基于javaweb+mysql的jsp+servlet图书借阅管理系统(java+jsp+bootstrap+jquery+servlet+mysql)

由于提供的系统代码较为复杂且完整，以下是一个简化版本的核心功能代码示例，展示了如何使用JSP、Servlet和JDBC来实现图书借阅管理系统的查询功能。

// BookBorrowingServlet.java
@WebServlet("/book/borrow")
public class BookBorrowingServlet extends HttpServlet {
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String bookId = request.getParameter("bookId");
        Connection conn = null;
        PreparedStatement pstmt = null;
        ResultSet rs = null;
 
        try {
            conn = DatabaseConnection.getConnection();
            String sql = "SELECT * FROM books WHERE id = ?";
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, bookId);
            rs = pstmt.executeQuery();
 
            if (rs.next()) {
                // 设置请求属性，以便在JSP中使用
                request.setAttribute("book", new Book(rs.getInt("id"), rs.getString("title"), rs.getString("author")));
                // 请求转发到显示书籍详情的JSP页面
                request.getRequestDispatcher("/bookDetails.jsp").forward(request, response);
            } else {
                // 书籍未找到，设置错误消息并重定向到错误处理页面
                request.setAttribute("errorMessage", "书籍未找到！");
                request.getRequestDispatcher("/error.jsp").forward(request, response);
            }
        } catch (SQLException | ClassNotFoundException e) {
            e.printStackTrace();
            // 数据库操作失败，设置错误消息并重定向到错误处理页面
            request.setAttribute("errorMessage", "数据库操作失败！");
            request.getRequestDispatcher("/error.jsp").forward(request, response);
        } finally {
            DatabaseConnection.closeResources(conn, pstmt, rs);
        }
    }
}
 
// DatabaseConnection.java
public class DatabaseConnection {
    private static final String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver";
    private static final String DATABASE_URL = "jdbc:mysql://localhost:3306/library_system";
    private static final String DATABASE_USER = "root";
    private static final String DATABASE_PASSWORD = "password";
 
    public static Connection getConnection() throws SQLException, ClassNotFoundException {
        Class.forName(JDBC_DRIVER);
        return DriverManager.getConnection(DATABASE_URL, DATABASE_USER, DATABASE_PASSWORD);
    }
 
    public static void closeResources(Connection conn, PreparedStatement pstmt, ResultSet rs) {
        t