java - Date类问题:Date对象被设置为我未设置的对象

我正在尝试为TrainTimeTable添加延迟。我已经使用Date对象使火车到达和离开。当我第一次打印时间表时，一切都显示正确的到达和离开时间。
但是，在所有车站埃德蒙顿及之后增加30分钟的延迟之后。
一些到达和离开时间变得不正确。
延误只能推迟到达和离开的时间，但会改变某些城市之间的旅行时间。

我已经像这样使我的getter和setter方法：

/**
 * Accessor for arrival Date variable. Returns a copy of the arrival date.
 * @return - a copy of the arrival date
 */
public Date getArrivalDate()
{
    //return a copy of the original date
    return (Date) arrival.clone();
}


/**
 * Mutator for arrival date variable.
 * @param arrival - the date to set
 */
public void setArrivalDate( Date arrival )
{
    //uses copy of Date passed in
    this.arrival = (Date) arrival.clone();
}

这是我添加延迟的方法
我使用LinkedList个Station对象来保存时间表：

public void delay(String Station, int minute) {
    //sequential search for Station
    //iterate through list for Station
    boolean delayPoint = false;

    //1 ) adjust time of day
    //add delay to arrival and departure date objects
    for (Station current : schedule) {
        //By checking for delay before checking for the delay city
        //we will see the delayPoint variable set while on
        //the loop is at the station right afer the delayed Station
        //if after the delay point
        if (delayPoint) {
            //then add delay to arrive date
            Date arrivalDate = current.getArrivalDate();
            long arrivalTime = current.getArrivalDate().getTime();
            arrivalTime += minute * MIN_TO_MS;
            arrivalDate.setTime(arrivalTime);
            current.setArrivalDate(arrivalDate);
            //and add delay to depart date
            Date departDate = current.getDepartureDate();
            long departTime = current.getDepartureDate().getTime();
            departTime += minute * MIN_TO_MS;
            departDate.setTime(departTime);
            current.setDepartureDate(departDate);

        } //if the Station matches the point of delay
        else if (current.getCity().equals(Station)) {
            //then set the boolean
            delayPoint = true;
            //and add delay to departure
            Date departDate = current.getDepartureDate();
            long departTime = current.getDepartureDate().getTime();
            departTime += minute * MIN_TO_MS;
            departDate.setTime(departTime);
            current.setDepartureDate(departDate);
        }

    }
    //2 ) adjust day of trip
}

Here is my output after adding a delay of 30 min to Edmonton departure

谢谢，麻烦您了，
阿森·侯赛因。

最佳答案

这是一种可能的解决方案（基于java 8和java.time api）

车站等级

    public class Station {
        private long id;
        private String name;
        private Date arrivalDate;
        private Date departureDate; ....getters and setters

阵列电台列表

    List<Station> myStations = Arrays.asList(
            new Station(1,"City1",new Date(),new Date()),
            new Station(2,"City2",new Date(),new Date()),
            new Station(3,"City3",new Date(),new Date()),
            new Station(4,"City4",new Date(),new Date())
    );

查找和延迟时间的城市名称（以分钟为单位）。

String cityName = "City2";
int minutes = 30;

获取与CityName相等的Station（此刻，我正在显示一种替代方法来表示foor循环）

    Station current = myStations.stream()
            .filter(s -> s.getName().equals(cityName))
            .findFirst().orElse(null);

当前电台等于城市名称，因此可以增加延迟

delay(current,minutes,false);

现在为下一个电台添加延迟（假设下一个电台的ID比当前电台更强）

myStations.stream()
                .filter(s -> s.getId()>current.getId())
                .collect(Collectors.toList())
                .forEach(s -> delay(s,minutes,true));

delay方法（此延迟方法基于java.time api）

public static void delay(Station current, int minutes, boolean isDelay){
    System.out.println("Current Station | Before: " + current);
    LocalDateTime stationArrival =null;
    LocalDateTime stationDeparture=null;


    if (current !=null && isDelay){
        stationArrival = getLocalDateTimeFromDate(current.getArrivalDate());
        stationDeparture = getLocalDateTimeFromDate(current.getDepartureDate());
        stationArrival=stationArrival.plusMinutes(minutes);
        stationDeparture=stationDeparture.plusMinutes(minutes);
        current.setArrivalDate(getDateFromLocalDateTime(stationArrival));
        current.setDepartureDate(getDateFromLocalDateTime(stationDeparture));
    }else if(current!=null && !isDelay){
        stationDeparture = getLocalDateTimeFromDate(current.getDepartureDate());
        stationDeparture= stationDeparture.plusMinutes(minutes);
        current.setDepartureDate(getDateFromLocalDateTime(stationDeparture));
    }

    System.out.println("Current Station | After: " + current);
}

helppers方法从Date LocaleDateTime转换

public static  LocalDateTime getLocalDateTimeFromDate(Date date){
    return LocalDateTime.ofInstant(date.toInstant(), ZoneId.systemDefault());
}

public static Date getDateFromLocalDateTime(LocalDateTime localDateTime){
    return Date.from(localDateTime.atZone(ZoneId.systemDefault()).toInstant());
}

这种选择基于使用LocalDateTime的java.time api，java.time非常适合我。使用java.uitl.Date可以完成许多转换，很难处理。如果您有兴趣了解有关java.time的更多信息，请参见教程Java Date Time Api.

希望能帮助到你。

关于java - Date类问题:Date对象被设置为我未设置的对象，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/45395015/