#ControllerAdvice handle the exception but not customize response - spring

Question

This is my exception handler
#ControllerAdvice(basePackageClasses = [SignUpController::class])
class ControllerAdvice: ResponseEntityExceptionHandler() {
#ExceptionHandler(Exception::class)
#ResponseBody
fun handleControllerException(request: HttpServletRequest, ex: Throwable): ResponseEntity<*> {
val status = HttpStatus.CONFLICT
return ResponseEntity<Any>(ApiError(status.value(), ex.message), status)
}
}
and my custom class
data class ApiError(val status: Int, val message: String?)
The handler work but error is throw like follow
{
"timestamp": "2019-01-29T19:17:22.541+0000",
"status": 401,
"error": "Unauthorized",
"message": "could not execute statement; SQL [n/a]; constraint [null]; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement",
"path": "/sign-up"
}
But I'm expected for something like follow
{
"apierror": {
"status": ...,
"message": ..."
}
}
I'm based for this tutorials
https://www.toptal.com/java/spring-boot-rest-api-error-handling
https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#boot-features-error-handling
https://medium.com/#jovannypcg/understanding-springs-controlleradvice-cd96a364033f
What I'm doing wrong? I'm missing any config?

Answer 1

You need to annotate your ApiError class with the following:
#Data
#JsonTypeInfo(
include = JsonTypeInfo.As.WRAPPER_OBJECT,
use = JsonTypeInfo.Id.CUSTOM,
property = "error",
visible = true
)
#JsonTypeIdResolver(LowerCaseClassNameResolver.class)

Answer 2

My workaround was, but is not the correct answer
on application.yaml
server:
error:
include-exception: true
on my controller I'm check if email and username exists and throw a custome message to exception
#RestController
#RequestMapping("/register")
class RegisterController: BaseController() {
#ResponseStatus(HttpStatus.CREATED)
#PostMapping("/save")
fun register(#RequestBody user: ApplicationUser) {
if (userRepository.existsByEmail(user.email)) {
throw DataIntegrityViolationException("Email already exists")
}
if (userRepository.existsByUsername(user.username)) {
throw DataIntegrityViolationException("Username already exists")
}
user.password = bCryptPasswordEncoder.encode(user.password)
userRepository.save(user)
}
}
and the return worked fine
{
"timestamp": "2019-01-31T17:08:40.832+0000",
"status": 500,
"error": "Internal Server Error",
"exception": "org.springframework.dao.DataIntegrityViolationException",
"message": "Email already exists", //here is
"path": "/register/save"
}