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 { //----------------------------------------------------------------------- /** * Sets the seconds field to a date returning a new object. * The original date object is unchanged. * * @param date the date, not null * @param amount the amount to set * @return a new Date object set with the specified value * @throws IllegalArgumentException if the date is null * @since 2.4 */ public static Date setSeconds(Date date, int amount) { return set(date, Calendar.SECOND, amount); } //----------------------------------------------------------------------- /** * Sets the specified field to a date returning a new object. * This does not use a lenient calendar. * The original date object is unchanged. * * @param date the date, not null * @param calendarField the calendar field to set the amount to * @param amount the amount to set * @return a new Date object set with the specified value * @throws IllegalArgumentException if the date is null * @since 2.4 */ private static Date set(Date date, int calendarField, int amount) { if (date == null) { throw new IllegalArgumentException("The date must not be null"); } // getInstance() returns a new object, so this method is thread safe. Calendar c = Calendar.getInstance(); c.setLenient(false); c.setTime(date); c.set(calendarField, amount); return c.getTime(); } }