Spring webflux bean validation not working

Question

I am trying to use bean validation in Webflux. This is what I have so far:

@PostMapping(\"contact\")
fun create(@RequestBody @Valid contact: Mono)         


        

Answer 1

I had to combine few of the answers from SO to get the validation correct. What I did was:

• Made my data class as suggested here.

  • Then i used javax.validation.Validator class to validate the data class.

import javax.validation.Validator import javax.validation.ConstraintViolationException

@Service
open class MyService {
    @Autowired
    lateinit var repository: UserRepository

    @Autowired
    lateinit var validator: Validator

     open fun createUser(user: User): Mono {
         val violations = validator.validate(user)
          //if it violates our constraints, it will throw an exception, which we 
          //handle using global exception handler
          if(violations.isNotEmpty()){
               throw ConstraintViolationException(violations)
           }
           return repo.save(user)
         }
. . .
}

• Add these lines in application.properties.

spring.mvc.throw-exception-if-no-handler-found=true
spring.resources.add-mappings=false

And to catch the exceptions.

@RestControllerAdvice    
open class ExceptionHandlers {

  @ExceptionHandler(ConstraintViolationException::class)
  @ResponseStatus(HttpStatus.BAD_REQUEST)
  fun throwConstraintViolationExcetion(ex: ConstraintViolationException): ApiResponse {
    return ApiResponse (message= ex.message.toString(), data= null);
  }
}

p.s ApiResponse is just a data class that takes server message & data as parameters. No need to handle errors in @Controller as it will be thrown by the @Service class