Creating a customized 404/500 error page in Play Framework

Question

How can one create global, custom looks for their 404/505 error pages using Play?

Answer 1

Error handling changed in 2.5.x. You now need an ErrorHandler to handle errors and display custom error pages yourself.

The documentation for 2.5.x says:

Supplying a custom error handler

import play.api.http.HttpErrorHandler
import play.api.mvc._
import play.api.mvc.Results._
import scala.concurrent._
import javax.inject.Singleton;

@Singleton
class ErrorHandler extends HttpErrorHandler {

  def onClientError(request: RequestHeader, statusCode: Int, message: String) = {
    Future.successful(
      Status(statusCode)("A client error occurred: " + message)
    )
  }

  def onServerError(request: RequestHeader, exception: Throwable) = {
    Future.successful(
      InternalServerError("A server error occurred: " + exception.getMessage)
    )
  }
}

You can find the default error pages on Github: https://github.com/playframework/playframework/tree/master/framework/src/play/src/main/scala/views/defaultpages

See https://www.playframework.com/documentation/2.5.x/ScalaErrorHandling for more detail.