给我写一个图书管理系统java和mysql

好的，以下是一个基于Java和MySQL的图书管理系统的示例代码，包括数据库表结构和数据访问层的实现。

Java代码：

import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class BookManagementSystem {
    private static final String DB_URL = "jdbc:mysql://localhost:3306/bookstore?useSSL=false&serverTimezone=UTC";
    private static final String DB_USER = "root";
    private static final String DB_PASSWORD = "password";

    // 查询所有图书
    public static List<Book> getAllBooks() {
        List<Book> books = new ArrayList<>();
        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;
        try {
            conn = DriverManager.getConnection(DB_URL, DB_USER, DB_PASSWORD);
            stmt = conn.createStatement();
            String sql = "SELECT * FROM books";
            rs = stmt.executeQuery(sql);
            while (rs.next()) {
                Book book = new Book();
                book.setId(rs.getInt("id"));
                book.setTitle(rs.getString("title"));
                book.setAuthor(rs.getString("author"));
                book.setGenre(rs.getString("genre"));
                book.setPrice(rs.getDouble("price"));
                books.add(book);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            closeConnection(conn, stmt, rs);
        }
        return books;
    }

    // 根据ID查询图书
    public static Book getBookById(int id) {
        Book book = null;
        Connection conn = null;
        PreparedStatement pstmt = null;
        ResultSet rs = null;
        try {
            conn = DriverManager.getConnection(DB_URL, DB_USER, DB_PASSWORD);
            String sql = "SELECT * FROM books WHERE id = ?";
            pstmt = conn.prepareStatement(sql);
            pstmt.setInt(1, id);
            rs = pstmt.executeQuery();
            if (rs.next()) {
                book = new Book();
                book.setId(rs.getInt("id"));
                book.setTitle(rs.getString("title"));
                book.setAuthor(rs.getString("author"));
                book.setGenre(rs.getString("genre"));
                book.setPrice(rs.getDouble("price"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            closeConnection(conn, pstmt, rs);
        }
        return book;
    }

    // 添加图书
    public static void addBook(Book book) {
        Connection conn = null;
        PreparedStatement pstmt = null;
        try {
            conn = DriverManager.getConnection(DB_URL, DB_USER, DB_PASSWORD);
            String sql = "INSERT INTO books(title, author, genre, price) VALUES (?, ?, ?, ?)";
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, book.getTitle());
            pstmt.setString(2, book.getAuthor());
            pstmt.setString(3, book.getGenre());
            pstmt.setDouble(4, book.getPrice());
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            closeConnection(conn, pstmt, null);
        }
    }

    // 更新图书
    public static void updateBook(Book book) {
        Connection conn = null;
        PreparedStatement pstmt = null;
        try {
            conn = DriverManager.getConnection(DB_URL, DB_USER, DB_PASSWORD);
            String sql = "UPDATE books SET title = ?, author = ?, genre = ?, price = ? WHERE id = ?";
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, book.getTitle());
            pstmt.setString(2, book.getAuthor());
            pstmt.setString(3, book.getGenre());
            pstmt.setDouble(4, book.getPrice());
            pstmt.setInt(5, book.getId());
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            closeConnection(conn, pstmt, null);
        }
    }

    // 删除图书
    public static void deleteBook(int id) {
        Connection conn = null;
        PreparedStatement pstmt = null;
        try {
            conn = DriverManager.getConnection(DB_URL, DB_USER, DB_PASSWORD);
            String sql = "DELETE FROM books WHERE id = ?";
            pstmt = conn.prepareStatement(sql);
            pstmt.setInt(1, id);
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            closeConnection(conn, pstmt, null);
        }
    }

    // 关闭数据库连接
    private static void closeConnection(Connection conn, Statement stmt, ResultSet rs) {
        try {
            if (rs != null) {
                rs.close();
            }
            if (stmt != null) {
                stmt.close();
            }
            if (conn != null) {
                conn.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

Book类：

public class Book {
    private int id;
    private String title;
    private String author;
    private String genre;
    private double price;

    public Book() {
    }

    public Book(int id, String title, String author, String genre, double price) {
        this.id = id;
        this.title = title;
        this.author = author;
        this.genre = genre;
        this.price = price;
    }

    // 省略getter和setter方法
}

MySQL数据库表结构：

CREATE TABLE IF NOT EXISTS books (
    id INT(11) NOT NULL AUTO_INCREMENT,
    title VARCHAR(255) NOT NULL,
    author VARCHAR(255) NOT NULL,
    genre VARCHAR(255) NOT NULL,
    price DOUBLE NOT NULL,
    PRIMARY KEY (id)
);

该系统采用了基于PreparedStatement的数据访问方式，能够有效地防止SQL注入攻击。同时，该系统提供了添加、查询、更新和删除图书的功能，可以根据需要进行扩展。