, String pwd);boolean findOne(String uid);}

daoimpl层

NewsDaoImpl类

import nuc.ss.dao.NewsDao;import nuc.ss.entity.News;import nuc.ss.entity.PageBean;import nuc.ss.util.DBUtil;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 NewsDaoImpl implements NewsDao {@Overridepublic int insertOne(News news) {String sql = "insert into t_news values(default," />;Object[] objs = {news.getTitle(), news.getAuthor(), news.getContent(), news.getEnterdate(), news.getHot()};int n = DBUtil.excuteDML(sql, objs);return n;}@Overridepublic List<News> selectAll() {Connection conn = DBUtil.getConnection();String sql = "select * from t_news";PreparedStatement ps = DBUtil.getPreparedStatement(conn, sql);ResultSet rs = null;List<News> list = new ArrayList<News>();try {rs = ps.executeQuery();while(rs.next()) {News news = new News(rs.getInt("id"), rs.getString("title"),rs.getString("author"), rs.getString("content"),rs.getDate("enterdate"), rs.getInt("hot"));list.add(news);}} catch (SQLException e) {e.printStackTrace();} finally {DBUtil.closeAll(rs, ps, conn);}return list;}@Overridepublic int deleteOne(int id) {String sql = "delete from t_news where id=?";Object[] objs = {id};int n = DBUtil.excuteDML(sql, objs);return n;}@Overridepublic News selectOne(int id) {Connection conn = DBUtil.getConnection();String sql = "select * from t_news where id=?";PreparedStatement ps = DBUtil.getPreparedStatement(conn, sql);try {ps.setInt(1, id);} catch (SQLException e1) {e1.printStackTrace();}ResultSet rs = null;News news = null;try {rs = ps.executeQuery();if(rs.next()) {news = new News(rs.getInt("id"), rs.getString("title"),rs.getString("author"), rs.getString("content"),rs.getDate("enterdate"), rs.getInt("hot"));}} catch (SQLException e) {e.printStackTrace();} finally {DBUtil.closeAll(rs, ps, conn);}return news;}@Overridepublic int updateOne(News news) {String sql = "update t_news set title=?,author=?,content=?,enterdate=?,hot=? where id=?";Object[] objs = {news.getTitle(), news.getAuthor(), news.getContent(), news.getEnterdate(), news.getHot(), news.getId()};int n = DBUtil.excuteDML(sql, objs);return n;}public PageBean<News> queryNewsByPage(int currentPage, int pageSize) {// 创建一个PageBean对象PageBean<News> pageBean = new PageBean<News>();// 设置当前页数和每页记录数pageBean.setCurrentPage(currentPage);pageBean.setPageSize(pageSize);// 调用dao层的方法获取总记录数int totalSize = NewsDao.getTotalSize();// 设置总记录数pageBean.setTotalSize(totalSize);// 计算总页数int totalPage = (totalSize % pageSize == 0) ? (totalSize / pageSize) : (totalSize / pageSize + 1);// 设置总页数pageBean.setTotalPage(totalPage);// 计算开始索引int startIndex = (currentPage - 1) * pageSize;// 调用dao层的方法获取当前页数据List<News> list = NewsDao.queryNewsByPage(startIndex, pageSize);// 设置当前页数据pageBean.setList(list);// 返回PageBean对象return pageBean;}}

UserDaoImpl类

import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import nuc.ss.dao.UserDao;import nuc.ss.entity.User;import nuc.ss.util.DBUtil;public class UserDaoImpl implements UserDao{@Overridepublic int insertOne(User user) {String sql = "insert into t_user values (?,?,?,?,?,?)";Object[] objs = {user.getUid(), user.getUname(), user.getUpassword(), user.getUsex(), user.getUemail(), user.getUregdate()};int n = DBUtil.excuteDML(sql, objs);return n;}@Overridepublic User findOne(String uid, String pwd) {Connection conn = DBUtil.getConnection();String sql = "select * from t_user where uid=? and upassword=?";PreparedStatement ps = DBUtil.getPreparedStatement(conn, sql);ResultSet rs = null;User user = null;try {ps.setString(1, uid);ps.setString(2, pwd);rs = ps.executeQuery();if(rs.next()) {user = new User(rs.getString("uid"), rs.getString("uname"), rs.getString("upassword"), rs.getString("usex"), rs.getString("uemail"), rs.getDate("uregdate"));}} catch (SQLException e) {e.printStackTrace();} finally{DBUtil.closeAll(rs, ps, conn);}return user;}@Overridepublic boolean findOne(String uid) {Connection conn = DBUtil.getConnection();String sql = "select * from t_user where uid=?";PreparedStatement ps = DBUtil.getPreparedStatement(conn, sql);ResultSet rs = null;try {ps.setString(1, uid);rs = ps.executeQuery();if(rs.next()) {return true;}} catch (SQLException e) {e.printStackTrace();} finally{DBUtil.closeAll(rs, ps, conn);}return false;}}

entity层

News类

import java.util.Date;public class News {private static int id;private String title;private String author;private String content;private Date enterdate;private int hot;public News(int id, String title, String author, String content, Date enterdate, int hot) {super();this.id = id;this.title = title;this.author = author;this.content = content;this.enterdate = enterdate;this.hot = hot;}public static int getId() {return id;}public void setId(int id) {this.id = id;}public String getTitle() {return title;}public void setTitle(String title) {this.title = title;}public String getAuthor() {return author;}public void setAuthor(String author) {this.author = author;}public String getContent() {return content;}public void setContent(String content) {this.content = content;}public Date getEnterdate() {return enterdate;}public void setEnterdate(Date enterdate) {this.enterdate = enterdate;}public int getHot() {return hot;}public void setHot(int hot) {this.hot = hot;}@Overridepublic String toString() {return "News [id=" + id + ", title=" + title + ", author=" + author + ", content=" + content + ", enterdate="+ enterdate + ", hot=" + hot + "]";}}

PageBean类

import java.util.List;public class PageBean<T> {private Integer currentPage; // 当前页数private Integer totalPage; // 总页数private Integer totalSize; // 总记录数private Integer pageSize; // 每页记录数private List<T> list; // 当前页数据// 构造方法，根据总记录数、当前页数和每页记录数计算总页数public PageBean() {this.totalSize = totalSize;this.currentPage = currentPage;this.pageSize = pageSize;this.totalPage = (totalSize % pageSize == 0) ? (totalSize / pageSize) : (totalSize / pageSize + 1);}// getter和setter方法public Integer getCurrentPage() {return currentPage;}public void setCurrentPage(Integer currentPage) {this.currentPage = currentPage;}public Integer getTotalPage() {return totalPage;}public void setTotalPage(Integer totalPage) {this.totalPage = totalPage;}public Integer getTotalSize() {return totalSize;}public void setTotalSize(Integer totalSize) {this.totalSize = totalSize;}public Integer getPageSize() {return pageSize;}public void setPageSize(Integer pageSize) {this.pageSize = pageSize;}public List<T> getList() {return list;}public void setList(List<T> list) {this.list = list;}}

User类

import java.util.Date;public class User {private String uid;private String uname;private String upassword;private String usex;private String uemail;private Date uregdate;public User(String uid, String uname, String upassword, String usex, String uemail, Date uregdate) {super();this.uid = uid;this.uname = uname;this.upassword = upassword;this.usex = usex;this.uemail = uemail;this.uregdate = uregdate;}public String getUid() {return uid;}public void setUid(String uid) {this.uid = uid;}public String getUname() {return uname;}public void setUname(String uname) {this.uname = uname;}public String getUpassword() {return upassword;}public void setUpassword(String upassword) {this.upassword = upassword;}public String getUsex() {return usex;}public void setUsex(String usex) {this.usex = usex;}public String getUemail() {return uemail;}public void setUemail(String uemail) {this.uemail = uemail;}public Date getUregdate() {return uregdate;}public void setUregdate(Date uregdate) {this.uregdate = uregdate;}@Overridepublic String toString() {return "User [uid=" + uid + ", uname=" + uname + ", upassword=" + upassword + ", usex=" + usex + ", uemail="+ uemail + ", uregdate=" + uregdate + "]";}}

service层

NewsService类

import nuc.ss.entity.News;import nuc.ss.entity.PageBean;import java.util.List;public interface NewsService {int addNews(News news);List<News> queryAllNews();int removeNews(int id);News queryOneNews(int id);int updateNews(News news);int getTotalCount();// 声明一个分页查询的方法PageBean<News> queryNewsByPage(int currentPage, int pageSize);}

UserService类

import nuc.ss.entity.User;public interface UserService {int register(User user);User login(String uid, String pwd);}

serviceimpl层

NewsServiceImpl类

import nuc.ss.dao.NewsDao;import nuc.ss.daoimpl.NewsDaoImpl;import nuc.ss.entity.News;import nuc.ss.entity.PageBean;import nuc.ss.service.NewsService;import java.util.List;public class NewsServiceImpl implements NewsService {private NewsDao nd = new NewsDaoImpl();private NewsServiceImpl newsDao;@Overridepublic int addNews(News news) {return nd.insertOne(news);}@Overridepublic List<News> queryAllNews() {return nd.selectAll();}@Overridepublic int removeNews(int id) {return nd.deleteOne(id);}@Overridepublic News queryOneNews(int id) {return nd.selectOne(id);}@Overridepublic int updateNews(News news) {return nd.updateOne(news);}@Overridepublic int getTotalCount() {return 0;}@Overridepublic PageBean<News> queryNewsByPage(int currentPage, int pageSize) {return null;}public void setNewsDao(NewsDao newsDao) {this.newsDao = (NewsServiceImpl) newsDao;}}

UserServiceImpl类

import nuc.ss.dao.UserDao;import nuc.ss.daoimpl.UserDaoImpl;import nuc.ss.entity.User;import nuc.ss.service.UserService;public class UserServiceImpl implements UserService{private UserDao ud = new UserDaoImpl();@Overridepublic int register(User user) {if(ud.findOne(user.getUid())){return -1;}return ud.insertOne(user);}/*public int register(User user) {return ud.insertOne(user);}*/@Overridepublic User login(String uid, String pwd) {return ud.findOne(uid, pwd);}}

util层

public class DBUtil {public static Connection getConnection() {Connection connection = null;try {Class.forName("com.mysql.jdbc.Driver");System.out.println("加载成功！");String url = "jdbc:mysql://localhost:3306/db_news2019?useUnicode=true&characterEncoding=utf-8";String username = "root";String password = "12345678";connection = DriverManager.getConnection(url, username, password);} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();System.out.println("加载失败！驱动类没有找到！");} catch (SQLException e) {e.printStackTrace();System.out.println("数据库连接失败！请检查数据库名以及用户帐号！");}return connection;}// 关闭资源连接connection,statement,resultsetpublic static void closeAll(ResultSet resultSet, Statement statement, Connection connection) {if(resultSet != null) {try {resultSet.close();} catch (SQLException e) {e.printStackTrace();}}if(statement != null) {try {statement.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}if(connection != null) {try {connection.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}// 创建数据库操作对象preparedStatementpublic static PreparedStatement getPreparedStatement(Connection connection, String sql) {PreparedStatement preparedStatement = null;try {preparedStatement = connection.prepareStatement(sql);} catch (SQLException e) {e.printStackTrace();}return preparedStatement;}// 创建数据库操作对象statementpublic static Statement getStatement(Connection connection) {Statement statement = null;try {statement = connection.createStatement();} catch (SQLException e) {e.printStackTrace();}return statement;}// 封装DML语句（更新操作）public static int excuteDML(String sql, Object...objs) {int n = 0;Connection connection = null;PreparedStatement preparedStatement = null;try {connection = getConnection();preparedStatement = getPreparedStatement(connection, sql);for (int i = 0; i < objs.length; i++) {preparedStatement.setObject(i+1, objs[i]);}n = preparedStatement.executeUpdate();} catch (SQLException e) {e.printStackTrace();}finally {closeAll(null, preparedStatement, connection);}return n;}}

jsp代码

addNews

<%@ page language="java" contentType="text/html; charset=utf-8"pageEncoding="utf-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>增加新闻</title></head><body><form action="addNews" method="post"><table align="center"><tr><td>新闻题目</td><td><input type="text" name="title"></td></tr><tr><td>新闻作者</td><td><input type="text" name="author"></td></tr><tr><td>新闻内容</td><td><textarea rows="5" cols="70" name="content"></textarea> </td></tr><tr><td>新闻日期</td><td><input type="date" name="enterdate"></td></tr><tr><td>新闻热度</td><td><input type="number" name="hot"></td></tr><tr><td colspan="2"><input type="submit" value="添加"></td></tr></table></form></body></html>

displayNews

<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%><%@page import="java.sql.*"%><%@page import="nuc.ss.entity.News"%><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>查询新闻详情</title></head><body><% News news = (News)request.getAttribute("news");if(news != null){%><table align="center"><tr><td>新闻题目</td><td><input type="text" readonly="readonly"value=""></td></tr><tr><td>新闻作者</td><td><input type="text" readonly="readonly"value=""></td></tr><tr><td>新闻内容</td><td><textarea rows="5" cols="70" readonly="readonly"><%=news.getContent() %></textarea> </td></tr><tr><td>新闻日期</td><td><input type="date" readonly="readonly"value=""></td></tr><tr><td>新闻热度</td><td><input type="number" readonly="readonly" value=""></td></tr></table><%}%><br><center><a href="queryAllNews">返回</a></center></body></html>

login

<%@ page contentType="text/html;charset=utf-8" pageEncoding="utf-8"%><html><head><meta http-equiv="Content-Type" content="text/html;charset=utf-8"><title>登录程序之表单页面</title></head><body><%String id = "";String password = "";String remenber = null;Cookie[] cookies = request.getCookies();if(cookies != null){for(int i=0; i<cookies.length; i++){if (cookies[i].getName().equals("Cookie2020")) { //如果cookie对象的名称为Cookie2019id = cookies[i].getValue().split("#")[0];//获取用户名password = cookies[i].getValue().split("#")[1];//获取密码remenber = cookies[i].getValue().split("#")[2];//获取remenber}}}%><center><h1>登录操作</h1><hr><form action="login" method="post"><table border="1"><tr><td colspan="2">用户登录</td> </tr><tr><td>登录ID：</td><td><input type="text" name="id" value=""></td></tr><tr><td>登录密码：</td><td><input type="password" name="password" value=""></td></tr><tr><td colspan="2">&nbsp;&nbsp;<input type="submit" value="登录">&nbsp;&nbsp;<input type="reset" value="重置">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<input type="checkbox" name="remenber"<%if(remenber!=null){%> checked <%}%>>记住我 </td> </tr></table></form><h5>如果您尚未注册，请先进行<a href="register.jsp">&nbsp;注册&nbsp;</a></h5></center></body>

login_failure

<%@ page contentType="text/html;charset=utf-8" pageEncoding="utf-8"%><html><head><meta http-equiv="Content-Type" content="text/html;charset=utf-8"><title>登录程序之登录成功页面</title></head><body><center><h1>登录操作</h1><hr><h2>用户ID或密码错误！请重新<a href="login.jsp">登录</a></h2></center></body>

queryAllNews

<%@ page language="java" contentType="text/html; charset=utf-8"pageEncoding="utf-8"%><%@page import="java.util.*" %><%@page import="nuc.ss.service.NewsService"%><%@page import="nuc.ss.serviceimpl.NewsServiceImpl"%><%@page import="nuc.ss.entity.News"%><%@page import="nuc.ss.entity.User"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>显示所有新闻</title><script type="text/javascript">function del(id){var flag = window.confirm("是否真的要删除？");if(flag){window.location.href = "deleteNews?id=" + id;}}function update(id){window.location.href = "queryNews?id=" + id + "&flag=1";}function query(id){window.location.href = "queryNews?id=" + id + "&flag=0";}</script></head><body><%if(session.getAttribute("username") == null){response.sendRedirect("login.jsp"); }%><table align="center" border="0" width="750px" cellspacing="0"><tr><td align="center" style="font-family:'黑体'; font-size:28px;">登录成功！欢迎[<%=session.getAttribute("username")%>]访问新闻管理系统！</td></tr><tr><td><hr></td></tr><tr style="font-family:'宋体'; font-size:24px;"><td align="right"><a href="addNews.jsp"><b>增加新闻</b></a>&nbsp;&nbsp;<a href="logout">安全退出</a></td></tr></table><tablealign="center" border="1" width="750px" cellspacing="0"><tr><th width="320px">标题</th><th width="120px">作者</th><!-- <th width="600px">内容</th> --><th width="110px">日期</th><th width="50px">热度</th><th width="150px">操作</th></tr><%List<News> list = (List)request.getAttribute("list");for(News news: list){%><tr><td><%=news.getTitle() %></td><td><%=news.getAuthor() %></td><td><%=news.getEnterdate() %></td><td><%=news.getHot() %></td><td><a href="javascript:query()">查询详情</a><a href="javascript:update()">修改</a><a href="javascript:del()">删除</a></td></tr><%}%></table></body></html>

reg_failure

<%@ page contentType="text/html;charset=utf-8" pageEncoding="utf-8"%><html><head><meta http-equiv="Content-Type" content="text/html;charset=utf-8"><title>登录程序之登录成功页面</title></head><body><center><h1>注册操作</h1><hr><h2><%=session.getAttribute("info")%>请重新<a href="register.jsp">注册</a></h2></center></body>

reg_success

<%@ page contentType="text/html;charset=utf-8" pageEncoding="utf-8"%><html><head><meta http-equiv="Content-Type" content="text/html;charset=utf-8"><title>登录程序之登注册成功页面</title></head><body><h2>[<%=session.getAttribute("info")%>]恭喜您--注册成功！</h2><h4>5秒后自动跳转到登录页面</h4><%response.setHeader("refresh", "5;login.jsp");%></body></html>

register

<%@ page contentType="text/html;charset=utf-8" pageEncoding="utf-8"%><html><head><meta http-equiv="Content-Type" content="text/html;charset=utf-8"><title>新闻管理系统之用户注册页面</title></head><body><center><h1>注册操作</h1><hr><form action="register" method="post"><table border="1"><tr><td colspan="2" align="center">用户注册</td> </tr><tr><td align="right">登录ID：</td><td><input type="text" name="uid"></td></tr><tr><td align="right">真实姓名：</td><td><input type="text" name="uname"></td></tr><tr><td align="right">性&nbsp;&nbsp;&nbsp;别：</td><td><input type="radio" name="usex" value="男">男<input type="radio" name="usex" value="女">女</td></tr><tr><td align="right">E-Mail：</td><td><input type="text" name="uemail"></td></tr><tr><td align="right">登录密码：</td><td><input type="password" name="upassword"></td></tr><tr><td align="right">确认密码：</td><td><input type="password" name="upassword2"></td></tr><tr><td colspan="2">&nbsp;&nbsp;<input type="submit" value="注册">&nbsp;&nbsp;<input type="reset" value="重置"> </td> </tr></table></form><h5><a href="login.jsp">&nbsp;返回登录页面&nbsp;</a></h5></center></body>

updateNews

<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%><%@page import="java.sql.*"%><%@page import="nuc.ss.entity.News"%><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>修改新闻</title></head><body><%News news = (News)request.getAttribute("news");%><form action="updateNews" method="post"><input type="hidden" name="id" value=""><table align="center"><tr><td>新闻题目</td><td><input type="text" name="title" value=""></td></tr><tr><td>新闻作者</td><td><input type="text" name="author" value=""></td></tr><tr><td>新闻内容</td><td><textarea rows="5" cols="70" name="content"><%=news.getContent() %></textarea> </td></tr><tr><td>新闻日期</td><td><input type="date" name="enterdate" value=""></td></tr><tr><td>新闻热度</td><td><input type="number" name="hot" value=""></td></tr><tr><td colspan="2"><input type="submit" value="保存修改"></td></tr></table></form><br><center><a href="queryAllNews">返回</a></center></body></html>

配置web.xml

参考配置

ProjforNewsV1_0index.htmlindex.htmindex.jspdefault.htmldefault.htmlogin.jspLoginServletnuc.ss.controller.LoginServletLoginServlet/loginLogoutServletnuc.ss.controller.LogoutServletLogoutServlet/logoutRegisterServletnuc.ss.controller.RegisterServletRegisterServlet/registerQueryAllNewsServletnuc.ss.controller.QueryAllNewsServletQueryAllNewsServlet/queryAllNewsAddNewsServletnuc.ss.controller.AddNewsServletAddNewsServlet/addNewsDeleteNewsServletnuc.ss.controller.DeleteNewsServletDeleteNewsServlet/deleteNewsQueryNewsServletnuc.ss.controller.QueryNewsServletQueryNewsServlet/queryNewsUpdateNewsServletnuc.ss.controller.UpdateNewsServletUpdateNewsServlet/updateNews

成果

登陆界面

注册界面


新闻展示页面

增加新闻

新闻详情

修改页面
删除新闻

分页查询

增加一个分页查询的功能
servlet代码

@WebServlet("/queryAllNews")public class QueryAllNewsServlet extends HttpServlet {protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {// 1、调用service层，查询新闻NewsService ns = new NewsServiceImpl();int currentPage = 1; // 默认为第一页int pageSize = 10; // 默认每页显示10条String currentPageStr = req.getParameter("currentPage"); // 获取请求参数中的当前页数if (currentPageStr != null && !"".equals(currentPageStr)) { // 如果不为空，则转换为整数currentPage = Integer.parseInt(currentPageStr);}String pageSizeStr = req.getParameter("pageSize"); // 获取请求参数中的每页记录数if (pageSizeStr != null && !"".equals(pageSizeStr)) { // 如果不为空，则转换为整数pageSize = Integer.parseInt(pageSizeStr);}PageBean<News> pageBean = ns.queryNewsByPage(currentPage, pageSize); // 调用service层的方法获取PageBean对象// 2、处理结果req.setAttribute("pageBean", pageBean); // 将PageBean对象存入request域中req.getRequestDispatcher("queryAllNews.jsp").forward(req, resp); // 转发到JSP页面显示数据}protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {doGet(req, resp);}}

jsp代码

<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><%@page import="java.util.*" %><%@page import="nuc.ss.service.NewsService"%><%@page import="nuc.ss.serviceimpl.NewsServiceImpl"%><%@page import="nuc.ss.entity.News"%><%@page import="nuc.ss.entity.User"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>显示所有新闻</title><script type="text/javascript">function del(id) {var flag = window.confirm("是否真的要删除？");if (flag) {window.location.href = "deleteNews" /> + id;}}function update(id) {window.location.href = "queryNews?id=" + id + "&flag=1";}function query(id) {window.location.href = "queryNews?id=" + id + "&flag=0";}</script></head><body><% if (session.getAttribute("username") == null) {response.sendRedirect("login.jsp");}%><table align="center" border="0" width="750px" cellspacing="0"><tr><td align="center" style="font-family:'黑体'; font-size:28px;">登录成功！欢迎[<%=session.getAttribute("username")%>]访问新闻管理系统！</td></tr><tr><td><hr></td></tr><tr style="font-family:'宋体'; font-size:24px;"><td align="right"><a href="addNews.jsp"><b>增加新闻</b></a><a href="logout">安全退出</a></td></tr></table><table align="center" border="1" width="750px" cellspacing="0"><tr><th width="320px">标题</th><th width="120px">作者</th><!-- <th width="600px">内容</th> --><th width="110px">日期</th><th width="50px">热度</th><th width="150px">操作</th></tr><c:forEach items="${pageBean.list}" var="news"> <!-- 遍历当前页数据 --><tr><td>${news.title}</td><td>${news.author}</td><td>${news.enterdate}</td><td>${news.hot}</td><td><a href="javascript:query(${news.id})">查询详情</a><a href="javascript:update(${news.id})">修改</a><a href="javascript:del(${news.id})">删除</a></td></tr></c:forEach><tr><td colspan="5" align="center"><span>第${pageBean.currentPage}/${pageBean.totalPage}页 总记录数：${pageBean.totalSize}条 每页${pageBean.pageSize}条</span><c:if test="${pageBean.currentPage > 1}"> <!-- 如果不是第一页，则可以跳转到首页和上一页 --><a href="/queryAllNews?currentPage=1&pageSize=${pageBean.pageSize}">首页</a><a href="/queryAllNews?currentPage=${pageBean.currentPage - 1}&pageSize=${pageBean.pageSize}">上一页</a></c:if><c:if test="${pageBean.currentPage < pageBean.totalPage}"> <!-- 如果不是最后一页，则可以跳转到下一页和末页 --><a href="/queryAllNews?currentPage=${pageBean.currentPage + 1}&pageSize=${pageBean.pageSize}">下一页</a><a href="/queryAllNews?currentPage=${pageBean.totalPage}&pageSize=${pageBean.pageSize}">末页</a></c:if><form action="/queryAllNews" method="get"> <!-- 添加一个表单来实现跳转到指定页 --><input type="text" name="currentPage" size="2"/> <!-- 输入要跳转的页数 --><input type="hidden" name="pageSize" value="${pageBean.pageSize}"/> <!-- 隐藏域保存每页记录数 --><input type="submit" value="跳转"/> <!-- 提交表单 --></form><form action="/queryAllNews" method="get"> <!-- 添加一个表单来实现跳转到指定页 --><input type="text" name="currentPage" size="2"/> <!-- 输入要跳转的页数 --><input type="hidden" name="pageSize" value="${pageBean.pageSize}"/> <!-- 隐藏域保存每页记录数 --><input type="submit" value="跳转"/> <!-- 提交表单 --></form></td> <!-- 结束单元格 --></tr> <!-- 结束表格行 --></table> <!-- 结束表格 -->

在entity层中添加一个pagebean类

public class PageBean<T> {private Integer currentPage; // 当前页数private Integer totalPage; // 总页数private Integer totalSize; // 总记录数private Integer pageSize; // 每页记录数private List<T> list; // 当前页数据// 构造方法，根据总记录数、当前页数和每页记录数计算总页数public PageBean() {this.totalSize = totalSize;this.currentPage = currentPage;this.pageSize = pageSize;this.totalPage = (totalSize % pageSize == 0) ? (totalSize / pageSize) : (totalSize / pageSize + 1);}// getter和setter方法public Integer getCurrentPage() {return currentPage;}public void setCurrentPage(Integer currentPage) {this.currentPage = currentPage;}public Integer getTotalPage() {return totalPage;}public void setTotalPage(Integer totalPage) {this.totalPage = totalPage;}public Integer getTotalSize() {return totalSize;}public void setTotalSize(Integer totalSize) {this.totalSize = totalSize;}public Integer getPageSize() {return pageSize;}public void setPageSize(Integer pageSize) {this.pageSize = pageSize;}public List<T> getList() {return list;}public void setList(List<T> list) {this.list = list;}}

在dao层增加一个方法

public PageBean<News> queryNewsByPage(int currentPage, int pageSize) {// 创建一个PageBean对象PageBean<News> pageBean = new PageBean<News>();// 设置当前页数和每页记录数pageBean.setCurrentPage(currentPage);pageBean.setPageSize(pageSize);// 调用dao层的方法获取总记录数int totalSize = NewsDao.getTotalSize();// 设置总记录数pageBean.setTotalSize(totalSize);// 计算总页数int totalPage = (totalSize % pageSize == 0) ? (totalSize / pageSize) : (totalSize / pageSize + 1);// 设置总页数pageBean.setTotalPage(totalPage);// 计算开始索引int startIndex = (currentPage - 1) * pageSize;// 调用dao层的方法获取当前页数据List<News> list = NewsDao.queryNewsByPage(startIndex, pageSize);// 设置当前页数据pageBean.setList(list);// 返回PageBean对象return pageBean;}

展示一下成果吧

以上就是这次实验的全部内容啦

总结

本文是对javaweb实验的总结，主要介绍了基于MVC模式的web应用开发的过程和心得。MVC模式是一种设计模式，将web应用分为三个层次：模型（Model）、视图（View）和控制器（Controller）。模型负责封装业务逻辑和数据，视图负责展示用户界面，控制器负责处理用户请求和调用模型和视图。MVC模式的优点是可以实现高内聚低耦合，提高代码的可维护性和可重用性。

在本实验中，我使用了idea作为开发工具，Tomcat作为web服务器，MySQL作为数据库，JSP和Servlet作为视图和控制器，JavaBean作为模型。我实现了一个简单的登录系统和新闻管理系统，包括登录、注册、查询、修改、删除等功能。在开发过程中，我遵循了MVC模式的原则，将不同的功能分配到不同的层次，使得代码结构清晰，易于修改和扩展。我也遇到了一些困难和问题，例如如何保持用户的登录状态，如何防止SQL注入攻击，如何处理中文乱码等。通过查阅资料和调试代码，我逐一解决了这些问题，并从中学习到了很多知识和技巧。

总之，通过本实验，我深刻理解了MVC模式的原理和优势，掌握了基于MVC模式的web应用开发的方法和步骤，提高了我的编程能力和解决问题的能力。我认为这是一次非常有意义和有价值的实验，对于我的未来学习和工作都有很大的帮助。