Piszę sobie prostego cruda (spring boot, spring data, thymyleaf) i jestem na etapie że rekordy do bazy danych się dodają ale mam problem z wyciągnięciem ich do tabelki w html'u.

BookController

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PostMapping;

import java.util.List;

@Controller
public class BookController {
    private BookRepository bookRepository;

    @Autowired
    public BookController(BookRepository bookRepository) {
        this.bookRepository = bookRepository;
    }

    @PostMapping("/add")
    public String saveBook(@ModelAttribute Book book) {
        bookRepository.save(book);
        return "redirect:/";
    }

    @GetMapping("/show")
    public String showall(Model model) {
        List<Book> allBooks = bookRepository.findAll();
        model.addAttribute("allBooks",  allBooks);
        return "showall";
    }
}

ShowAllController

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;

@Controller
public class ShowAllController {
    @GetMapping("/showall")
    public String showall() {
        return "showall";
    }
}

showall.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8" />
    <title>All results</title>
</head>
<body>
 <h1>Books:</h1>
    <table  border="1">
        <tr>
            <th>Isbn</th>
            <th>Title</th>
            <th>Author</th>
            <th>Publisher</th>
            <th>Release year</th>
        </tr>
        <tr th:each="book: ${allBooks}">
            <td th:number="${book.isbn}"/>
            <td th:text="${book.title}"/>
            <td th:text="${book.author}"/>
            <td th:text="${book.publisher}"/>
            <td th:number="${book.releaseYear}"/>
        </tr>
    </table>
 <a th:href="@{/add}">Add book</a>
</body>
</html>

Gdzieś tu jest problem z listą?

Update:
Problem rozwiązany:

show.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8" />
    <title>All results</title>
</head>
<body>
<div th:if="${!#lists.isEmpty(allBooks)}">
    <h1>All registered books:</h1>
     <table border="1">
         <tr>
             <th>Id</th>
             <th>Isbn</th>
             <th>Title</th>
             <th>Author</th>
             <th>Publisher</th>
             <th>Release year</th>
         </tr>
         <tr th:each="book : ${allBooks}" th:object="${Book}">
             <td th:text="${book.id}">id</td>
             <td th:text="${book.isbn}">isbn</td>
             <td th:text="${book.title}">Tytuł</td>
             <td th:text="${book.author}">Autor</td>
             <td th:text="${book.publisher}">Wydawca</td>
             <td th:text="${book.releaseYear}">Rok wydania</td>
         </tr>
     </table>
</div>
     <div th:if="${#lists.isEmpty(allBooks)}">
         <h1>Brak książek w bazie.(</h1>
     </div>
<a th:href="@{/add}">Add book</a><br>
<a th:href="@{/show}">Show all books</a><br>
<a th:href="@{/update}">Update books</a><br>
<a th:href="@{/delete}">Delete book/books</a><br>
</body>
</html>

BookController


import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;

import java.util.List;

@Controller
public class BookController {

    private BookRepository bookRepository;

    @Autowired
    public BookController(BookRepository bookRepository) {
        this.bookRepository = bookRepository;
    }

    @GetMapping("/")
    public String index() {
        return "index";
    }

    @PostMapping("/add")
    public String saveBook(Book book) {
        bookRepository.save(book);
        return "add";
    }

    @GetMapping("/show")
    public String showall(Model model) {
        List<Book> allBooks = bookRepository.findAll();
        model.addAttribute("allBooks", allBooks);
        return "show";
    }

    @PostMapping("/update")
    public String update(Book book, Long id) {
        Book bookToUpdate = bookRepository.getOne(id);
        bookToUpdate.setIsbn(book.getIsbn());
        bookToUpdate.setTitle(book.getTitle());
        bookToUpdate.setAuthor(book.getAuthor());
        bookToUpdate.setPublisher(book.getPublisher());
        bookToUpdate.setReleaseYear(book.getReleaseYear());
        bookRepository.save(bookToUpdate);
        return "redirect:/";

    }

    @PostMapping("/delete")
    public String deleteBook() {
        bookRepository.deleteAll();
        return "delete";
    }

}```