Error handling in play framework

Question

I am developing a REST API using play framework. I would like to implement a centralized error handling for all my actions.

What is the best way to achieve this?

Answer 1

An alternative way do this is to use a filter, e.g:

object ExceptionFilter extends EssentialFilter {
  def apply(nextFilter: EssentialAction) = new EssentialAction {
    def apply(requestHeader: RequestHeader) = {
      val next: Iteratee[Array[Byte], Result] = nextFilter(requestHeader)

      // Say your backend throws an ItemNotFound exception.
      next recoverWith {
        case e: ItemNotFound => Iteratee.ignore[Array[Byte]]
          .map(_ => Results.NotFound("Item not in the database!"))
      }
    }
  }
}

Then hook that up in your global settings:

object Global extends WithFilters(CSRFFilter(), ExceptionFilter) with GlobalSettings

This potentially allows you to do something with the request body if needed. I agree in most cases using GlobalSettings.onError is probably the easiest approach.

Answer 2

You should have a look at the GlobalSettings: https://www.playframework.com/documentation/2.3.x/ScalaGlobal

Especially, it allows you to override:

def onError(request: RequestHeader, ex: Throwable)
def onHandlerNotFound(request: RequestHeader)
def onBadRequest(request: RequestHeader, error: String)

onError is probably the one you are looking for, but the others may be useful too :)