Question

行程类通过以下成员存储有关行程的信息：

•一个名为flight的私有ArrayList数据字段，其中包含该行程的航班出发时间的递增顺序。 （提示：您无需进行排序。）

•一个构造函数，它使用ArrayList类型的指定航班创建行程。

•一种名为getTotalFlightTime（）的方法，该方法以分钟为单位返回行程的总飞行时间。 （提示：为每个Flight对象调用getFlightTime（）方法。）

•一种名为getTotalTravelTime（）的方法，该方法以分钟为单位返回从行程中首个航班的出发时间至最后一个航班的到达时间。假设所有时间在同一时区。

package que6;

/**
 *
 * @author vpi764
 */


import java.util.ArrayList;
import java.util.GregorianCalendar;
public class TestFlightItinerary {


    public static void main(String[] args) {

  lic static void main(String[] args) {
        ArrayList<Flight>flights = new ArrayList<>();
  Flight F1 =  new Flight("US230", new GregorianCalendar(2014, 5, 5, 5, 5, 0), new GregorianCalendar(2014, 5, 5, 6, 15, 0));
    Flight F2 =  new Flight("US235", new GregorianCalendar(2014, 5, 5, 6, 55, 0), new GregorianCalendar(2014, 5, 5, 7, 45, 0));
      Flight F3 =  new Flight("US237", new GregorianCalendar(2014, 5, 5, 9, 35, 0), new GregorianCalendar(2014, 5, 5, 12, 55, 0));

      flights.add(F1);
      flights.add(F2);
      flights.add(F3);

 }

}

class Flight{

        private String flightNo;
        private GregorianCalendar departureTime;
        private GregorianCalendar arrivalTime;


        //Constructor
        Flight(String SpecNo,GregorianCalendar SpecDtime ,GregorianCalendar SpecAtime ){
            this.flightNo = SpecNo;
            this.departureTime = SpecDtime;
            this.arrivalTime = SpecAtime;
        }
        //Getters
        public String GetFlightNo() {
            return flightNo;
        }
        public GregorianCalendar GetDtime() {
            return departureTime;
        }
        public GregorianCalendar GetAtime() {
            return arrivalTime;
        }

        //setters
        // If we don't use setter the could would still work because we are getting input in constructor with parameters
        public void SetFlightNo(String Number) {
            flightNo = Number;
        }
        public void SetDtime(GregorianCalendar Dtime) {
            departureTime = Dtime;
        }
        public void SetAtime(GregorianCalendar Atime) {
            arrivalTime = Atime;
        }

        public long getTimeinMillis() {
                return (arrivalTime.getTimeInMillis() - departureTime.getTimeInMillis());
                }
                // getFlightTime method
                public long getFlightTime() {
                return getTimeinMillis() / (60 * 1000);
                }
    }

class Itinerary {


    ArrayList<Flight> flights = new ArrayList<>();

   public Itinerary(){
           this.flights = flights;
    }
    public long getTotalFlightTime(ArrayList<Flight> flights){

    }
    public long getTotalTravelTime(){

    }


}

Answer 1

ArrayList保持添加元素的顺序。可能就是这样。

Answer 2

如果我正确理解了说明，则无需对ArrayList进行排序。您所需要做的就是定义一个接受一个FlightArray的构造函数。

您的行程表应该是：

class Itinerary {
    ArrayList<Flight> flights; // no need to instantiate, flights passed in as arg

    public Itinerary(ArrayList<Flight> flights) {
        this.flights = flights;
    }

    public long getTotalFlightTime(){
        // Do stuff
    }
    public long getTotalTravelTime(){
        // Do Stuff
    }
}

然后在您的主要方法中添加以下内容：

ArrayList<Flight> flights = new ArrayList<>();
flights.addAll(F1, F2, F3);
Itinerary myItinerary = new Itinerary(flights);

我无法弄清楚getTotalFlightTime（）

2 个答案: