import java.math.BigDecimal;
import java.math.BigInteger;
import java.text.ParseException;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* 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 {
//-----------------------------------------------------------------------
/**
* Adds a number of months to a date returning a new object.
* The original date object is unchanged.
*
* @param date the date, not null
* @param amount the amount to add, may be negative
* @return the new date object with the amount added
* @throws IllegalArgumentException if the date is null
*/
public static Date addMonths(Date date, int amount) {
return add(date, Calendar.MONTH, amount);
}
//-----------------------------------------------------------------------
/**
* Adds to a date returning a new object.
* The original date object is unchanged.
*
* @param date the date, not null
* @param calendarField the calendar field to add to
* @param amount the amount to add, may be negative
* @return the new date object with the amount added
* @throws IllegalArgumentException if the date is null
*/
private static Date add(Date date, int calendarField, int amount) {
if (date == null) {
throw new IllegalArgumentException("The date must not be null");
}
Calendar c = Calendar.getInstance();
c.setTime(date);
c.add(calendarField, amount);
return c.getTime();
}
}