Java Community | Help. Code. Learn.•2y ago

Spring Boot MVC: validate a multipart/form-data RequestBody

Hello! I have the need to fill a form with some meta data and a file. The meta data required fields depends on the media "type" that you're selecting from a drop-down. I've thus created a custom validator, associated to a custom annotation and put all on the PostMapping action annotating the parameter with @Valid @MyCustomAnnotation (see below). The thing is that the validator is not being called for a reason beyond my knowledge. May you please help me understand what I'm doing wrong? Thank you very much 🙂 The DTO + validator:

@Data
public class CreateMediaRequestResource {
    private MediaType mediaType;
    // TODO: various attributes depending on mediaType
    private MultipartFile media;

    @Documented
    @Constraint(validatedBy = CreateMediaRequestValidator.class)
    @Target({ElementType.PARAMETER})
    @Retention(RetentionPolicy.RUNTIME)
    public @interface CreateMediaRequestValidation {
        public String message() default "";
        public Class<?>[] groups() default {};
        public Class<? extends Payload>[] payload() default {};
    }

    @Component
    public class CreateMediaRequestValidator implements ConstraintValidator<CreateMediaRequestValidation, CreateMediaRequestResource> {
        @Override
        public boolean isValid(CreateMediaRequestResource value, ConstraintValidatorContext context) {
            System.out.println(value);
            System.out.println(context);

            return false;
        }}
}

@Data
public class CreateMediaRequestResource {
    private MediaType mediaType;
    // TODO: various attributes depending on mediaType
    private MultipartFile media;

    @Documented
    @Constraint(validatedBy = CreateMediaRequestValidator.class)
    @Target({ElementType.PARAMETER})
    @Retention(RetentionPolicy.RUNTIME)
    public @interface CreateMediaRequestValidation {
        public String message() default "";
        public Class<?>[] groups() default {};
        public Class<? extends Payload>[] payload() default {};
    }

    @Component
    public class CreateMediaRequestValidator implements ConstraintValidator<CreateMediaRequestValidation, CreateMediaRequestResource> {
        @Override
        public boolean isValid(CreateMediaRequestResource value, ConstraintValidatorContext context) {
            System.out.println(value);
            System.out.println(context);

            return false;
        }}
}

The controller's method:

// ...
public ResponseEntity<MediaMetadataResource> createMedia(
    @RequestBody @ModelAttribute
    @Valid @CreateMediaRequestValidation
    CreateMediaRequestResource data
) {
// this won't fail (and the validator won't print)

// ...
public ResponseEntity<MediaMetadataResource> createMedia(
    @RequestBody @ModelAttribute
    @Valid @CreateMediaRequestValidation
    CreateMediaRequestResource data
) {
// this won't fail (and the validator won't print)

I've shortened the code as much as possible to stay in the chars limit, please ask me anything which might be related. Thank you very much!

7 Replies

JavaBot•2y ago

⌛ This post has been reserved for your question.

Hey @elegos! Please use /close or the Close Post button above when you're finished. Please remember to follow the help guidelines. This post will be automatically closed after 300 minutes of inactivity.

TIP: Narrow down your issue to simple and precise questions to maximize the chance that others will reply in here.

elegosOP•2y ago

I've created a poc for this issue, if you might help: https://drive.google.com/file/d/1C1klw96HCU4UbrCsjRAq4jsgI60lX4E4/view?usp=sharing

Google Docs

spring-poc.zip

elegosOP•2y ago

(swagger interface on http://localhost:54321/swagger-ui/index.html to test it out)

JavaBot•2y ago

💤 Post marked as dormant

This post has been inactive for over 300 minutes, thus, it has been archived. If your question was not answered yet, feel free to re-open this post or create a new one.

elegosOP•2y ago

Still unanswered. Can you help me please? In few words: is it possible to create a validator for the whole model, instead of the single attributes? Thank you 🙂

JavaBot•2y ago

If you are finished with your post, please close it. If you are not, please ignore this message. Note that you will not be able to send further messages here after this post have been closed but you will be able to create new posts.

JavaBot•2y ago

Post Closed

This post has been closed by <@366713959396409346>.

Gaming

Programming

Spring Boot MVC: validate a multipart/form-data RequestBody