ova2

class LongRunningTaskService {
    public <T> CompletableFuture<T> executeCompletableFuture(Supplier<T> task) {
        CompletableFuture<T> completableFuture = new CompletableFuture<>();

        new Thread(() -> {
            try {
                System.out.println("Do something before task execution ...");
                completableFuture.complete(task.get());
                System.out.println("Do something after task execution ...");
            } catch (Exception exception) {

ova2

  Future<void> _requestTrackPositions(
      String correlationId, String deviceId, String station, String trackNumber) async {
    _messagingService.request(
        topicRetrieveTrackPositionsQuery,
        jsonEncode(RetrieveTrackPositionsQuery(
            mobileDeviceId: deviceId,
            correlationId: correlationId,
            station: station,
            trackNumber: trackNumber)));
  }

ova2

final RequestReplyService requestReplyService = RequestReplyService();

// request track positions and wait for received response
final TrackPositionsRetrievedResponse response = await requestReplyService.execute(
  request: () => _requestTrackPositions(correlationId, mobileDeviceId, station, trackNumber),
  response: () => _trackPositionRetrieved$(correlationId, mobileDeviceId));

// do something with response ...

ova2

import 'package:mqtt_client/mqtt_client.dart';
import 'package:rxdart/rxdart.dart';

class MessagingService {  
  /// Subscribes to the given topic and produces a stream of received updates from the message
  /// broker matching this topic. You can also pass [MqttQos] which defaults to atLeastOnce.
  ///
  /// This method returns a stream of [MqttMessage] instances.
  Stream<MqttMessage> updatesFor(String topic, [MqttQos qos = MqttQos.atLeastOnce]) {
    ...

ova2

import 'dart:async';

import 'package:flutter/foundation.dart';

/// This class allows request-reply communication over messaging.
class RequestReplyService {
  StreamSubscription _subscription;

  /// release resources
  void dispose() {

ova2

@Component({
  selector: 'app-identify-device',
  template: `
    ...
    <form (submit)="identifyDevice()" [formGroup]="formGroup">
      <ion-item>
        <ion-label color="dark" [position]="'stacked'">Track Number</ion-label>
        <ion-input clearInput type="text" formControlName="trackNumber"></ion-input>
      </ion-item>
    </form>

ova2

@Injectable({
  providedIn: 'root'
})
export class LoggedInGuard implements CanActivate {

  protected constructor(private _router: Router, _store: CoreStore) { }

  public canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Promise<boolean> {
    return this._store.ready$.then(() => this.toResult(), () => this.toResult());
  }

ova2

@Injectable({
  providedIn: 'root'
})
export class CoreFacade {

  public isLoggedIn$ = this._store.select((state: CoreState) => !!state.authToken);
  
  constructor(private _store: CoreStore, private _loginService: LoginService) { }

  public getTrackNumber(): string {

ova2

import { Injectable } from '@angular/core';
import { Storage } from '@ionic/storage';

@Injectable({
  providedIn: 'root'
})
export class StoreService {

  private readonly _prefix: string;
  private readonly AUTH_TOKEN = 'authToken';

ova2

import { BehaviorSubject, Observable } from 'rxjs';
import { distinctUntilChanged, map } from 'rxjs/operators';

export abstract class Store<T> {

  private _state$: BehaviorSubject<T>;

  protected constructor(initialState: T) {
    this._state$ = new BehaviorSubject(initialState);
  }