Validating a lambda request in Micronaut using ConstraintValidator

Question

I have a handler like this and a custom annotation @ValidRequest:

@Introspected
public class MessageHandler extends MicronautRequestHandler<APIGatewayProxyRequestEvent, APIGatewayProxyResponseEvent> {

  @Override
  public APIGatewayProxyResponseEvent execute(@ValidRequest APIGatewayProxyRequestEvent event) {
    return new APIGatewayProxyResponseEvent()
        .withStatusCode(200)
        .withHeaders(Collections.singletonMap("Content-Type", "application/json"))
        .withBody("OK");
  }

}

The annotation itself looks like this:

@Retention(RUNTIME)
@Constraint(validatedBy = {ValidRequestValidator.class})
public @interface ValidRequest {

  String message() default "Request is not valid";
  Class<?>[] groups() default {};
  Class<? extends Payload>[] payload() default {};

}

And the validator is like this:

@Introspected
public class ValidRequestValidator implements ConstraintValidator<ValidRequest, APIGatewayProxyRequestEvent> {

  @Override
  public boolean isValid(
      @Nullable APIGatewayProxyRequestEvent event,
      @NonNull AnnotationValue<ValidRequest> annotationMetadata,
      @NonNull ConstraintValidatorContext context
  ) {
    if (event == null || event.getBody() == null || event.getBody().isEmpty()) {
      throw new RuntimeException("Incorrect request event");
    }
    return true;
  }

}

The problem is that validation is completely ignored. I can send any events with or without body and everything works without exception. I did everything according to the Micronout documentation, what could be wrong?

https://docs.micronaut.io/latest/guide/index.html#beanValidation

Answer 1

Please remove the @Introspect from your validator and try to follow the same as I have done below.

@POST
@Consumes({MediaType.APPLICATION_JSON})
@Produces(MediaType.APPLICATION_JSON)
@Path("/somePath")
public Response workingWithSubscription( @Valid UpdateSubscription updateSubscription) {

---

@ValidUpdateSubscription
public class UpdateSubscription implements UpdateSubscriptionRequest {

}

---

@Target({TYPE})
@Retention(RUNTIME)
@Constraint(validatedBy = UpdateSubscriptionValidator.class)
@Documented
public @interface ValidUpdateSubscription {

    int ERROR_CODE = 1111;

    String message() default "Null value";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};

    int errorCode() default ERROR_CODE;

    Response.Status status() default Response.Status.BAD_REQUEST;
}

---

@Named
@ApplicationScoped
public class UpdateSubscriptionValidator implements ConstraintValidator<ValidUpdateSubscription, UpdateSubscription> {

    @Override
    public boolean isValid(UpdateSubscription value, ConstraintValidatorContext context) {

        return true/OR/false;
    }
}