Improvements & Refactoring

build.gradle

@@ -21,6 +21,7 @@ repositories {
 dependencies {
     implementation 'org.springframework.boot:spring-boot-starter-data-mongodb'
     implementation 'org.springframework.boot:spring-boot-starter-web'
+    implementation 'javax.validation:validation-api:2.0.1.Final'
     compileOnly 'org.projectlombok:lombok'
     annotationProcessor 'org.projectlombok:lombok'
     testImplementation('org.springframework.boot:spring-boot-starter-test') {

src/main/java/com/javatodev/api/controller/LibraryController.java

@@ -8,21 +8,23 @@
 import com.javatodev.api.model.request.BookLendRequest;
 import com.javatodev.api.model.request.MemberCreationRequest;
 import com.javatodev.api.service.LibraryService;
-
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
+import org.springframework.validation.annotation.Validated;
 import org.springframework.web.bind.annotation.*;
 
+import javax.validation.Valid;
 import java.util.List;
 
-import lombok.RequiredArgsConstructor;
-
+@Validated
 @RestController
 @RequestMapping(value = "/api/library")
 @RequiredArgsConstructor
 public class LibraryController {
     private final LibraryService libraryService;
 
-    @GetMapping("/book")
+    @GetMapping("/books")
     public ResponseEntity readBooks(@RequestParam(required = false) String isbn) {
         if (isbn == null) {
             return ResponseEntity.ok(libraryService.readBooks());
@@ -31,48 +33,51 @@ public ResponseEntity readBooks(@RequestParam(required = false) String isbn) {
     }
 
     @GetMapping("/book/{bookId}")
-    public ResponseEntity<Book> readBook (@PathVariable String bookId) {
+    public ResponseEntity<Book> readBook(@PathVariable String bookId) {
         return ResponseEntity.ok(libraryService.readBookById(bookId));
     }
 
     @PostMapping("/book")
-    public ResponseEntity<Book> createBook (@RequestBody BookCreationRequest request) {
+    @ResponseStatus(HttpStatus.CREATED)
+    public ResponseEntity<Book> createBook(@RequestBody @Valid BookCreationRequest request) {
         return ResponseEntity.ok(libraryService.createBook(request));
     }
 
     @PatchMapping("/book/{bookId}")
-    public ResponseEntity<Book> updateBook (@PathVariable("bookId") String bookId, @RequestBody BookCreationRequest request) {
+    public ResponseEntity<Book> updateBook(@PathVariable("bookId") String bookId, @RequestBody BookCreationRequest request) {
         return ResponseEntity.ok(libraryService.updateBook(bookId, request));
     }
 
     @PostMapping("/author")
-    public ResponseEntity<Author> createAuthor (@RequestBody AuthorCreationRequest request) {
+    @ResponseStatus(HttpStatus.CREATED)
+    public ResponseEntity<Author> createAuthor(@RequestBody @Valid AuthorCreationRequest request) {
         return ResponseEntity.ok(libraryService.createAuthor(request));
     }
 
     @DeleteMapping("/book/{bookId}")
-    public ResponseEntity<Void> deleteBook (@PathVariable String bookId) {
+    public ResponseEntity<Void> deleteBook(@PathVariable String bookId) {
         libraryService.deleteBook(bookId);
         return ResponseEntity.ok().build();
     }
 
     @PostMapping("/member")
-    public ResponseEntity<Member> createMember (@RequestBody MemberCreationRequest request) {
+    @ResponseStatus(HttpStatus.CREATED)
+    public ResponseEntity<Member> createMember(@RequestBody @Valid MemberCreationRequest request) {
         return ResponseEntity.ok(libraryService.createMember(request));
     }
 
-    @GetMapping("/member")
-    public ResponseEntity<List<Member>> readMembers () {
+    @GetMapping("/members")
+    public ResponseEntity<List<Member>> readMembers() {
         return ResponseEntity.ok(libraryService.readMembers());
     }
 
     @PatchMapping("/member/{memberId}")
-    public ResponseEntity<Member> updateMember (@RequestBody MemberCreationRequest request, @PathVariable String memberId) {
+    public ResponseEntity<Member> updateMember(@RequestBody @Valid MemberCreationRequest request, @PathVariable String memberId) {
         return ResponseEntity.ok(libraryService.updateMember(memberId, request));
     }
 
     @PostMapping("/book/lend")
-    public ResponseEntity<List<String>> lendABook(@RequestBody BookLendRequest bookLendRequests) {
+    public ResponseEntity<List<String>> lendABook(@RequestBody @Valid BookLendRequest bookLendRequests) {
         return ResponseEntity.ok(libraryService.lendABook(bookLendRequests));
     }
 }

src/main/java/com/javatodev/api/exception/EntityNotFoundException.java

@@ -1,7 +1,7 @@
 package com.javatodev.api.exception;
 
 public class EntityNotFoundException extends RuntimeException {
-    public EntityNotFoundException(String message) {
-        super(message);
+    public EntityNotFoundException(String document) {
+        super("Related " + document + " not found.");
     }
 }

src/main/java/com/javatodev/api/exception/GenericExceptionHandler.java

@@ -0,0 +1,35 @@
+package com.javatodev.api.exception;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+
+import java.util.HashMap;
+import java.util.Map;
+
+@ControllerAdvice
+public class GenericExceptionHandler {
+
+    @ExceptionHandler(EntityNotFoundException.class)
+    public ResponseEntity<Map> handleNotfoundException(EntityNotFoundException exception) {
+        return ResponseEntity.status(HttpStatus.NOT_FOUND).body(prepareResponse(exception.getMessage()));
+    }
+
+    @ExceptionHandler(InvalidMemberStatusException.class)
+    public ResponseEntity<Map> handleInvalidMemberStatusException(InvalidMemberStatusException exception) {
+        return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(prepareResponse(exception.getMessage()));
+    }
+
+    @ExceptionHandler(Exception.class)
+    public ResponseEntity<Map> handleException(Exception exception) {
+        return ResponseEntity.status(HttpStatus.SERVICE_UNAVAILABLE).body(prepareResponse(exception.getMessage()));
+    }
+
+    // Response message can be detailed here
+    private Map<String, String> prepareResponse(String message) {
+        Map<String, String> response = new HashMap<>();
+        response.put("message", message);
+        return response;
+    }
+}

src/main/java/com/javatodev/api/exception/InvalidMemberStatusException.java

@@ -0,0 +1,7 @@
+package com.javatodev.api.exception;
+
+public class InvalidMemberStatusException extends RuntimeException {
+    public InvalidMemberStatusException(String message) {
+        super(message);
+    }
+}

src/main/java/com/javatodev/api/model/Author.java

@@ -1,17 +1,15 @@
 package com.javatodev.api.model;
 
+import lombok.Data;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.mongodb.core.mapping.Document;
 
-import lombok.Getter;
-import lombok.Setter;
-
-@Getter
-@Setter
+@Data
 @Document
 public class Author {
     @Id
     private String id;
     private String firstName;
     private String lastName;
+
 }

src/main/java/com/javatodev/api/model/Book.java

@@ -1,14 +1,11 @@
 package com.javatodev.api.model;
 
+import lombok.Data;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.mongodb.core.mapping.DBRef;
 import org.springframework.data.mongodb.core.mapping.Document;
 
-import lombok.Getter;
-import lombok.Setter;
-
-@Getter
-@Setter
+@Data
 @Document
 public class Book {
 

src/main/java/com/javatodev/api/model/Lend.java

@@ -1,18 +1,13 @@
 package com.javatodev.api.model;
 
+import lombok.Data;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.mongodb.core.mapping.DBRef;
 import org.springframework.data.mongodb.core.mapping.Document;
 
 import java.time.Instant;
 
-import lombok.Builder;
-import lombok.Getter;
-import lombok.NoArgsConstructor;
-import lombok.Setter;
-
-@Getter
-@Setter
+@Data
 @Document
 public class Lend {
 

src/main/java/com/javatodev/api/model/LendStatus.java

@@ -1,5 +1,5 @@
 package com.javatodev.api.model;
 
 public enum LendStatus {
-    AVAILABLE, BURROWED
+    AVAILABLE, BORROWED
 }

src/main/java/com/javatodev/api/model/Member.java

@@ -1,14 +1,10 @@
 package com.javatodev.api.model;
 
+import lombok.Data;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.mongodb.core.mapping.Document;
 
-import lombok.Builder;
-import lombok.Getter;
-import lombok.Setter;
-
-@Getter
-@Setter
+@Data
 @Document
 public class Member {
 

src/main/java/com/javatodev/api/model/request/AuthorCreationRequest.java

@@ -2,8 +2,12 @@
 
 import lombok.Data;
 
+import javax.validation.constraints.NotBlank;
+
 @Data
 public class AuthorCreationRequest {
+    @NotBlank
     private String firstName;
+    @NotBlank
     private String lastName;
 }

src/main/java/com/javatodev/api/model/request/BookCreationRequest.java

@@ -2,9 +2,14 @@
 
 import lombok.Data;
 
+import javax.validation.constraints.NotBlank;
+
 @Data
 public class BookCreationRequest {
+    @NotBlank
     private String name;
+    @NotBlank
     private String isbn;
+    @NotBlank
     private String authorId;
-}
+}

src/main/java/com/javatodev/api/model/request/BookLendRequest.java

@@ -1,11 +1,15 @@
 package com.javatodev.api.model.request;
 
-import java.util.List;
-
 import lombok.Data;
 
+import javax.validation.constraints.NotBlank;
+import javax.validation.constraints.NotEmpty;
+import java.util.List;
+
 @Data
 public class BookLendRequest {
+    @NotEmpty
     private List<String> bookIds;
+    @NotBlank
     private String memberId;
 }

src/main/java/com/javatodev/api/model/request/MemberCreationRequest.java

@@ -2,8 +2,12 @@
 
 import lombok.Data;
 
+import javax.validation.constraints.NotBlank;
+
 @Data
 public class MemberCreationRequest {
+    @NotBlank
     private String firstName;
+    @NotBlank
     private String lastName;
-}
+}