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/*
* Copyright 2008-2012 Sergey Skladchikov
*
* Licensed 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.
*/
package org.gwt.advanced.client.util;
import com.google.gwt.core.client.GWT;
import org.gwt.advanced.client.ui.resources.CalendarConstants;
import java.util.Date;
/**
* This class simplifies operations related to dates.
* It uses {@link org.gwt.advanced.client.ui.resources.CalendarConstants} interface for some calculations.
* You can localize the helper using properties file placed in the folder org/gwt/advanced/client/resources.
*
* @author Sergey Skladchikov
* @since 1.0.0
*/
@SuppressWarnings({"deprecation"})
public class DateHelper {
/**
* number of days per month
*/
private static final int[] DAYS_PER_MONTH = new int[]{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
/**
* weekedn days (Sunday and Saturday)
*/
public static final int[] WEEK_END_DAYS = {0, 6};
/**
* a date to operate with
*/
private Date date;
/**
* the first day of week (usually 0 - Sunday)
*/
private int firstDayOfWeek;
/**
* Creates an instance of this class.
*
* @param date is a date to operate with.
*/
public DateHelper(Date date) {
this.date = date;
this.firstDayOfWeek =
Integer.valueOf(((CalendarConstants) GWT.create(CalendarConstants.class)).firstDayOfWeek());
}
/**
* Creates an instance of this class.
*
* @param year is a year number.
* @param month is a month number (from 0 to 11).
* @param day is a day number.
* @param hours is a hours number (from 0 to 23).
* @param minutes is a minutes number.
* @param seconds is a seconds number.
*/
public DateHelper(int year, int month, int day, int hours, int minutes, int seconds) {
this(new Date(year - 1900, month, day, hours, minutes, seconds));
}
/**
* This method gets a week day number.
* Usually a week starts from Sunday (0), but in some localizations it can start from Monday. In this case
* all numbers will be shifted, i.e. Monday (0), Tuesday (1),..., Sunday (6).
*
* @return a number of week day.
*/
public int getDayOfWeek() {
int day = date.getDay() - firstDayOfWeek;
if (day < 0)
day = 7 + day;
return day;
}
/**
* This method gets a day in the month.
*
* @return a day number.
*/
public int getDay() {
return date.getDate();
}
/**
* This method gets a month in the year starting from 0.
*
* @return a month number.
*/
public int getMonth() {
return date.getMonth();
}
/**
* This method gets the year.
*
* @return the year.
*/
public int getYear() {
return 1900 + date.getYear();
}
/**
* This method gets a hours number from 0 to 23.
*
* @return a hours number.
*/
public int getHours() {
return date.getHours();
}
/**
* This method gets minutes number.
*
* @return a number of minutes.
*/
public int getMinutes() {
return date.getMinutes();
}
/**
* This method gets seconds number.
*
* @return a seconds number.
*/
public int getSeconds() {
return date.getSeconds();
}
/**
* This method gets a number of days in the month.
*
* @return a number of days.
*/
public int getNumberOfDaysInMonth() {
if ((getMonth() == 1) && ((getYear() % 400 == 0) ||
((getYear() % 100 != 0) && (getYear() % 4 == 0))))
return 29;
else
return DAYS_PER_MONTH[getMonth()];
}
/**
* This method cuts time data from the date.
*
* @return the resulting date.
*/
public Date trim() {
return new Date(date.getYear(), date.getMonth(), date.getDate());
}
/**
* This method adds days to the date.
*
* @param days a number of days to add.
* @return the resulting date.
*/
public Date addDays(int days) {
return new Date(date.getYear(), date.getMonth(), date.getDate() + days, date.getHours(), date.getMinutes(), date.getSeconds());
}
/**
* This method adds months to the date.
*
* @param months a number of months to add.
* @return the resulting date.
*/
public Date addMonths(int months) {
return new Date(date.getYear(), date.getMonth() + months, date.getDate(), date.getHours(), date.getMinutes(), date.getSeconds());
}
/**
* This method adds years to the date.
*
* @param years a number of years to add.
* @return the resulting date.
*/
public Date addYears(int years) {
return new Date(date.getYear() + years, date.getMonth(), date.getDate(), date.getHours(), date.getMinutes(), date.getSeconds());
}
/**
* This method gets a week number starting from the first of January (the first week).
*
* @return a week number.
*/
public int getWeekNumber() {
DateHelper dateHelper = new DateHelper(new Date(date.getYear(), 0, 1));
Date firstDay = dateHelper.getFirstDayOfWeek();
int days = getDaysFrom(firstDay);
return days / 7 + 1;
}
/**
* This method returns the first date of the week.
*
* @return the first date of the week.
*/
public Date getFirstDayOfWeek() {
return new Date(date.getYear(), date.getMonth(), date.getDate() - getDayOfWeek());
}
/**
* This method returns the last date of the week.
*
* @return the last date of the week.
*/
public Date getLastDayOfWeek() {
return new Date(date.getYear(), date.getMonth(), date.getDate() + 6 - getDayOfWeek());
}
/**
* This method gets a number of days starting from the specified date.
*
* @param startDate is a start date.
* @return a number of days.
*/
public int getDaysFrom(Date startDate) {
return (int) Math.round((double) (trim().getTime() - new DateHelper(startDate).trim().getTime()) / 86400000);
}
/**
* This method returns the first date of the month.
*
* @return the first date of the month.
*/
public Date getFirstDayOfMonth() {
return new Date(date.getYear(), date.getMonth(), 1);
}
/**
* This method returns the last date of the month.
*
* @return the last date of the month.
*/
public Date getLastDayOfMonth() {
return new Date(date.getYear(), date.getMonth(), new DateHelper(date).getNumberOfDaysInMonth());
}
/**
* This method defines whether the specified week day is a weekend.
*
* @param weekDay is a week day number.
* @return true if the day is weekend.
*/
public static boolean isWeekEndDay(int weekDay) {
for (int holidayWeekDay : WEEK_END_DAYS) {
if (holidayWeekDay == weekDay)
return true;
}
return false;
}
/**
* Checks whether the date is weekend.
*
* @return the result of check.
*/
public boolean isWeekEndDay() {
int day = new DateHelper(date).getDayOfWeek() + firstDayOfWeek;
if (day > 6)
day = day - 7;
return isWeekEndDay(day);
}
/**
* Returns the date.
*
* @return a date value.
*/
public Date getDate() {
return date;
}
}