手动设置日期和时间-java

Question

 public static List<Reservation> addReservations(List<Reservation> reservations, List<Customer> customers) {
    int newReservationId = Reservation.getNumberOfReservations() + 1;
    String startString = readString("Enter Reservation date");
    SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
    Date date = null;
    try {
        date = sdf.parse(startString);
    } catch (ParseException ex) {
        Logger.getLogger(ProjectIncrement5.class.getName()).log(Level.SEVERE, null, ex);
    }
    Calendar dateTime = Calendar.getInstance();
    dateTime.setTime(date);

    listCustomers(customers, reservations);
    int reservationCustomerId = readInt("Enter Customer Id", Customer.getNumberOfCustomers(), 1);
    Customer reservationCustomer = customers.get(reservationCustomerId - 1);
    Reservation res = new Reservation(newReservationId, dateTime, reservationCustomer);
    reservations.add(res);
    return reservations;
}

预订类别：

public class Reservation {

private int reservationId;
private Calendar dateTime;
private Customer customer;


private static int numberOfReservations = 0;

public Reservation() {
    this.reservationId = 0;
    this.dateTime = null;
     this.customer = null;


    numberOfReservations++;
}

public Reservation(int reservationId, Calendar dateTime, Customer customer) {
    this.reservationId = reservationId;
    this.dateTime = dateTime;
      this.customer = customer;

    numberOfReservations++;
}

public static int getNumberOfReservations() {
    return numberOfReservations;
}

public int getReservationId() {
    return reservationId;
}

public void setreservationId(int reservationId) {
    this.reservationId = reservationId;
}

public Calendar getDateTime() {
    return dateTime;
}

    public Customer getCustomer()
{
    return customer;
}

public void setCustomer(Customer customer)
{
    this.customer = customer;
}     



public String setDateTime() {
    SimpleDateFormat formatter = new SimpleDateFormat("dd/MM/yyyy");
    String dateString = formatter.format(this.dateTime.getTime());
    return dateString;
}

@Override
public String toString() {
    return "Reservation id: " + getReservationId() + ", "
            + "Date/Time " + setDateTime() +
    "customer: " + getCustomer();

}
}

这是保存到导致错误的文本文件中的内容：

1:java.util.GregorianCalendar[time=851385600000,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.zoneInfo[id=“欧洲/伦敦”,offset=0,dstSavings=3600000,usedayLight=true,transitions=242,lastrule=java.util.SimpleTimeZone[id=europe/London,offset=0,dstSavings=3600000,usedayLight=true DE=2,endmode=2,endmonth=9,endday=-1,enddayofweek=1,endtime=3600000,endtimemode=2]],firstdayofweek=2,最小daysinfirstweek=4,era=1,year=1996,month=11,week_ofyear=52,week_ofmonth=4,day_off_year=3,day_off_week_in_month=4,am_pm=0,hour=0,hour_off_day=0,minute=0,second=0,millisecond=0,

我认为错误发生在获取日历的实例时，但我不确定如何更容易地做到这一点，并修复这个问题。有人能帮忙吗？

Answer 1

问题是您将calendar.tostring()而不是实际日期存储到文本文件中。

看看你都发了些什么：

第一天Ofweek=2,最小天FirstWeek=4,ERA=1,年=1996,月=11,周=52,周=4,周=24,周=359,周=3,周=4,AM_PM=0,小时=0,周=0,分钟=0,秒=0,毫秒=0,Zone_offset=0,Dst_offset=0

那似乎是个正确的日期。我会说更多，这似乎是一个真正完整的约会，有很多信息不是吗？？？；）

我不知道这个日期应该如何存储，但是，例如，如果您想以dd/mm/yyyy的格式存储日期，请使用这几行代码检查它是否是有效的日期（您已经在代码中这样做了）。

SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy");
date = sdf.parse(startString);

检查后，如果startstring有效，则不需要创建任何calendar实例，只需将startstring写入文本文件。

没有。这个想法是：

• 在Java类中，存储在特定的对象中(日历可以，但日期也可以）
• 在文本文件中，通过字符串发送人类可读的日期。

很抱歉，我不能说得更具体，我无法执行您的代码，因为缺少许多部分(customer、readint、listcustomers等）。