Spring boot - blog application (REST API) : Validation @Valid

 

스프링 부트에서 유효성 검사를 해보려고 합니다.

Create, Update Post REST API 요청에 대해 유효성 검사

 

 

dependency 추가

<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-validation -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-validation</artifactId>
    <version>2.7.0</version>
</dependency>

 

 

PostDto 에 애노테이션 추가

package com.springboot.blog.payload;

@Data
public class PostDto 
{
	private long id;
	
	@NotEmpty
	@Size(min =2, message="Post title should have at least 2 characters")
	private String title;
	
	@NotEmpty
	@Size(min= 10, message="Post description should have at 10 characters")
	private String description;
	
	@NotEmpty
	private String content;
	
	private Set<CommentDto> comments;
}

 

@NotEmpty

The annotated element must not be null nor empty

String , Collection, Map, Array 에 적용

 

 

Controller에 적용

PostController

	@PostMapping
	public ResponseEntity<PostDto> createPost(@Valid @RequestBody PostDto postDto){
		return new ResponseEntity<>(postService.createPost(postDto),HttpStatus.CREATED);
	}

.

	// update post by id rest api
	@PutMapping("/{id}")
	public ResponseEntity<PostDto> updatePost(@Valid @RequestBody PostDto postDto, @PathVariable(name="id") long id){
		PostDto postResponse = postService.updatePost(postDto, id);
		return new ResponseEntity<>(postResponse,HttpStatus.OK);
		
	}

 

TEST

 

 

---

 

 

Customizing Validation Response

2022-07-03 08:14:25.582  WARN 8956 --- [nio-8080-exec-1] .m.m.a.ExceptionHandlerExceptionResolver : Resolved [org.springframework.web.bind.MethodArgumentNotValidException: Validation failed for argument [0] in public org.springframework.http.ResponseEntity<com.springboot.blog.payload.PostDto> com.springboot.blog.controller.PostController.createPost(com.springboot.blog.payload.PostDto): [Field error in object 'postDto' on field 'title': rejected value [g]; codes [Size.postDto.title,Size.title,Size.java.lang.String,Size]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [postDto.title,title]; arguments []; default message [title],2147483647,2]; default message [Post title should have at least 2 characters]] ]

MethodArgumentNotValidException 가 발생하는 것을 볼 수 있다.

 

 

GlobalExceptionHandler 에서 @ExceptionHandler 추가

GlobalExceptionHandler 

	//MethodArgumentNotValidException 
	@ExceptionHandler(MethodArgumentNotValidException .class)
	public ResponseEntity<Object> handleMethodArgumentNotValidException(MethodArgumentNotValidException  exception, WebRequest webRequest)
	{
		Map<String , String >errors= new HashMap<>();
		exception.getBindingResult().getAllErrors().forEach((error)->{
			String fieldName = ((FieldError) error).getField();
			String message = error.getDefaultMessage();
			errors.put(fieldName, message);
		});
		return new ResponseEntity<>(errors,HttpStatus.BAD_REQUEST);
	}

 

TEST

MethodArgumentNotValidException에 걸린 부분만 설정한 에러 메시지가 담겨오는 걸 볼 수 있다.

 

 

---

 

 

마찬가지로 Comment 에도 추가

CommentDto

package com.springboot.blog.payload;

@Data
public class CommentDto 
{
	private long id;
	@NotEmpty(message="Name should not be null or empty")
	private String name;
	@NotEmpty(message="Email should not be null or empty")
	@Email
	private String email;
	@NotEmpty
	@Size(min=10, message="Comment body must be mininum 10 characters")
	private String body;
}

 

CommentController

	@PostMapping("/posts/{postId}/comments")
	public ResponseEntity<CommentDto> createComment(
																				@PathVariable long postId,
																				@Valid @RequestBody CommentDto commentDto){
				return new ResponseEntity<>(commentService.createComment(postId, commentDto), HttpStatus.CREATED);
	}

.

	@PutMapping("/posts/{postId}/comments/{id}")
	public ResponseEntity<CommentDto> updateComment(@PathVariable Long postId, @PathVariable(value="id") Long commentId, 
					@Valid @RequestBody CommentDto commentDto)
	{
		return new ResponseEntity<>(commentService.updateComment(postId, commentId, commentDto), HttpStatus.OK);
	}