POST param validation in Akka HTTP - akka-http

Question

Is it possible to validate the POST body in Akka Http?
Case Class Validationseems to work only for get requests.
As an example:
case class User(name: String){
require(name)
}
.....
(post & entity(as[User])) { user =>
complete(doSomething(user.name))
}
I would like the above code to throw a ValidationRejection rejection

Answer 1

You can use require inside scope of complete directive
(path("stats") & parameter("idsParam")) { idsParam =>
complete {
require(idsParam.length > 1)
val ids = idsParam.split(",").map(v => CaseId(v).value)
DBManager.getArticleStats(ids).map { case (id, stats) => IdWithValue(CaseId(id), stats) }
}
}
that handles yours POST request.
And typically I have custom exception handler that wraps all exceptions into format that my API client expects such as json. require throws IllegalArgumentException so let's handle it in special way if we want to.
protected implicit def myExceptionHandler =
ExceptionHandler {
case ex: IllegalArgumentException => ctx => {
val cause = ex.getCause
ex.printStackTrace()
ctx.complete(StatusCodes.InternalServerError, ErrorResponse(ex.code, ex))
}
case ex: Throwable => ctx =>
logger.warning("Request {} could not be handled normally", ctx.request)
ex.printStackTrace()
ctx.complete(StatusCodes.InternalServerError, ErrorResponse(StatusCodes.InternalServerError.intValue, ex))
}
where ErrorResponse is my case class that is being serialized to json using spray-json