Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@src/main/java/org/example/lab1springboot/controller/BookController.java`:
- Around line 75-79: The showUpdateForm method in BookController currently adds
only "book" to the model but the template expects "updateBookDTO" and "id";
change showUpdateForm (which calls bookService.getBookById) to map the retrieved
Book into an UpdateBookDTO instance, add model.addAttribute("updateBookDTO",
updateDto) and model.addAttribute("id", id) (or model.addAttribute("id",
book.getId())), so the template can bind to ${updateBookDTO} and ${id}; use the
UpdateBookDTO constructor or setters to populate fields from Book before
returning "update-book".

In `@src/main/java/org/example/lab1springboot/controller/UserController.java`:
- Around line 12-15: The CreateUser(`@RequestBody` `@Valid` User user) handler in
UserController returns the view name "user" which doesn't exist in the templates
and will fail view resolution; fix by either creating a new user.html template
matching that view name or changing the handler to return an existing view
(e.g., "home") or a redirect (e.g., "redirect:/home") after successful
creation—update the method in UserController (CreateUser) accordingly so the
returned view name matches an actual template or uses redirect to an existing
route.
- Around line 4-13: The controller is importing Tomcat's
org.apache.catalina.User instead of your application POJO, causing
deserialization to fail; update the import in UserController to use your
application's model (org.example.lab1springboot.user.User) so the `@RequestBody`
`@Valid` User user parameter refers to a concrete class, then ensure the
CreateUser method and class-level imports no longer reference
org.apache.catalina.User.

In `@src/main/java/org/example/lab1springboot/GlobalExceptionHandler.java`:
- Around line 19-24: The handler GlobalExceptionHandler.handleRuntimeException
returns the view name "error" and adds the "errorMessage" model attribute, but
there is no corresponding error template; create a new "error" template in the
templates set that displays the errorMessage (and optionally reuses navbar or
layout fragments) so that returning "error" resolves to a user-facing page
instead of causing view-resolution failure.
- Around line 19-24: The handler method in GlobalExceptionHandler —
handleRuntimeException(RuntimeException, Model) — returns an error view but
doesn't set an HTTP status; add the
`@ResponseStatus`(HttpStatus.INTERNAL_SERVER_ERROR) annotation to that method (and
import ResponseStatus and HttpStatus) so the response returns 500 instead of 200
when a RuntimeException is handled.

In `@src/main/java/org/example/lab1springboot/user/User.java`:
- Around line 26-27: The User model currently requires a client-supplied id via
the `@NotNull` annotation on the id field which prevents normal server-side ID
generation for POST /user; remove the `@NotNull` on the id field in class User (or
better: introduce a CreateUser DTO without an id and validate that instead) and
ensure ID is assigned server-side in the controller/service that handles POST
/user (refer to User.id, the `@NotNull` annotation, and the POST /user flow when
making the change).
- Around line 13-21: The validation annotations on User fields allow
blank/whitespace values; replace `@NotNull/`@NotEmpty with `@NotBlank` on the name,
username, and email fields (i.e., the private String name, private String
username, private String email in class User) to reject empty or whitespace-only
input, and add `@Email` to the email field to enforce proper email format; keep
the message attributes (or adjust them) when updating the annotations so
validation messages remain informative.

In `@src/main/resources/templates/create-book.html`:
- Around line 10-18: The create-book template is missing the form bound to the
CreateBookDTO expected by BookController.createBook; add an HTML <form> in
create-book.html that uses Thymeleaf binding (th:object="${book}"), includes
inputs bound to the DTO properties (e.g., th:field for title, author, isbn,
etc.), and posts to the controller endpoint (the action that
BookController.createBook handles) with a submit button so the controller
receives a populated CreateBookDTO.

In `@src/main/resources/templates/home.html`:
- Around line 13-14: The template uses ${message} and ${currentDate} but
HomeController.home() only adds activePage, so those bindings will be empty; fix
by either (A) adding model attributes in HomeController.home(): put
model.addAttribute("message", "<desired text>") and
model.addAttribute("currentDate", LocalDate.now() or formatted date) so the
th:text bindings have backing data, or (B) revert the template to static content
by replacing <h1 th:text="${message}"> and <span th:text="${currentDate}"> with
plain text values; update the HomeController.home() method or the <h1>/<span>
elements accordingly.

In `@src/main/resources/templates/navbar.html`:
- Around line 6-10: The navbar stylesheet link is outside the exported fragment,
so pages that replace the node with the header fragment (th:fragment="navbar")
lose the CSS; move the <link th:href="@{/css/navbar.css}" rel="stylesheet"> into
the fragment (inside the header element defined by th:fragment="navbar") or
alternatively change the fragment to include a head fragment that injects the
stylesheet so that consumers of the header fragment (navbar) automatically get
the /css/navbar.css without needing to add it manually; update the template
around th:fragment="navbar" and the existing <link th:href...> accordingly.

In `@src/main/resources/templates/update-book.html`:
- Around line 14-17: The form in update-book.html currently has the title/author
input fields commented out so the Update Book button submits no editable data;
restore the inputs by uncommenting or re-adding the input elements that bind to
the model (the lines using th:field="*{title}" and th:field="*{author}") so the
form includes the title and author values on submit, ensuring they remain inside
the same <form> as the <button type="submit"> and keep any required attributes
(e.g., id/name or th:field) consistent with the backing model.

---

Outside diff comments:
In `@src/main/java/org/example/lab1springboot/controller/BookController.java`:
- Around line 57-79: The controller routes for edit/delete are missing the
"/books" prefix; update the BookController routing so the template URLs
(/books/update/{id} and /books/{id}) match the handlers: add a class-level
`@RequestMapping`("/books") annotation to the BookController class (so methods
updateBook, deleteBook, and showUpdateForm keep their current
`@PutMapping/`@DeleteMapping/@GetMapping paths) or alternatively prefix each
method mapping with "/books" to ensure consistent routing.

---

Nitpick comments:
In `@src/main/java/org/example/lab1springboot/book/CreateBookDTO.java`:
- Around line 8-15: The class CreateBookDTO uses both `@Getter/`@Setter and `@Data`
which is redundant and expands the API (adding equals/hashCode/toString); remove
the `@Data` annotation and its import (lombok.Data) and keep only `@Getter` and
`@Setter` on CreateBookDTO so the DTO only generates accessors and not the
additional methods.

In `@src/main/java/org/example/lab1springboot/controller/BookController.java`:
- Around line 37-42: The getBooks handler in BookController currently accepts a
title param but always returns bookService.getAllBooks(), so either apply the
title filter or remove the param: if you want filtering, modify
BookController.getBooks to call the service filtering method (e.g.,
bookService.findByTitle(title) or bookService.getBooksFilteredByTitle(title))
when title is non-empty and put that result into model.addAttribute("books",
...); if your service lacks a filter method add one (e.g., in BookService
implement findByTitle or filter the list returned by getAllBooks()), and ensure
null/empty title falls back to getAllBooks(); alternatively, remove the
`@RequestParam`(required = false) String title from the getBooks signature and any
callers expecting that query param.

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@src/main/java/org/example/lab1springboot/controller/BookController.java`:
- Around line 57-58: The route annotations in BookController (e.g., updateBook)
don't match the URLs used by the templates (/books/update/{id} and posts to
/books/{id}), causing 404s; update the mapping annotations so they are prefixed
with /books (for example change `@PutMapping`("/{id}") to
`@PutMapping`("/books/{id}") and any `@GetMapping` for the edit form to
`@GetMapping`("/books/update/{id}")), and likewise adjust the delete handler
mapping (e.g., deleteBook) to `@PostMapping` or `@DeleteMapping`("/books/{id}") as
the template expects; update the annotations on the methods named updateBook,
deleteBook (and the edit form handler, if present) so the controller paths and
templates are consistent.
- Around line 101-107: Validate the paging parameters in the controller before
calling bookService.getAllBooksPaginated: in getAllBooks check that page >= 0
and size >= 1 and if not throw a client error (e.g., throw new
ResponseStatusException(HttpStatus.BAD_REQUEST, "page must be >= 0 and size must
be >= 1")) so a bad query string yields HTTP 400 instead of allowing
PageRequest.of(page, size) (or any similar call inside
bookService.getAllBooksPaginated) to throw a 500.

In `@src/main/resources/templates/error.html`:
- Line 7: The template contains a malformed HTML tag '<<body>' which breaks
markup; open the template and replace the incorrect '<<body>' token with a
proper '<body>' start tag and ensure there is a matching '</body>' closing tag
(verify surrounding template logic around the body element) so the document
structure is valid.
- Around line 10-11: The template hardcodes "404" causing wrong status display;
change the <h1> to render a status placeholder (e.g., use the template engine's
expression like ${status}) instead of the literal "404", and ensure
GlobalExceptionHandler populates that model attribute when returning the error
view (update the methods in GlobalExceptionHandler to add a "status" attribute
with the actual HTTP status code before returning the template).
- Around line 14-16: The template only displays errorMessage and thus ignores
validation details placed by
GlobalExceptionHandler.handleMethodArgumentNotValidException under the "errors"
model attribute; update the error.html to also render the "errors" collection
(e.g., check if errors exists and iterate to show each field/message) in
addition to the existing errorMessage so validation failures surface the actual
field-level messages.

---

Duplicate comments:
In `@src/main/java/org/example/lab1springboot/controller/BookController.java`:
- Around line 77-83: The UpdateBookDTO is created empty after loading the book
in BookController (bookService.getBookById(id)) so the edit form shows no
current values; populate the DTO fields from the loaded Book (e.g., title,
author, etc.) before calling model.addAttribute("updateBookDTO", dto) and keep
adding the id as before so the form is pre-filled with the book's existing data.

---

Nitpick comments:
In `@src/main/java/org/example/lab1springboot/controller/BookController.java`:
- Around line 94-99: Remove the duplicate BookNotFoundException handler method
from BookController: delete the handleBookNotFound(BookNotFoundException ex,
Model model) method so the application uses the centralized
GlobalExceptionHandler (which already handles BookNotFoundException and returns
the 404/error view). After removal, clean up any now-unused imports in
BookController and run tests to ensure no references remain.