1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/net/fortuna/ical4j/util/Dates.java Tue Feb 10 18:12:00 2015 +0100
1.3 @@ -0,0 +1,315 @@
1.4 +/**
1.5 + * Copyright (c) 2012, Ben Fortuna
1.6 + * All rights reserved.
1.7 + *
1.8 + * Redistribution and use in source and binary forms, with or without
1.9 + * modification, are permitted provided that the following conditions
1.10 + * are met:
1.11 + *
1.12 + * o Redistributions of source code must retain the above copyright
1.13 + * notice, this list of conditions and the following disclaimer.
1.14 + *
1.15 + * o Redistributions in binary form must reproduce the above copyright
1.16 + * notice, this list of conditions and the following disclaimer in the
1.17 + * documentation and/or other materials provided with the distribution.
1.18 + *
1.19 + * o Neither the name of Ben Fortuna nor the names of any other contributors
1.20 + * may be used to endorse or promote products derived from this software
1.21 + * without specific prior written permission.
1.22 + *
1.23 + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1.24 + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1.25 + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1.26 + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
1.27 + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
1.28 + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
1.29 + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
1.30 + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
1.31 + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
1.32 + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
1.33 + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.34 + */
1.35 +package net.fortuna.ical4j.util;
1.36 +
1.37 +import java.text.MessageFormat;
1.38 +import java.util.ArrayList;
1.39 +import java.util.Calendar;
1.40 +import java.util.List;
1.41 +import java.util.TimeZone;
1.42 +
1.43 +import net.fortuna.ical4j.model.Date;
1.44 +import net.fortuna.ical4j.model.DateTime;
1.45 +import net.fortuna.ical4j.model.parameter.Value;
1.46 +
1.47 +/**
1.48 + * $Id$
1.49 + *
1.50 + * Created on 26/06/2005
1.51 + *
1.52 + * Implements a collection of utility methods relevant to date processing.
1.53 + *
1.54 + * @author Ben Fortuna
1.55 + */
1.56 +public final class Dates {
1.57 +
1.58 + /**
1.59 + * Number of milliseconds in one second.
1.60 + */
1.61 + public static final long MILLIS_PER_SECOND = 1000;
1.62 +
1.63 + /**
1.64 + * Number of milliseconds in one minute.
1.65 + */
1.66 + public static final long MILLIS_PER_MINUTE = 60000;
1.67 +
1.68 + /**
1.69 + * Number of milliseconds in one hour.
1.70 + */
1.71 + public static final long MILLIS_PER_HOUR = 3600000;
1.72 +
1.73 + /**
1.74 + * Number of milliseconds in one day.
1.75 + */
1.76 + public static final long MILLIS_PER_DAY = 86400000;
1.77 +
1.78 + /**
1.79 + * Number of milliseconds in one week.
1.80 + */
1.81 + public static final long MILLIS_PER_WEEK = 604800000;
1.82 +
1.83 + /**
1.84 + * Number of days in one week.
1.85 + */
1.86 + public static final int DAYS_PER_WEEK = 7;
1.87 +
1.88 + /**
1.89 + * Constant indicating precision to the second.
1.90 + */
1.91 + public static final int PRECISION_SECOND = 0;
1.92 +
1.93 + /**
1.94 + * Constant indicating precision to the day.
1.95 + */
1.96 + public static final int PRECISION_DAY = 1;
1.97 +
1.98 + /**
1.99 + * Maximum number of weeks per year.
1.100 + */
1.101 + public static final int MAX_WEEKS_PER_YEAR = 53;
1.102 +
1.103 + /**
1.104 + * Maximum number of days per year.
1.105 + */
1.106 + public static final int MAX_DAYS_PER_YEAR = 366;
1.107 +
1.108 + /**
1.109 + * Maximum number of days per month.
1.110 + */
1.111 + public static final int MAX_DAYS_PER_MONTH = 31;
1.112 +
1.113 + private static final String INVALID_WEEK_MESSAGE = "Invalid week number [{0}]";
1.114 +
1.115 + private static final String INVALID_YEAR_DAY_MESSAGE = "Invalid year day [{0}]";
1.116 +
1.117 + private static final String INVALID_MONTH_DAY_MESSAGE = "Invalid month day [{0}]";
1.118 +
1.119 + /**
1.120 + * Constructor made private to prevent instantiation.
1.121 + */
1.122 + private Dates() {
1.123 + }
1.124 +
1.125 + /**
1.126 + * Returns the absolute week number for the year specified by the
1.127 + * supplied date. Note that a value of zero (0) is invalid for the
1.128 + * weekNo parameter and an <code>IllegalArgumentException</code>
1.129 + * will be thrown.
1.130 + * @param date a date instance representing a week of the year
1.131 + * @param weekNo a week number offset
1.132 + * @return the absolute week of the year for the specified offset
1.133 + */
1.134 + public static int getAbsWeekNo(final java.util.Date date, final int weekNo) {
1.135 + if (weekNo == 0 || weekNo < -MAX_WEEKS_PER_YEAR || weekNo > MAX_WEEKS_PER_YEAR) {
1.136 + throw new IllegalArgumentException(MessageFormat.format(INVALID_WEEK_MESSAGE,
1.137 + new Object[] {new Integer(weekNo)}));
1.138 + }
1.139 + if (weekNo > 0) {
1.140 + return weekNo;
1.141 + }
1.142 + final Calendar cal = Calendar.getInstance();
1.143 + cal.setTime(date);
1.144 + final int year = cal.get(Calendar.YEAR);
1.145 + // construct a list of possible week numbers..
1.146 + final List weeks = new ArrayList();
1.147 + cal.set(Calendar.WEEK_OF_YEAR, 1);
1.148 + while (cal.get(Calendar.YEAR) == year) {
1.149 + weeks.add(new Integer(cal.get(Calendar.WEEK_OF_YEAR)));
1.150 + cal.add(Calendar.WEEK_OF_YEAR, 1);
1.151 + }
1.152 + return ((Integer) weeks.get(weeks.size() + weekNo)).intValue();
1.153 + }
1.154 +
1.155 + /**
1.156 + * Returns the absolute year day for the year specified by the
1.157 + * supplied date. Note that a value of zero (0) is invalid for the
1.158 + * yearDay parameter and an <code>IllegalArgumentException</code>
1.159 + * will be thrown.
1.160 + * @param date a date instance representing a day of the year
1.161 + * @param yearDay a day of year offset
1.162 + * @return the absolute day of month for the specified offset
1.163 + */
1.164 + public static int getAbsYearDay(final java.util.Date date, final int yearDay) {
1.165 + if (yearDay == 0 || yearDay < -MAX_DAYS_PER_YEAR || yearDay > MAX_DAYS_PER_YEAR) {
1.166 + throw new IllegalArgumentException(MessageFormat.format(INVALID_YEAR_DAY_MESSAGE,
1.167 + new Object[] {new Integer(yearDay)}));
1.168 + }
1.169 + if (yearDay > 0) {
1.170 + return yearDay;
1.171 + }
1.172 + final Calendar cal = Calendar.getInstance();
1.173 + cal.setTime(date);
1.174 + final int year = cal.get(Calendar.YEAR);
1.175 + // construct a list of possible year days..
1.176 + final List days = new ArrayList();
1.177 + cal.set(Calendar.DAY_OF_YEAR, 1);
1.178 + while (cal.get(Calendar.YEAR) == year) {
1.179 + days.add(new Integer(cal.get(Calendar.DAY_OF_YEAR)));
1.180 + cal.add(Calendar.DAY_OF_YEAR, 1);
1.181 + }
1.182 + return ((Integer) days.get(days.size() + yearDay)).intValue();
1.183 + }
1.184 +
1.185 + /**
1.186 + * Returns the absolute month day for the month specified by the
1.187 + * supplied date. Note that a value of zero (0) is invalid for the
1.188 + * monthDay parameter and an <code>IllegalArgumentException</code>
1.189 + * will be thrown.
1.190 + * @param date a date instance representing a day of the month
1.191 + * @param monthDay a day of month offset
1.192 + * @return the absolute day of month for the specified offset
1.193 + */
1.194 + public static int getAbsMonthDay(final java.util.Date date, final int monthDay) {
1.195 + if (monthDay == 0 || monthDay < -MAX_DAYS_PER_MONTH || monthDay > MAX_DAYS_PER_MONTH) {
1.196 + throw new IllegalArgumentException(MessageFormat.format(INVALID_MONTH_DAY_MESSAGE,
1.197 + new Object[] {new Integer(monthDay)}));
1.198 + }
1.199 + if (monthDay > 0) {
1.200 + return monthDay;
1.201 + }
1.202 + final Calendar cal = Calendar.getInstance();
1.203 + cal.setTime(date);
1.204 + final int month = cal.get(Calendar.MONTH);
1.205 + // construct a list of possible month days..
1.206 + final List days = new ArrayList();
1.207 + cal.set(Calendar.DAY_OF_MONTH, 1);
1.208 + while (cal.get(Calendar.MONTH) == month) {
1.209 + days.add(new Integer(cal.get(Calendar.DAY_OF_MONTH)));
1.210 + cal.add(Calendar.DAY_OF_MONTH, 1);
1.211 + }
1.212 + return ((Integer) days.get(days.size() + monthDay)).intValue();
1.213 + }
1.214 +
1.215 + /**
1.216 + * Returns a new date instance of the specified type. If no type is
1.217 + * specified a DateTime instance is returned.
1.218 + * @param date a seed Java date instance
1.219 + * @param type the type of date instance
1.220 + * @return an instance of <code>net.fortuna.ical4j.model.Date</code>
1.221 + */
1.222 + public static Date getInstance(final java.util.Date date, final Value type) {
1.223 + if (Value.DATE.equals(type)) {
1.224 + return new Date(date);
1.225 + }
1.226 + return new DateTime(date);
1.227 + }
1.228 +
1.229 + /**
1.230 + * Returns an instance of <code>java.util.Calendar</code> that is suitably
1.231 + * initialised for working with the specified date.
1.232 + * @param date a date instance
1.233 + * @return a <code>java.util.Calendar</code>
1.234 + */
1.235 + public static Calendar getCalendarInstance(final Date date) {
1.236 + Calendar instance = null;
1.237 + if (date instanceof DateTime) {
1.238 + final DateTime dateTime = (DateTime) date;
1.239 + if (dateTime.getTimeZone() != null) {
1.240 + instance = Calendar.getInstance(dateTime.getTimeZone());
1.241 + }
1.242 + else if (dateTime.isUtc()) {
1.243 + instance = Calendar.getInstance(TimeZones.getUtcTimeZone());
1.244 + }
1.245 + else {
1.246 + // a date-time without a timezone but not UTC is floating
1.247 + instance = Calendar.getInstance();
1.248 + }
1.249 + }
1.250 + else {
1.251 + instance = Calendar.getInstance(TimeZones.getDateTimeZone());
1.252 + }
1.253 + return instance;
1.254 + }
1.255 +
1.256 + /**
1.257 + * @param time the time value to round
1.258 + * @param precision the rounding precision
1.259 + * @return a round time value
1.260 + * @deprecated It is not all that useful to perform rounding without specifying an
1.261 + * explicit timezone.
1.262 + */
1.263 + public static long round(final long time, final int precision) {
1.264 + return round(time, precision, TimeZone.getDefault());
1.265 +// return round(time, precision, TimeZone.getTimeZone(TimeZones.UTC_ID));
1.266 + /*
1.267 + long newTime = time;
1.268 + if (precision == PRECISION_DAY) {
1.269 + long remainder = newTime%(1000*60*60); // get the mod remainder using milliseconds*seconds*min
1.270 + newTime = newTime-remainder;
1.271 + // remove the remainder from the time to clear the milliseconds, seconds and minutes
1.272 + }
1.273 + else if (precision == PRECISION_SECOND) {
1.274 + long remainder = newTime%(1000); // get the mod remainder using milliseconds
1.275 + newTime = newTime-remainder; // remove the remainder from the time to clear the milliseconds
1.276 + }
1.277 + return newTime;
1.278 + */
1.279 + }
1.280 +
1.281 + /**
1.282 + * Rounds a time value to remove any precision smaller than specified.
1.283 + * @param time the time value to round
1.284 + * @param precision the rounding precision
1.285 + * @param tz the timezone of the rounded value
1.286 + * @return a round time value
1.287 + */
1.288 + public static long round(final long time, final int precision, final TimeZone tz) {
1.289 + if ((precision == PRECISION_SECOND) && ((time % Dates.MILLIS_PER_SECOND) == 0)) {
1.290 + return time;
1.291 + }
1.292 + final Calendar cal = Calendar.getInstance(tz);
1.293 + cal.setTimeInMillis(time);
1.294 + if (precision == PRECISION_DAY) {
1.295 +// return (long) Math.floor(time / (double) Dates.MILLIS_PER_DAY) * Dates.MILLIS_PER_DAY;
1.296 + cal.set(Calendar.HOUR_OF_DAY, 0);
1.297 + cal.clear(Calendar.MINUTE);
1.298 + cal.clear(Calendar.SECOND);
1.299 + cal.clear(Calendar.MILLISECOND);
1.300 + }
1.301 + else if (precision == PRECISION_SECOND) {
1.302 +// return (long) Math.floor(time / (double) Dates.MILLIS_PER_SECOND) * Dates.MILLIS_PER_SECOND;
1.303 + cal.clear(Calendar.MILLISECOND);
1.304 + }
1.305 + // unrecognised precision..
1.306 + return cal.getTimeInMillis();
1.307 + }
1.308 +
1.309 + /**
1.310 + * Returns the {@code System.currentTimeMillis()}, rounded to the second.
1.311 + * <p>By doing a rough rounding here, we avoid an expensive java.util.Calendar based
1.312 + * rounding later on.</p>
1.313 + * @return the current time in millisec.
1.314 + */
1.315 + public static long getCurrentTimeRounded() {
1.316 + return (long) Math.floor(System.currentTimeMillis() / (double) Dates.MILLIS_PER_SECOND) * Dates.MILLIS_PER_SECOND;
1.317 + }
1.318 +}
