DateHelper.java

/*
 * Copyright 2013 Simon Thiel
 * 
 * This file is part of SitJar.
 * 
 * SitJar is free software: you can redistribute it and/or modify
 * it under the terms of the GNU LESSER GENERAL PUBLIC LICENSE as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *  
 * SitJar is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with SitJar. If not, see <http://www.gnu.org/licenses/lgpl.txt>. * 
 */
package sit.tools;

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

/**
 *
 * @author simon
 */
public class DateHelper {

    private static final SimpleDateFormat SIMPLE_DATE_FORMAT_SHORT = new SimpleDateFormat("dd.MM.yyyy");
    private static final SimpleDateFormat SIMPLE_DATE_FORMAT_LONG = new SimpleDateFormat("dd.MM.yyyy HH:mm:ss");


    /**
     * increments date by days
     *
     * @param date initial date to be changed
     * @param days +/- days to be added/removed - days will be removed when days
     * is negative
     * @return updated date
     */
    public static Date addDays(Date date, int days) {
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        cal.add(Calendar.DATE, days);
        return cal.getTime();
    }

    public static Date setTimeForDate(Date date, int h, int m, int s) {
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        cal.set(Calendar.HOUR_OF_DAY, h);
        cal.set(Calendar.MINUTE, m);
        cal.set(Calendar.SECOND, s);

        return cal.getTime();
    }


    public static Date setTimeForDate(Date date, Date time) {
        Calendar cal = Calendar.getInstance();
        cal.setTime(time);
        return setTimeForDate(date, cal.get(Calendar.HOUR_OF_DAY),
                cal.get(Calendar.MINUTE), cal.get(Calendar.SECOND));

    }

    public static boolean dateAreOnSameDay(Date d1, Date d2) {
        Calendar cal1 = Calendar.getInstance();
        Calendar cal2 = Calendar.getInstance();
        cal1.setTime(d1);
        cal2.setTime(d2);

        return (cal1.get(Calendar.YEAR) == cal2.get(Calendar.YEAR))
                && (cal1.get(Calendar.DAY_OF_YEAR) == cal2.get(Calendar.DAY_OF_YEAR));
    }


    public static String getShortDate(Date date){
        return (SIMPLE_DATE_FORMAT_SHORT).format(date);
    }

    public static String getLongDate(Date date){
        return (SIMPLE_DATE_FORMAT_LONG).format(date);
    }


}