Shutdown play framework gracefully

GracefulShutdownPlay.scala

// from https://github.com/playframework/playframework/issues/1789
import scala.concurrent.duration.Duration;
import scala.concurrent.duration.FiniteDuration;

import play.api.Application;
import play.api.Play;

import akka.actor.ActorSystem;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import sun.misc.Signal;

import java.util.concurrent.TimeUnit;
import javax.inject.Inject;
import javax.inject.Provider;
import javax.inject.Singleton;

@Singleton
public class SignalHandler {

  private static final Logger LOG = LoggerFactory.getLogger(SignalHandler.class);

  private static final FiniteDuration STOP_DELAY = Duration.create(40, TimeUnit.SECONDS);

  private volatile boolean isShuttingDown = false;

  @Inject
  SignalHandler(ActorSystem actorSystem, Provider<Application> applicationProvider) {
    Signal.handle(new Signal("TERM"), new sun.misc.SignalHandler() {
      @Override
      public void handle(Signal signal) {
        isShuttingDown = true;
        LOG.info("Termination required, swallowing SIGTERM to allow current requests to finish");
        actorSystem.scheduler().scheduleOnce(STOP_DELAY, () -> {
          Play.stop(applicationProvider.get());
        }, actorSystem.dispatcher());
      }
    });
  }

  public boolean isShuttingDown() {
    return isShuttingDown;
  }

}