Deleting Error

 <form th:action="@{/admin/deletestudentbook}" method="post" style="display:inline;">
                    <input type="hidden" name="roll_no" th:value="${studentAllBooks.roll_no}" />
                    <input type="hidden" name="book_id" th:value="${book.bookId}" />
                    <button type="submit" class="absolute top-2 right-2 text-gray-500 hover:text-red-500">
                        <i class="fas fa-trash-alt"></i>   <!-- Dustbin Icon -->
                    </button>
                </form>

 <form th:action="@{/admin/deletestudentbook}" method="post" style="display:inline;">
                    <input type="hidden" name="roll_no" th:value="${studentAllBooks.roll_no}" />
                    <input type="hidden" name="book_id" th:value="${book.bookId}" />
                    <button type="submit" class="absolute top-2 right-2 text-gray-500 hover:text-red-500">
                        <i class="fas fa-trash-alt"></i>   <!-- Dustbin Icon -->
                    </button>
                </form>

@PostMapping("/deletestudentbook")
    public String deleteStudentBook(@RequestParam Long roll_no, Long book_id, Model model) {
        log.debug("Received request to delete student book. roll_no: {}, book_id: {}", roll_no, book_id);

        StudentDetailsDto studentDetails = studentDetailsService.getStudentById(roll_no)
                .orElseThrow(() -> {
                    log.error("Student not found for roll_no: {}", roll_no);
                    return new StudentNotFound("No Student Found");
                });

        model.addAttribute("studentAllBooks", studentDetails);

        if (studentDetails.getBooksDetails().size() == 1) {
            log.debug("Deleting student books and details. roll_no: {}", roll_no);
            studentDetailsService.deleteStudentBooks(roll_no, book_id);
            studentDetailsService.deleteStudentDetails(roll_no);
            return "redirect:/";
        } else {
            log.debug("Deleting student books. roll_no: {}", roll_no);
            studentDetailsService.deleteStudentBooks(roll_no, book_id);
            return "allbooks";
        }

    }
}

@PostMapping("/deletestudentbook")
    public String deleteStudentBook(@RequestParam Long roll_no, Long book_id, Model model) {
        log.debug("Received request to delete student book. roll_no: {}, book_id: {}", roll_no, book_id);

        StudentDetailsDto studentDetails = studentDetailsService.getStudentById(roll_no)
                .orElseThrow(() -> {
                    log.error("Student not found for roll_no: {}", roll_no);
                    return new StudentNotFound("No Student Found");
                });

        model.addAttribute("studentAllBooks", studentDetails);

        if (studentDetails.getBooksDetails().size() == 1) {
            log.debug("Deleting student books and details. roll_no: {}", roll_no);
            studentDetailsService.deleteStudentBooks(roll_no, book_id);
            studentDetailsService.deleteStudentDetails(roll_no);
            return "redirect:/";
        } else {
            log.debug("Deleting student books. roll_no: {}", roll_no);
            studentDetailsService.deleteStudentBooks(roll_no, book_id);
            return "allbooks";
        }

    }
}

llers.AdminController#studentAllBooks(Long, Model)
2024-09-28T20:27:57.996+05:30 DEBUG 6724 --- [nio-8080-exec-1] org.hibernate.SQL                        : select sd1_0.roll_no,sd1_0.email,sd1_0.name,sd1_0.phone_number from student_details sd1_0 where sd1_0.roll_no=?
Hibernate: select sd1_0.roll_no,sd1_0.email,sd1_0.name,sd1_0.phone_number from student_details sd1_0 where sd1_0.roll_no=?
2024-09-28T20:27:58.002+05:30 DEBUG 6724 --- [nio-8080-exec-1] org.hibernate.SQL                        : select bd1_0.user_roll_no,bd1_0.book_id,bd1_0.authors,bd1_0.book_name,bd1_0.book_pdf,bd1_0.currency_code,bd1_0.description,bd1_0.image,bd1_0.issue_date,bd1_0.price,bd1_0.publish_date,bd1_0.return_date,bd1_0.subtitle,bd1_0.synposis from book_details bd1_0 where bd1_0.user_roll_no=?
Hibernate: select bd1_0.user_roll_no,bd1_0.book_id,bd1_0.authors,bd1_0.book_name,bd1_0.book_pdf,bd1_0.currency_code,bd1_0.description,bd1_0.image,bd1_0.issue_date,bd1_0.price,bd1_0.publish_date,bd1_0.return_date,bd1_0.subtitle,bd1_0.synposis from book_details bd1_0 where bd1_0.user_roll_no=?
2024-09-28T20:27:58.005+05:30 DEBUG 6724 --- [nio-8080-exec-1] o.s.w.s.v.ContentNegotiatingViewResolver : Selected 'text/html' given [text/html, application/xhtml+xml, image/avif, image/webp, image/apng, application/xml;q=0.9, */*;q=0.8, application/signed-exchange;v=b3;q=0.7]
2024-09-28T20:27:58.009+05:30 DEBUG 6724 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Completed 200 OK

llers.AdminController#studentAllBooks(Long, Model)
2024-09-28T20:27:57.996+05:30 DEBUG 6724 --- [nio-8080-exec-1] org.hibernate.SQL                        : select sd1_0.roll_no,sd1_0.email,sd1_0.name,sd1_0.phone_number from student_details sd1_0 where sd1_0.roll_no=?
Hibernate: select sd1_0.roll_no,sd1_0.email,sd1_0.name,sd1_0.phone_number from student_details sd1_0 where sd1_0.roll_no=?
2024-09-28T20:27:58.002+05:30 DEBUG 6724 --- [nio-8080-exec-1] org.hibernate.SQL                        : select bd1_0.user_roll_no,bd1_0.book_id,bd1_0.authors,bd1_0.book_name,bd1_0.book_pdf,bd1_0.currency_code,bd1_0.description,bd1_0.image,bd1_0.issue_date,bd1_0.price,bd1_0.publish_date,bd1_0.return_date,bd1_0.subtitle,bd1_0.synposis from book_details bd1_0 where bd1_0.user_roll_no=?
Hibernate: select bd1_0.user_roll_no,bd1_0.book_id,bd1_0.authors,bd1_0.book_name,bd1_0.book_pdf,bd1_0.currency_code,bd1_0.description,bd1_0.image,bd1_0.issue_date,bd1_0.price,bd1_0.publish_date,bd1_0.return_date,bd1_0.subtitle,bd1_0.synposis from book_details bd1_0 where bd1_0.user_roll_no=?
2024-09-28T20:27:58.005+05:30 DEBUG 6724 --- [nio-8080-exec-1] o.s.w.s.v.ContentNegotiatingViewResolver : Selected 'text/html' given [text/html, application/xhtml+xml, image/avif, image/webp, image/apng, application/xml;q=0.9, */*;q=0.8, application/signed-exchange;v=b3;q=0.7]
2024-09-28T20:27:58.009+05:30 DEBUG 6724 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet        : Completed 200 OK

@Override
    public Optional<StudentDetails> getStudentDetailsByIdForDeleting(Long roll_no) {
        Optional<StudentDetails> studentDetails = detailsRepository.findById(roll_no);
        if (studentDetails.isPresent()) {
            StudentDetails studentDetailsOptional = studentDetails.get();
            return Optional.of(studentDetailsOptional);
        }
        return Optional.empty();
    }

@Override
    public Optional<StudentDetails> getStudentDetailsByIdForDeleting(Long roll_no) {
        Optional<StudentDetails> studentDetails = detailsRepository.findById(roll_no);
        if (studentDetails.isPresent()) {
            StudentDetails studentDetailsOptional = studentDetails.get();
            return Optional.of(studentDetailsOptional);
        }
        return Optional.empty();
    }