error.scala

import scala.concurrent.Future
import scala.util.{Failure, Success, Try}
import scala.concurrent.ExecutionContext.Implicits.global

def fail = throw new RuntimeException("error now")

def failInFuture() = Future { throw new RuntimeException("error in future") }

try {
  fail
} catch {
  case e: Exception => println(e.getMessage)
}

failInFuture().onComplete {
  case Success(result) =>
  case Failure(t) => println("error reported in onComplete")
}

failInFuture().onFailure {
  case e => println("error reported in onFailure")
}

failInFuture().recover {
  case e => println("error reported in recover")
}


Try (fail).failed.map(e => println(e.getMessage))
failInFuture().failed.map(e => println(e.getMessage))