public static void ShortestPath(String departure, String arrival, org.jgrapht.Graph<String, FlightInfo> f) throws ParseException {
    DijkstraShortestPath<String, FlightInfo> flightPath = new DijkstraShortestPath<>(f, departure, arrival);

    int noOfFlights = (int) flightPath.getPathLength();
    int totalCost = 0;

    for (int i = 0; i < noOfFlights; i++) {
        int cost = flightPath.getPathEdgeList().get(i).getCost();
        totalCost = totalCost + cost;

        time = flightPath.getPathEdgeList().get(i).calculateFlightDuration();
    }

//Error: only gets the value of the last list
     System.out.println("Total Time of Flight: " + time);

public FlightInfo(String departTime, String arriveTime){
        this.departTime = departTime;
        this.arriveTime = arriveTime;
    }
public String calculateFlightDuration() throws ParseException {
        DateFormat form = new SimpleDateFormat("hh:mm");
        Date a = form.parse(departTime);
        Date b = form.parse(arriveTime);

        hh = (b.getTime() - a.getTime()) / 3600000;
        mm = ((b.getTime() - a.getTime()) % 3600000) / 60000;

        String dur = String.valueOf(hh) + " hours and " + String.valueOf(mm) + " minutes";
        return dur;
    }