import java.util.List;

@Controllerpublic class BookController {

@Autowired private BookRepository bookRepository;

/** * Handles listing of all books and searching. * @param model * @return */ @GetMapping({"/index", "/search"}) public String showBooks(Model model, String keyword) { if (keyword != null) { model.addAttribute("books", this.bookRepository.findByTitleStartsWithOrAuthor(keyword, keyword)); model.addAttribute("keyword", keyword); } else { List books = this.bookRepository.findAll(); model.addAttribute("books", books); } return "index"; }

/** * Show form for adding a book document * @param book * @return */ @GetMapping("/add-book") public String showAddBookForm(Book book) { return "add-book"; }

/** * This will CREATE a books. C of CRUD. * @param book * @param result * @param model * @return */ @PostMapping("/add-book") public String addBook(Book book, BindingResult result, Model model) { if (result.hasErrors()) { return "add-book"; } this.bookRepository.save(book); return "redirect:/index"; }

/** * Show form for editing a book document. The R in CRUD. * @param id * @param model * @return */ @GetMapping("/edit-book/{id}") public String showUpdateForm(@PathVariable("id") String id, Model model) { Book book = this.bookRepository.findById(id).orElseThrow(() -> new IllegalArgumentException("Invalid book Id:" + id)); model.addAttribute("book", book);

return "edit-book"; }

/** * This will update a book document. The U in CRUD * @param id * @param book * @param result * @param model * @return */ @PostMapping("/edit-book/{id}") public String updateBook(@PathVariable("id") String id, Book book, BindingResult result, Model model) { if (result.hasErrors()) { book.setId(id); return "edit-book"; }

this.bookRepository.save(book);

return "redirect:/index"; }

/** * This will delete a book document. The D in CRUD. * @param id * @param model * @return */ @GetMapping("/delete-book/{id}") public String deleteUser(@PathVariable("id") String id, Model model) { Book book = this.bookRepository.findById(id).orElseThrow(() -> new IllegalArgumentException("Invalid book Id:" + id)); this.bookRepository.delete(book);

return "redirect:/index"; }}