Play Framework 2.6 Request Handler to ignore trailing slash

IgnoreTrailingSlashesRequestHandler.java

import com.google.inject.Inject;
import org.apache.commons.lang3.StringUtils;
import play.api.mvc.Handler;
import play.api.mvc.Handler$;
import play.api.mvc.RequestHeader;
import play.core.j.JavaHandler;
import play.core.j.JavaHandlerComponents;
import play.http.HandlerForRequest;
import play.http.HttpRequestHandler;
import play.libs.streams.Accumulator;
import play.mvc.EssentialAction;
import play.mvc.Http;
import play.mvc.Results;
import play.routing.Router;
import java.util.Optional;

public class IgnoreTrailingSlashesRequestHandler implements HttpRequestHandler {

    private final Router router;
    private final JavaHandlerComponents handlerComponents;

    @Inject
    public IgnoreTrailingSlashesRequestHandler(Router router, JavaHandlerComponents components) {
        this.router = router;
        this.handlerComponents = components;
    }

    @Override
    public HandlerForRequest handlerForRequest(Http.RequestHeader request) {

        Http.RequestHeader normalizedRequest = this.normalize(request);

        Handler handler = this.getHandlerForRequest(normalizedRequest)
                .orElse(EssentialAction.of(req -> Accumulator.done(Results.notFound())));

        if (handler instanceof JavaHandler) {
            handler = ((JavaHandler) handler).withComponents(handlerComponents);
        }

        return new HandlerForRequest(normalizedRequest, handler);
    }

    private Http.RequestHeader normalize(Http.RequestHeader request) {
        String newPath = this.cleanPath(request.path());
        RequestHeader scalaRequest = request.asScala();
        return scalaRequest.withTarget(scalaRequest.target().withPath(newPath)).asJava();
    }

    private String cleanPath(String origPath) {
        // https://commons.apache.org/proper/commons-lang
        // org.apache.commons : commons-lang3 : 3.7
        return StringUtils.stripEnd(origPath, "/");
    }

    // Get Play Framework request handler
    private Optional<Handler> getHandlerForRequest(Http.RequestHeader request) {
        return router
                .route(request)
                .map(handler ->
                        Handler$.MODULE$
                                .applyStages(request.asScala(), handler)
                                ._2()
                );
    }
}

Note: entries in routes must have no trailing slash in order to be matched, e.g.

Correct:
GET /values @controllers.ValuesController.list

Wrong:
GET /values/ @controllers.ValuesController.list