Question

我正在开发一个程序，它将是一个基本功能，如果用户可以检查一些东西，程序将计算一个截止日期，为了简单起见，将在七天后。此函数在其他类中使用，现在已在使用它的类中定义

today=Calendar.getInstance();

我正在使用Calendar类来执行此操作。起初我试过这个

  public Calendar getReturnDate()
  {
   Calendar dueDate = Calendar.getInstance();
   dueDate.set(today.MONTH, today.get(today.MONTH));
   dueDate.set(today.YEAR, today.get(today.YEAR));
   dueDate.add(today.DATE,today.get(today.DATE + 7));

   return dueDate;
}

这给了我一个结果，一切都打印到毫秒。

所以我研究了Calendar类，发现.add方法可以完成这个工作......或者我认为。以下是代码

    public Calendar getReturnDate()
{
   Calendar dueDate = Calendar.getInstance();
   dueDate.set(today.MONTH, today.get(today.MONTH));
   dueDate.set(today.YEAR, today.get(today.YEAR));
   dueDate.add(today.DATE,7);

   return dueDate;
}

在以下代码中调用该函数时，将发生以下打印。

    public String toString()
 {
     //Prints them out
     String str = "The specs of the book are: ";
     str+= "\n\t Title: " + title;
     str+= "\n\t Author: " + year;
     str += "\n\t checkout date: " + (getReturnDate().MONTH+1) + "/" + getReturnDate().DATE;
     return str;
 }

结果：

 Title: ABC
 Author: Suzie Smith
 checkout date: java.util.GregorianCalendar[time=1428600973310,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id="America/New_York",offset=-18000000,dstSavings=3600000,useDaylight=true,transitions=235,lastRule=java.util.SimpleTimeZone[id=America/New_York,offset=-18000000,dstSavings=3600000,useDaylight=true,startYear=0,startMode=3,startMonth=2,startDay=8,startDayOfWeek=1,startTime=7200000,startTimeMode=0,endMode=3,endMonth=10,endDay=1,endDayOfWeek=1,endTime=7200000,endTimeMode=0]],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2015,MONTH=3,WEEK_OF_YEAR=15,WEEK_OF_MONTH=2,DAY_OF_MONTH=9,DAY_OF_YEAR=99,DAY_OF_WEEK=5,DAY_OF_WEEK_IN_MONTH=2,AM_PM=1,HOUR=1,HOUR_OF_DAY=13,MINUTE=36,SECOND=13,MILLISECOND=310,ZONE_OFFSET=-18000000,DST_OFFSET=3600000]

正如您所看到的，这是无法正常运行的。我想在上面的代码中调用此方法时打印出月/年。

有人知道怎么做或为什么我的工作不起作用？

来源： https://docs.oracle.com/javase/7/docs/api/java/util/GregorianCalendar.html

Answer 1

public String toString() {
    Calendar returnDate = getReturnDate();
    // Prints them out
    String str = "The specs of the book are: ";
    str += "\n\t Title: " + title;
    str += "\n\t Author: " + year;
    str += "\n\t checkout date: " + (returnDate.get(Calendar.MONTH) + 1) + "/" + returnDate.get(Calendar.DATE);
    return str;
}

日历类＆＃34;正常＆＃34;发行日期

1 个答案: