refactor: migrate validations from services to controllers

.vscode/settings.json

@@ -5,7 +5,8 @@
   "editor.detectIndentation": false,
   "editor.formatOnSave": true,
   "[java]": {
-    "editor.defaultFormatter": "redhat.java"
+    "editor.defaultFormatter": "redhat.java",
+    "editor.inlayHints.enabled": "off"
   },
   "java.configuration.updateBuildConfiguration": "automatic",
   "java.compile.nullAnalysis.mode": "automatic",

src/main/java/ar/com/nanotaboada/java/samples/spring/boot/controllers/BooksController.java

@@ -1,9 +1,13 @@
 package ar.com.nanotaboada.java.samples.spring.boot.controllers;
 
+import static org.springframework.http.HttpHeaders.LOCATION;
+
 import java.net.URI;
 import java.util.List;
 
-import org.springframework.http.HttpHeaders;
+import jakarta.validation.Valid;
+
+import org.hibernate.validator.constraints.ISBN;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.DeleteMapping;
@@ -25,6 +29,7 @@
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
 import io.swagger.v3.oas.annotations.responses.ApiResponses;
 import io.swagger.v3.oas.annotations.tags.Tag;
+
 import ar.com.nanotaboada.java.samples.spring.boot.models.BookDTO;
 import ar.com.nanotaboada.java.samples.spring.boot.services.BooksService;
 
@@ -52,22 +57,18 @@ public BooksController(BooksService booksService) {
             @ApiResponse(responseCode = "400", description = "Bad Request", content = @Content),
             @ApiResponse(responseCode = "409", description = "Conflict", content = @Content)
     })
-    public ResponseEntity<String> post(@RequestBody BookDTO bookDTO) {
-        if (booksService.retrieveByIsbn(bookDTO.getIsbn()) != null) {
-            return new ResponseEntity<>(HttpStatus.CONFLICT);
-        } else {
-            if (booksService.create(bookDTO)) {
-                URI location = MvcUriComponentsBuilder
-                        .fromMethodName(BooksController.class, "getByIsbn", bookDTO.getIsbn())
-                        .build()
-                        .toUri();
-                HttpHeaders httpHeaders = new HttpHeaders();
-                httpHeaders.setLocation(location);
-                return new ResponseEntity<>(httpHeaders, HttpStatus.CREATED);
-            } else {
-                return new ResponseEntity<>(HttpStatus.BAD_REQUEST);
-            }
+    public ResponseEntity<Void> post(@RequestBody @Valid BookDTO bookDTO) {
+        boolean created = booksService.create(bookDTO);
+        if (!created) {
+            return ResponseEntity.status(HttpStatus.CONFLICT).build();
         }
+        URI location = MvcUriComponentsBuilder
+                .fromMethodCall(MvcUriComponentsBuilder.on(BooksController.class).getByIsbn(bookDTO.getIsbn()))
+                .build()
+                .toUri();
+        return ResponseEntity.status(HttpStatus.CREATED)
+                .header(LOCATION, location.toString())
+                .build();
     }
 
     /*
@@ -77,18 +78,16 @@ public ResponseEntity<String> post(@RequestBody BookDTO bookDTO) {
      */
 
     @GetMapping("/books/{isbn}")
-    @Operation(summary = "Retrieves a book by its ID")
+    @Operation(summary = "Retrieves a book by its ISBN")
     @ApiResponses(value = {
             @ApiResponse(responseCode = "200", description = "OK", content = @Content(mediaType = "application/json", schema = @Schema(implementation = BookDTO.class))),
             @ApiResponse(responseCode = "404", description = "Not Found", content = @Content)
     })
     public ResponseEntity<BookDTO> getByIsbn(@PathVariable String isbn) {
         BookDTO bookDTO = booksService.retrieveByIsbn(isbn);
-        if (bookDTO != null) {
-            return new ResponseEntity<>(bookDTO, HttpStatus.OK);
-        } else {
-            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
-        }
+        return (bookDTO != null)
+                ? ResponseEntity.status(HttpStatus.OK).body(bookDTO)
+                : ResponseEntity.status(HttpStatus.NOT_FOUND).build();
     }
 
     @GetMapping("/books")
@@ -98,7 +97,7 @@ public ResponseEntity<BookDTO> getByIsbn(@PathVariable String isbn) {
     })
     public ResponseEntity<List<BookDTO>> getAll() {
         List<BookDTO> books = booksService.retrieveAll();
-        return new ResponseEntity<>(books, HttpStatus.OK);
+        return ResponseEntity.status(HttpStatus.OK).body(books);
     }
 
     /*
@@ -108,22 +107,17 @@ public ResponseEntity<List<BookDTO>> getAll() {
      */
 
     @PutMapping("/books")
-    @Operation(summary = "Updates (entirely) a book by its ID")
+    @Operation(summary = "Updates (entirely) a book by its ISBN")
     @ApiResponses(value = {
             @ApiResponse(responseCode = "204", description = "No Content", content = @Content),
             @ApiResponse(responseCode = "400", description = "Bad Request", content = @Content),
             @ApiResponse(responseCode = "404", description = "Not Found", content = @Content)
     })
-    public ResponseEntity<String> put(@RequestBody BookDTO bookDTO) {
-        if (booksService.retrieveByIsbn(bookDTO.getIsbn()) != null) {
-            if (booksService.update(bookDTO)) {
-                return new ResponseEntity<>(HttpStatus.NO_CONTENT);
-            } else {
-                return new ResponseEntity<>(HttpStatus.BAD_REQUEST);
-            }
-        } else {
-            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
-        }
+    public ResponseEntity<Void> put(@RequestBody @Valid BookDTO bookDTO) {
+        boolean updated = booksService.update(bookDTO);
+        return (updated)
+                ? ResponseEntity.status(HttpStatus.NO_CONTENT).build()
+                : ResponseEntity.status(HttpStatus.NOT_FOUND).build();
     }
 
     /*
@@ -133,21 +127,16 @@ public ResponseEntity<String> put(@RequestBody BookDTO bookDTO) {
      */
 
     @DeleteMapping("/books/{isbn}")
-    @Operation(summary = "Deletes a book by its ID")
+    @Operation(summary = "Deletes a book by its ISBN")
     @ApiResponses(value = {
             @ApiResponse(responseCode = "204", description = "No Content", content = @Content),
             @ApiResponse(responseCode = "400", description = "Bad Request", content = @Content),
             @ApiResponse(responseCode = "404", description = "Not Found", content = @Content)
     })
-    public ResponseEntity<String> delete(@PathVariable String isbn) {
-        if (booksService.retrieveByIsbn(isbn) != null) {
-            if (booksService.delete(isbn)) {
-                return new ResponseEntity<>(HttpStatus.NO_CONTENT);
-            } else {
-                return new ResponseEntity<>(HttpStatus.BAD_REQUEST);
-            }
-        } else {
-            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
-        }
+    public ResponseEntity<Void> delete(@PathVariable @ISBN String isbn) {
+        boolean deleted = booksService.delete(isbn);
+        return (deleted)
+                ? ResponseEntity.status(HttpStatus.NO_CONTENT).build()
+                : ResponseEntity.status(HttpStatus.NOT_FOUND).build();
     }
 }

src/main/java/ar/com/nanotaboada/java/samples/spring/boot/services/BooksService.java

@@ -1,11 +1,10 @@
 package ar.com.nanotaboada.java.samples.spring.boot.services;
 
-import jakarta.validation.Validator;
-import lombok.RequiredArgsConstructor;
-
 import java.util.List;
 import java.util.stream.StreamSupport;
 
+import lombok.RequiredArgsConstructor;
+
 import org.modelmapper.ModelMapper;
 import org.springframework.cache.annotation.CacheEvict;
 import org.springframework.cache.annotation.CachePut;
@@ -21,7 +20,6 @@
 public class BooksService {
 
     private final BooksRepository booksRepository;
-    private final Validator validator;
     private final ModelMapper modelMapper;
 
     /*
@@ -32,14 +30,14 @@ public class BooksService {
 
     @CachePut(value = "books", key = "#bookDTO.isbn")
     public boolean create(BookDTO bookDTO) {
-        boolean notExists = !booksRepository.existsById(bookDTO.getIsbn());
-        boolean valid = validator.validate(bookDTO).isEmpty();
-        if (notExists && valid) {
+        if (booksRepository.existsById(bookDTO.getIsbn())) {
+            return false;
+        } else {
             Book book = mapFrom(bookDTO);
             booksRepository.save(book);
             return true;
         }
-        return false;
+
     }
 
     /*
@@ -70,14 +68,13 @@ public List<BookDTO> retrieveAll() {
 
     @CachePut(value = "books", key = "#bookDTO.isbn")
     public boolean update(BookDTO bookDTO) {
-        boolean exists = booksRepository.existsById(bookDTO.getIsbn());
-        boolean valid = validator.validate(bookDTO).isEmpty();
-        if (exists && valid) {
+        if (booksRepository.existsById(bookDTO.getIsbn())) {
             Book book = mapFrom(bookDTO);
             booksRepository.save(book);
             return true;
+        } else {
+            return false;
         }
-        return false;
     }
 
     /*
@@ -91,8 +88,9 @@ public boolean delete(String isbn) {
         if (booksRepository.existsById(isbn)) {
             booksRepository.deleteById(isbn);
             return true;
+        } else {
+            return false;
         }
-        return false;
     }
 
     private BookDTO mapFrom(Book book) {

src/test/java/ar/com/nanotaboada/java/samples/spring/boot/test/BookDTOsBuilder.java → src/test/java/ar/com/nanotaboada/java/samples/spring/boot/test/BookDTOFakes.java

@@ -6,9 +6,13 @@
 
 import ar.com.nanotaboada.java.samples.spring.boot.models.BookDTO;
 
-public class BookDTOsBuilder {
+public final class BookDTOFakes {
 
-    public static BookDTO buildOneValid() {
+    private BookDTOFakes() {
+        throw new UnsupportedOperationException("This is a utility class and cannot be instantiated");
+    }
+
+    public static BookDTO createOneValid() {
         BookDTO bookDTO = new BookDTO();
         bookDTO.setIsbn("978-1484200773");
         bookDTO.setTitle("Pro Git");
@@ -28,7 +32,7 @@ Pro Git (Second Edition) is your fully-updated guide to Git and its \
         return bookDTO;
     }
 
-    public static BookDTO buildOneInvalid() {
+    public static BookDTO createOneInvalid() {
         BookDTO bookDTO = new BookDTO();
         bookDTO.setIsbn("978-1234567890"); // Invalid (invalid ISBN)
         bookDTO.setTitle("Title");
@@ -42,7 +46,7 @@ public static BookDTO buildOneInvalid() {
         return bookDTO;
     }
 
-    public static List<BookDTO> buildManyValid() {
+    public static List<BookDTO> createManyValid() {
         ArrayList<BookDTO> bookDTOs = new ArrayList<>();
         BookDTO bookDTO9781838986698 = new BookDTO();
         bookDTO9781838986698.setIsbn("9781838986698");

src/test/java/ar/com/nanotaboada/java/samples/spring/boot/test/BooksBuilder.java → src/test/java/ar/com/nanotaboada/java/samples/spring/boot/test/BookFakes.java

@@ -6,9 +6,13 @@
 
 import ar.com.nanotaboada.java.samples.spring.boot.models.Book;
 
-public class BooksBuilder {
+public final class BookFakes {
 
-    public static Book buildOneValid() {
+    private BookFakes() {
+        throw new UnsupportedOperationException("This is a utility class and cannot be instantiated");
+    }
+
+    public static Book createOneValid() {
         Book book = new Book();
         book.setIsbn("9781484200773");
         book.setTitle("Pro Git");
@@ -28,7 +32,7 @@ Pro Git (Second Edition) is your fully-updated guide to Git and its \
         return book;
     }
 
-    public static Book buildOneInvalid() {
+    public static Book createOneInvalid() {
         Book book = new Book();
         book.setIsbn("9781234567890"); // Invalid (invalid ISBN)
         book.setTitle("Title");
@@ -42,7 +46,7 @@ public static Book buildOneInvalid() {
         return book;
     }
 
-    public static List<Book> buildManyValid() {
+    public static List<Book> createManyValid() {
         ArrayList<Book> books = new ArrayList<>();
         Book book9781838986698 = new Book();
         book9781838986698.setIsbn("9781838986698");