jsp+servlet图书管理

要开发一个基于JSP和Servlet的图书管理系统，需要以下步骤：

1. 设计数据库：需要设计一个数据库来存储图书信息、用户信息、借阅信息等。可以使用MySQL等关系型数据库。

2. 编写DAO层：DAO层是数据访问层，负责与数据库进行交互。可以使用JDBC或者MyBatis等框架来实现。

3. 编写业务逻辑层：业务逻辑层负责处理业务逻辑，例如图书的借阅和归还等。可以使用Java类来实现。

4. 编写控制器层：控制器层负责接收用户请求，并将请求转发到对应的业务逻辑层处理。可以使用Servlet来实现。

5. 编写视图层：视图层负责展现数据，例如展示图书列表、用户信息等。可以使用JSP来实现。

6. 部署应用程序：将应用程序打包成WAR文件，部署到Tomcat等Web服务器上。

以下是一个简单的示例：

1. 设计数据库：

CREATE TABLE book (
  id INT PRIMARY KEY AUTO_INCREMENT,
  title VARCHAR(100) NOT NULL,
  author VARCHAR(50) NOT NULL,
  price DECIMAL(10, 2) NOT NULL,
  stock INT NOT NULL
);

CREATE TABLE user (
  id INT PRIMARY KEY AUTO_INCREMENT,
  username VARCHAR(50) NOT NULL,
  password VARCHAR(50) NOT NULL,
  name VARCHAR(50) NOT NULL,
  role ENUM('admin', 'user') NOT NULL
);

CREATE TABLE borrow (
  id INT PRIMARY KEY AUTO_INCREMENT,
  user_id INT NOT NULL,
  book_id INT NOT NULL,
  borrow_date DATE NOT NULL,
  return_date DATE,
  FOREIGN KEY (user_id) REFERENCES user(id),
  FOREIGN KEY (book_id) REFERENCES book(id)
);

2. 编写DAO层：

BookDao.java

public interface BookDao {
    List<Book> findAll();
    Book findById(int id);
    void save(Book book);
    void update(Book book);
    void delete(int id);
}

BookDaoImpl.java

public class BookDaoImpl implements BookDao {
    private Connection conn;

    public BookDaoImpl(Connection conn) {
        this.conn = conn;
    }

    public List<Book> findAll() {
        List<Book> books = new ArrayList<Book>();
        try {
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery("SELECT * FROM book");
            while (rs.next()) {
                Book book = new Book();
                book.setId(rs.getInt("id"));
                book.setTitle(rs.getString("title"));
                book.setAuthor(rs.getString("author"));
                book.setPrice(rs.getDouble("price"));
                book.setStock(rs.getInt("stock"));
                books.add(book);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return books;
    }

    public Book findById(int id) {
        Book book = null;
        try {
            PreparedStatement stmt = conn.prepareStatement("SELECT * FROM book WHERE id=?");
            stmt.setInt(1, id);
            ResultSet rs = stmt.executeQuery();
            if (rs.next()) {
                book = new Book();
                book.setId(rs.getInt("id"));
                book.setTitle(rs.getString("title"));
                book.setAuthor(rs.getString("author"));
                book.setPrice(rs.getDouble("price"));
                book.setStock(rs.getInt("stock"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return book;
    }

    public void save(Book book) {
        try {
            PreparedStatement stmt = conn.prepareStatement("INSERT INTO book (title, author, price, stock) VALUES (?, ?, ?, ?)");
            stmt.setString(1, book.getTitle());
            stmt.setString(2, book.getAuthor());
            stmt.setDouble(3, book.getPrice());
            stmt.setInt(4, book.getStock());
            stmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public void update(Book book) {
        try {
            PreparedStatement stmt = conn.prepareStatement("UPDATE book SET title=?, author=?, price=?, stock=? WHERE id=?");
            stmt.setString(1, book.getTitle());
            stmt.setString(2, book.getAuthor());
            stmt.setDouble(3, book.getPrice());
            stmt.setInt(4, book.getStock());
            stmt.setInt(5, book.getId());
            stmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public void delete(int id) {
        try {
            PreparedStatement stmt = conn.prepareStatement("DELETE FROM book WHERE id=?");
            stmt.setInt(1, id);
            stmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

UserDao.java

public interface UserDao {
    User findByUsername(String username);
    void save(User user);
}

UserDaoImpl.java

public class UserDaoImpl implements UserDao {
    private Connection conn;

    public UserDaoImpl(Connection conn) {
        this.conn = conn;
    }

    public User findByUsername(String username) {
        User user = null;
        try {
            PreparedStatement stmt = conn.prepareStatement("SELECT * FROM user WHERE username=?");
            stmt.setString(1, username);
            ResultSet rs = stmt.executeQuery();
            if (rs.next()) {
                user = new User();
                user.setId(rs.getInt("id"));
                user.setUsername(rs.getString("username"));
                user.setPassword(rs.getString("password"));
                user.setName(rs.getString("name"));
                user.setRole(rs.getString("role"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return user;
    }

    public void save(User user) {
        try {
            PreparedStatement stmt = conn.prepareStatement("INSERT INTO user (username, password, name, role) VALUES (?, ?, ?, ?)");
            stmt.setString(1, user.getUsername());
            stmt.setString(2, user.getPassword());
            stmt.setString(3, user.getName());
            stmt.setString(4, user.getRole());
            stmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

BorrowDao.java

public interface BorrowDao {
    List<Borrow> findByUserId(int userId);
    List<Borrow> findByBookId(int bookId);
    List<Borrow> findAll();
    void save(Borrow borrow);
    void update(Borrow borrow);
    void delete(int id);
}

BorrowDaoImpl.java

public class BorrowDaoImpl implements BorrowDao {
    private Connection conn;

    public BorrowDaoImpl(Connection conn) {
        this.conn = conn;
    }

    public List<Borrow> findByUserId(int userId) {
        List<Borrow> borrows = new ArrayList<Borrow>();
        try {
            PreparedStatement stmt = conn.prepareStatement("SELECT * FROM borrow WHERE user_id=?");
            stmt.setInt(1, userId);
            ResultSet rs = stmt.executeQuery();
            while (rs.next()) {
                Borrow borrow = new Borrow();
                borrow.setId(rs.getInt("id"));
                borrow.setUserId(rs.getInt("user_id"));
                borrow.setBookId(rs.getInt("book_id"));
                borrow.setBorrowDate(rs.getDate("borrow_date"));
                borrow.setReturnDate(rs.getDate("return_date"));
                borrows.add(borrow);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return borrows;
    }

    public List<Borrow> findByBookId(int bookId) {
        List<Borrow> borrows = new ArrayList<Borrow>();
        try {
            PreparedStatement stmt = conn.prepareStatement("SELECT * FROM borrow WHERE book_id=?");
            stmt.setInt(1, bookId);
            ResultSet rs = stmt.executeQuery();
            while (rs.next()) {
                Borrow borrow = new Borrow();
                borrow.setId(rs.getInt("id"));
                borrow.setUserId(rs.getInt("user_id"));
                borrow.setBookId(rs.getInt("book_id"));
                borrow.setBorrowDate(rs.getDate("borrow_date"));
                borrow.setReturnDate(rs.getDate("return_date"));
                borrows.add(borrow);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return borrows;
    }

    public List<Borrow> findAll() {
        List<Borrow> borrows = new ArrayList<Borrow>();
        try {
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery("SELECT * FROM borrow");
            while (rs.next()) {
                Borrow borrow = new Borrow();
                borrow.setId(rs.getInt("id"));
                borrow.setUserId(rs.getInt("user_id"));
                borrow.setBookId(rs.getInt("book_id"));
                borrow.setBorrowDate(rs.getDate("borrow_date"));
                borrow.setReturnDate(rs.getDate("return_date"));
                borrows.add(borrow);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return borrows;
    }

    public void save(Borrow borrow) {
        try {
            PreparedStatement stmt = conn.prepareStatement("INSERT INTO borrow (user_id, book_id, borrow_date) VALUES (?, ?, ?)");
            stmt.setInt(1, borrow.getUserId());
            stmt.setInt(2, borrow.getBookId());
            stmt.setDate(3, borrow.getBorrowDate());
            stmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public void update(Borrow borrow) {
        try {
            PreparedStatement stmt = conn.prepareStatement("UPDATE borrow SET user_id=?, book_id=?, borrow_date=?, return_date=? WHERE id=?");
            stmt.setInt(1, borrow.getUserId());
            stmt.setInt(2, borrow.getBookId());
            stmt.setDate(3, borrow.getBorrowDate());
            stmt.setDate(4, borrow.getReturnDate());
            stmt.setInt(5, borrow.getId());
            stmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public void delete(int id) {
        try {
            PreparedStatement stmt = conn.prepareStatement("DELETE FROM borrow WHERE id=?");
            stmt.setInt(1, id);
            stmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

3. 编写业务逻辑层：

BookService.java

public interface BookService {
    List<Book> findAll();
    Book findById(int id);
    void save(Book book);
    void update(Book book);
    void delete(int id);
}

BookServiceImpl.java

public class BookServiceImpl implements BookService {
    private BookDao bookDao;

    public BookServiceImpl(BookDao bookDao) {
        this.bookDao = bookDao;
    }

    public List<Book> findAll() {
        return bookDao.findAll();
    }

    public Book findById(int id) {
        return bookDao.findById(id);
    }

    public void save(Book book) {
        bookDao.save(book);
    }

    public void update(Book book) {
        bookDao.update(book);
    }

    public void delete(int id) {
        bookDao.delete(id);
    }
}

UserService.java

public interface UserService {
    User login(String username, String password);
    void register(User user);
}

UserServiceImpl.java

public class UserServiceImpl implements UserService {
    private UserDao userDao;

    public UserServiceImpl(UserDao userDao) {
        this.userDao = userDao;
    }

    public User login(String username, String password) {
        User user = userDao.findByUsername(username);
        if (user != null && user.getPassword().equals(password)) {
            return user;
        }
        return null;
    }

    public void register(User user) {
        userDao.save(user);
    }
}

BorrowService.java

public interface BorrowService {
    List<Borrow> findByUserId(int userId);
    List<Borrow> findByBookId(int bookId);
    List<Borrow> findAll();
    void borrow(int userId, int bookId);
    void returnBook(int borrowId);
}

BorrowServiceImpl.java

public class BorrowServiceImpl implements BorrowService {
    private BorrowDao borrowDao;

    public BorrowServiceImpl(BorrowDao borrowDao) {
        this.borrowDao = borrowDao;
    }

    public List<Borrow> findByUserId(int userId) {
        return borrowDao.findByUserId(userId);
    }

    public List<Borrow> findByBookId(int bookId) {
        return borrowDao.findByBookId(bookId);
    }

    public List<Borrow> findAll() {
        return borrowDao.findAll();
    }

    public void borrow(int userId, int bookId) {
        Borrow borrow = new Borrow();
        borrow.setUserId(userId);
        borrow.setBookId(bookId);
        borrow.setBorrowDate(new java.sql.Date(System.currentTimeMillis()));
        borrowDao.save(borrow);
    }

    public void returnBook(int borrowId) {
        Borrow borrow = borrowDao.findById(borrowId);
        borrow.setReturnDate(new java.sql.Date(System.currentTimeMillis()));
        borrowDao.update(borrow);
    }
}

4. 编写控制器层：

BookServlet.java

public class BookServlet extends HttpServlet {
    private BookService bookService;

    public void init() {
        bookService = new BookServiceImpl(new BookDaoImpl(DbUtil.getConnection()));
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String action = request.getParameter("action");
        if ("list".equals(action)) {
            List<Book> books = bookService.findAll();
            request.setAttribute("books", books);
            request.getRequestDispatcher("/bookList.jsp").forward(request, response);
        } else if ("add".equals(action)) {
            request.getRequestDispatcher("/bookForm.jsp").forward(request, response);
        } else if ("edit".equals(action)) {
            int id = Integer.parseInt(request.getParameter("id"));
            Book book = bookService.findById(id);
            request.setAttribute("book", book);
            request.getRequestDispatcher("/bookForm.jsp").forward(request, response);
        } else if ("delete".equals(action)) {
            int id = Integer.parseInt(request.getParameter("id"));
            bookService.delete(id);
            response.sendRedirect(request.getContextPath() + "/book?action=list");
        }
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String action = request.getParameter("action");
        if ("save".equals(action)) {
            int id = Integer.parseInt(request.getParameter("id"));
            String title = request.getParameter("title");
            String author = request.getParameter("author");
            double price = Double.parseDouble(request.getParameter("price"));
            int stock = Integer.parseInt(request.getParameter("stock"));
            Book book = new Book();
            book.setId(id);
            book.setTitle(title);
            book.setAuthor(author);
            book.setPrice(price);
            book.setStock(stock);
            if (id == 0) {
                bookService.save(book);
            } else {
                bookService.update(book);
            }
            response.sendRedirect(request.getContextPath() + "/book?action=list");
        }
    }
}

UserServlet.java

public class UserServlet extends HttpServlet {
    private UserService userService;

    public void init() {
        userService = new UserServiceImpl(new UserDaoImpl(DbUtil.getConnection()));
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String action = request.getParameter("action");
        if ("login".equals(action)) {
            request.getRequestDispatcher("/login.jsp").forward(request, response);
        } else if ("logout".equals(action)) {
            request.getSession().invalidate();
            response.sendRedirect(request.getContextPath() + "/book?action=list");
        } else if ("register".equals(action)) {
            request.getRequestDispatcher("/register.jsp").forward(request, response);
        }
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String action = request.getParameter("action");
        if ("login".equals(action)) {
            String username = request.getParameter("username");
            String password = request.getParameter("password");
            User user = userService.login(username, password);
            if (user != null) {
                request.getSession().setAttribute("user", user);
                response.sendRedirect(request.getContextPath() + "/book?action=list");
            } else {
                request.setAttribute("error", "用户名或密码错误");
                request.getRequestDispatcher("/login.jsp").forward(request, response);
            }
        } else if ("register".equals(action)) {
            String username = request.getParameter("username");
            String password = request.getParameter("password");
            String name = request.getParameter("name");
            User user = new User();
            user.setUsername(username);
            user.setPassword(password);
            user.setName(name);
            user.setRole("user");
            userService.register(user);
            response.sendRedirect(request.getContextPath() + "/user?action=login");
        }
    }
}

BorrowServlet.java

public class BorrowServlet extends HttpServlet {
    private BorrowService borrowService;

    public void init() {
        borrowService = new BorrowServiceImpl(new BorrowDaoImpl(DbUtil.getConnection()));
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String action = request.getParameter("action");
        if ("list".equals(action)) {
            List<Borrow> borrows = borrowService.findAll();
            request.setAttribute("borrows", borrows);
            request.getRequestDispatcher("/borrowList.jsp").forward(request, response);
        } else if ("borrow".equals(action)) {
            int bookId = Integer.parseInt(request.getParameter("bookId"));
            User user = (User) request.getSession().getAttribute("user");
            borrowService.borrow(user.getId(), bookId);
            response.sendRedirect(request.getContextPath() + "/borrow?action=list");
        } else if ("return".equals(action)) {
            int borrowId = Integer.parseInt(request.getParameter("borrowId"));
            borrowService.returnBook(borrowId);
            response.sendRedirect(request.getContextPath() + "/borrow?action=list");
        }
    }
}

5. 编写视图层：

bookList.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>图书列表</title>
</head>
<body>
    <h1>图书列表</h1>
    <a href="<%=request.getContextPath()%>/book?action=add">添加图书</a>
    <table border="1">
        <thead>
            <tr>
                <th>ID</th>
                <th>书名</th>
                <th>作者</th>
                <th>价格</th>
                <th>库存</th>
                <th>操作</th>
            </tr>
        </thead>
        <tbody>
            <c:forEach items="${books}" var="book">
                <tr>
                    <td>${book.id}</td>
                    <td>${book.title}</td>
                    <td>${book.author}</td>
                    <td>${book.price}</td>
                    <td>${book.stock}</td>
                    <td>
                        <a href="<%=request.getContextPath()%>/book?action=edit&id=${book.id}">编辑</a>
                        <