A suite of utilities surrounding the use of the * {@link java.util.Calendar} and {@link java.util.Date} object.
* *DateUtils contains a lot of common methods considering manipulations * of Dates or Calendars. Some methods require some extra explanation. * The truncate and round methods could be considered the Math.floor(), * Math.ceil() or Math.round versions for dates * This way date-fields will be ignored in bottom-up order. * As a complement to these methods we've introduced some fragment-methods. * With these methods the Date-fields will be ignored in top-down order. * Since a date without a year is not a valid date, you have to decide in what * kind of date-field you want your result, for instance milliseconds or days. *
* * * * @author Serge Knystautas * @author Stephen Colebourne * @author Janek Bogucki * @author Gary Gregory * @author Phil Steitz * @author Robert Scholte * @since 2.0 * @version $Id: DateUtils.java 634096 2008-03-06 00:58:11Z niallp $ */ public class Main { //----------------------------------------------------------------------- /** *Checks if two date objects are on the same day ignoring time.
* *28 Mar 2002 13:45 and 28 Mar 2002 06:01 would return true. * 28 Mar 2002 13:45 and 12 Mar 2002 13:45 would return false. *
* * @param date1 the first date, not altered, not null * @param date2 the second date, not altered, not null * @return true if they represent the same day * @throws IllegalArgumentException if either date isnull
* @since 2.1
*/
public static boolean isSameDay(Date date1, Date date2) {
if (date1 == null || date2 == null) {
throw new IllegalArgumentException("The date must not be null");
}
Calendar cal1 = Calendar.getInstance();
cal1.setTime(date1);
Calendar cal2 = Calendar.getInstance();
cal2.setTime(date2);
return isSameDay(cal1, cal2);
}
/**
* Checks if two calendar objects are on the same day ignoring time.
* *28 Mar 2002 13:45 and 28 Mar 2002 06:01 would return true. * 28 Mar 2002 13:45 and 12 Mar 2002 13:45 would return false. *
* * @param cal1 the first calendar, not altered, not null * @param cal2 the second calendar, not altered, not null * @return true if they represent the same day * @throws IllegalArgumentException if either calendar isnull
* @since 2.1
*/
public static boolean isSameDay(Calendar cal1, Calendar cal2) {
if (cal1 == null || cal2 == null) {
throw new IllegalArgumentException("The date must not be null");
}
return (cal1.get(Calendar.ERA) == cal2.get(Calendar.ERA) &&
cal1.get(Calendar.YEAR) == cal2.get(Calendar.YEAR) &&
cal1.get(Calendar.DAY_OF_YEAR) == cal2.get(Calendar.DAY_OF_YEAR));
}
}