Kotlin spring boot #RequestBody validation is not triggered - spring

Question

I have a problem on a project with validating #RequestBody by using
implementation("org.springframework.boot:spring-boot-starter-validation")
My DTO looks like this:
import javax.validation.constraints.Email
import javax.validation.constraints.Pattern
class LoginDto(
#Email
val email: String,
#Pattern(regexp = Constants.PASSWORD_REGEX)
val password: String
)
And Controller looks like this:
import org.springframework.validation.annotation.Validated
import org.springframework.web.bind.annotation.PostMapping
import org.springframework.web.bind.annotation.RequestBody
import org.springframework.web.bind.annotation.RestController
import javax.validation.Valid
#RestController
#Validated
class AuthController(private val authService: AuthService) {
#PostMapping("login")
fun login(#Valid #RequestBody loginDto: LoginDto): LoginResponse {
return authService.login(loginDto)
}
...
}
And there is no error from validation, if I try to pass invalid data:
{
"password":"hello",
"email":"dfdfdfdf"
}
I get no error
I use Exposed instead of jpa but I think it's not related to the problem

Answer 1

You should change the annotations of #email and #Pattern to #field:Email and #field:Pattern for example.
The reason for this is twofold, on the one hand you place the annotations on Kotlin properties, and Kotlin properties kan be accessed in a variety of ways. Therefore, you need to specify how you want to access the property to apply the annotation on. On the other hand, the annotations have a set of predefined targets. You can inspect the annotation to see for example that it has a target of field. That's why we can use the #field:Pattern and #field:Email.
This is a key difference with java, where you have have distinct getters, setters, and fields amongst others.