datehelper.java

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/*
 * Copyright (c) 2003 Sun Microsystems, Inc.  All rights reserved.  U.S.
 * Government Rights - Commercial software.  Government users are subject
 * to the Sun Microsystems, Inc. standard license agreement and
 * applicable provisions of the FAR and its supplements.  Use is subject
 * to license terms.
 *
 * This distribution may include materials developed by third parties.
 * Sun, Sun Microsystems, the Sun logo, Java and J2EE are trademarks
 * or registered trademarks of Sun Microsystems, Inc. in the U.S. and
 * other countries.
 *
 * Copyright (c) 2003 Sun Microsystems, Inc. Tous droits reserves.
 *
 * Droits du gouvernement americain, utilisateurs gouvernementaux - logiciel
 * commercial. Les utilisateurs gouvernementaux sont soumis au contrat de
 * licence standard de Sun Microsystems, Inc., ainsi qu'aux dispositions
 * en vigueur de la FAR (Federal Acquisition Regulations) et des
 * supplements a celles-ci.  Distribue par des licences qui en
 * restreignent l'utilisation.
 *
 * Cette distribution peut comprendre des composants developpes par des
 * tierces parties. Sun, Sun Microsystems, le logo Sun, Java et J2EE
 * sont des marques de fabrique ou des marques deposees de Sun
 * Microsystems, Inc. aux Etats-Unis et dans d'autres pays.
 */
package com.sun.cb;

import java.util.*;
import java.text.SimpleDateFormat;

/**
 * This class contains helper methods for dealing with
 * Date objects.
 */

public final class DateHelper {

    public static final Date getDate(int year, int month, int day,
        int hour, int minute) {

        // returns a Date with the specified time elements

        Calendar cal = new GregorianCalendar(year, intToCalendarMonth(month),
            day, hour, minute);

        return cal.getTime();

    } // getDate

    public static final Date getDate(int year, int month, int day) {

        // returns a Date with the specified time elements,
        // with the hour and minutes both set to 0 (midnight)

        Calendar cal = new GregorianCalendar(year, intToCalendarMonth(month),
            day);

        return cal.getTime();

    } // getDate

    static public final Date addDays(Date target, int days) {

        // returns a Date that is the sum of the target Date
        // and the specified number of days;
        // to subtract days from the target Date, the days
        // argument should be negative

        long msPerDay = 1000 * 60 * 60 * 24;
        long msTarget = target.getTime();
        long msSum = msTarget + (msPerDay * days);
        Date result = new Date();
        result.setTime(msSum);
        return result;
    } // addDays


    static public int dayDiff(Date first, Date second) {

        // returns the difference, in days, between the first
        // and second Date arguments

        long msPerDay = 1000 * 60 * 60 * 24;
        long diff = (first.getTime() / msPerDay) - (second.getTime() / msPerDay);
        Long convertLong = new Long(diff);
        return convertLong.intValue();
    } // dayDiff


    static public int getYear(Date date) {

        Calendar cal = new GregorianCalendar();
        cal.setTime(date);
        return cal.get(Calendar.YEAR);
    } // getYear

    static public int getMonth(Date date) {

        Calendar cal = new GregorianCalendar();
        cal.setTime(date);
        int calendarMonth = cal.get(Calendar.MONTH);
        return calendarMonthToInt(calendarMonth);
    } // getMonth

    static public int getDay(Date date) {

        Calendar cal = new GregorianCalendar();
        cal.setTime(date);
        return cal.get(Calendar.DAY_OF_MONTH);
    } // getDay

    static public int getHour(Date date) {

        Calendar cal = new GregorianCalendar();
        cal.setTime(date);
        return cal.get(Calendar.HOUR_OF_DAY);
    } // geHour

    static public int getMinute(Date date) {

        Calendar cal = new GregorianCalendar();
        cal.setTime(date);
        return cal.get(Calendar.MINUTE);
    } // geMinute

    private static int calendarMonthToInt(int calendarMonth) {

        if (calendarMonth == Calendar.JANUARY)
            return 1;
        else if (calendarMonth == Calendar.FEBRUARY)
            return 2;
        else if (calendarMonth == Calendar.MARCH)
            return 3;
        else if (calendarMonth == Calendar.APRIL)
            return 4;
        else if (calendarMonth == Calendar.MAY)
            return 5;
        else if (calendarMonth == Calendar.JUNE)
            return 6;
        else if (calendarMonth == Calendar.JULY)
            return 7;
        else if (calendarMonth == Calendar.AUGUST)
            return 8;
        else if (calendarMonth == Calendar.SEPTEMBER)
            return 9;
        else if (calendarMonth == Calendar.OCTOBER)
            return 10;
        else if (calendarMonth == Calendar.NOVEMBER)
            return 11;
        else if (calendarMonth == Calendar.DECEMBER)
            return 12;
        else
            return 1;

    } // calendarMonthToInt

    public static String format(Date date, String pattern) {

        // returns a String representation of the date argument,
        // formatted according to the pattern argument, which
        // has the same syntax as the argument of the SimpleDateFormat
        // class

        SimpleDateFormat formatter = new SimpleDateFormat(pattern);
        return formatter.format(date);

    } // format

    public static String format(Calendar cal, String pattern) {

        SimpleDateFormat formatter = new SimpleDateFormat(pattern);
        return formatter.format(calendarToDate(cal));

    } // format

    private static int intToCalendarMonth(int month) {

        if (month == 1)
           return Calendar.JANUARY;
        else if (month == 2)
           return Calendar.FEBRUARY;
        else if (month == 3)
           return Calendar.MARCH;
        else if (month == 4)
           return Calendar.APRIL;
        else if (month == 5)
           return Calendar.MAY;
        else if (month == 6)
           return Calendar.JUNE;
        else if (month == 7)
           return Calendar.JULY;
        else if (month == 8)
           return Calendar.AUGUST;
        else if (month == 9)
           return Calendar.SEPTEMBER;
        else if (month == 10)
           return Calendar.OCTOBER;
        else if (month == 11)
           return Calendar.NOVEMBER;
        else if (month == 12)
           return Calendar.DECEMBER;
        else
           return Calendar.JANUARY;

    } // intToCalendarMonth

   public static Calendar dateToCalendar(Date date) {

        Calendar cal = new GregorianCalendar();
        cal.setTime(date);
        return cal;

    } // dateToCalendar

   public static Date calendarToDate(Calendar cal) {

	   return cal.getTime();

   } // calendarToDate

} // class