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 /**

  * Copyright (c) 2012, Ben Fortuna

  * All rights reserved.

  *

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions

  * are met:

  *

  *  o Redistributions of source code must retain the above copyright

  * notice, this list of conditions and the following disclaimer.

  *

  *  o Redistributions in binary form must reproduce the above copyright

  * notice, this list of conditions and the following disclaimer in the

  * documentation and/or other materials provided with the distribution.

  *

  *  o Neither the name of Ben Fortuna nor the names of any other contributors

  * may be used to endorse or promote products derived from this software

  * without specific prior written permission.

  *

  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR

  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS

  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

  */

 package net.fortuna.ical4j.model;

 import java.text.DateFormat;

 import java.text.ParseException;

 import java.text.SimpleDateFormat;

 import java.util.Map;

 import java.util.WeakHashMap;

 import net.fortuna.ical4j.util.CompatibilityHints;

 import net.fortuna.ical4j.util.Dates;

 import net.fortuna.ical4j.util.TimeZones;

 import org.apache.commons.lang.builder.EqualsBuilder;

 import org.apache.commons.lang.builder.HashCodeBuilder;

 /**

  * $Id$

  * 

  * Created on 26/06/2005

  * 

  * Represents a time of day on a specific date.

  * 

  * <pre>

  * 4.3.5   Date-Time

  * 

  *    Value Name: DATE-TIME

  * 

  *    Purpose: This value type is used to identify values that specify a

  *    precise calendar date and time of day.

  * 

  *    Formal Definition: The value type is defined by the following

  *    notation:

  * 

  *      date-time  = date "T" time ;As specified in the date and time

  *                                 ;value definitions

  * 

  *    Description: If the property permits, multiple "date-time" values are

  *    specified as a COMMA character (US-ASCII decimal 44) separated list

  *    of values. No additional content value encoding (i.e., BACKSLASH

  *    character encoding) is defined for this value type.

  * 

  *    The "DATE-TIME" data type is used to identify values that contain a

  *    precise calendar date and time of day. The format is based on the

  *    [ISO 8601] complete representation, basic format for a calendar date

  *    and time of day. The text format is a concatenation of the "date",

  *    followed by the LATIN CAPITAL LETTER T character (US-ASCII decimal

  *    84) time designator, followed by the "time" format.

  * 

  *    The "DATE-TIME" data type expresses time values in three forms:

  * 

  *    The form of date and time with UTC offset MUST NOT be used. For

  *    example, the following is not valid for a date-time value:

  * 

  *      DTSTART:19980119T230000-0800       ;Invalid time format

  * 

  *    FORM #1: DATE WITH LOCAL TIME

  * 

  *    The date with local time form is simply a date-time value that does

  *    not contain the UTC designator nor does it reference a time zone. For

  *    example, the following represents Janurary 18, 1998, at 11 PM:

  * 

  *      DTSTART:19980118T230000

  * 

  *    Date-time values of this type are said to be "floating" and are not

  *    bound to any time zone in particular. They are used to represent the

  *    same hour, minute, and second value regardless of which time zone is

  *    currently being observed. For example, an event can be defined that

  *    indicates that an individual will be busy from 11:00 AM to 1:00 PM

  *    every day, no matter which time zone the person is in. In these

  *    cases, a local time can be specified. The recipient of an iCalendar

  *    object with a property value consisting of a local time, without any

  *    relative time zone information, SHOULD interpret the value as being

  *    fixed to whatever time zone the ATTENDEE is in at any given moment.

  *    This means that two ATTENDEEs, in different time zones, receiving the

  *    same event definition as a floating time, may be participating in the

  *    event at different actual times. Floating time SHOULD only be used

  *    where that is the reasonable behavior.

  * 

  *    In most cases, a fixed time is desired. To properly communicate a

  *    fixed time in a property value, either UTC time or local time with

  *    time zone reference MUST be specified.

  * 

  *    The use of local time in a DATE-TIME value without the TZID property

  *    parameter is to be interpreted as floating time, regardless of the

  *    existence of "VTIMEZONE" calendar components in the iCalendar object.

  * 

  *    FORM #2: DATE WITH UTC TIME

  * 

  *    The date with UTC time, or absolute time, is identified by a LATIN

  *    CAPITAL LETTER Z suffix character (US-ASCII decimal 90), the UTC

  *    designator, appended to the time value. For example, the following

  *    represents January 19, 1998, at 0700 UTC:

  * 

  *      DTSTART:19980119T070000Z

  * 

  *    The TZID property parameter MUST NOT be applied to DATE-TIME

  *    properties whose time values are specified in UTC.

  * 

  *    FORM #3: DATE WITH LOCAL TIME AND TIME ZONE REFERENCE

  * 

  *    The date and local time with reference to time zone information is

  *    identified by the use the TZID property parameter to reference the

  *    appropriate time zone definition. TZID is discussed in detail in the

  *    section on Time Zone. For example, the following represents 2 AM in

  *    New York on Janurary 19, 1998:

  * 

  *           DTSTART;TZID=US-Eastern:19980119T020000

  * 

  *    Example: The following represents July 14, 1997, at 1:30 PM in New

  *    York City in each of the three time formats, using the "DTSTART"

  *    property.

  * 

  *      DTSTART:19970714T133000            ;Local time

  *      DTSTART:19970714T173000Z           ;UTC time

  *      DTSTART;TZID=US-Eastern:19970714T133000    ;Local time and time

  *                         ; zone reference

  * 

  *    A time value MUST ONLY specify 60 seconds when specifying the

  *    periodic "leap second" in the time value. For example:

  * 

  *      COMPLETED:19970630T235960Z

  * </pre>

  * 

  * @author Ben Fortuna

  */

 public class DateTime extends Date {

 	private static final long serialVersionUID = -6407231357919440387L;

 	private static final String DEFAULT_PATTERN = "yyyyMMdd'T'HHmmss";

 	private static final String UTC_PATTERN = "yyyyMMdd'T'HHmmss'Z'";

 	private static final String RELAXED_PATTERN = "yyyyMMdd";

 	/**

 	 * Used for parsing times in a UTC date-time representation.

 	 */

 	private static final DateFormatCache UTC_FORMAT;

 	static {

 		final DateFormat format = new SimpleDateFormat(UTC_PATTERN);

 		format.setTimeZone(TimeZones.getUtcTimeZone());

 		format.setLenient(false);

 		UTC_FORMAT = new DateFormatCache(format);

 	}

 	/**

 	 * Used for parsing times in a local date-time representation.

 	 */

 	private static final DateFormatCache DEFAULT_FORMAT;

 	static {

 		final DateFormat format = new SimpleDateFormat(DEFAULT_PATTERN);

 		format.setLenient(false);

 		DEFAULT_FORMAT = new DateFormatCache(format);

 	}

 	private static final DateFormatCache LENIENT_DEFAULT_FORMAT;

 	static {

 		final DateFormat format = new SimpleDateFormat(DEFAULT_PATTERN);

 		LENIENT_DEFAULT_FORMAT = new DateFormatCache(format);

 	}

 	private static final DateFormatCache RELAXED_FORMAT;

 	static {

 		final DateFormat format = new SimpleDateFormat(RELAXED_PATTERN);

 		format.setLenient(false);

 		RELAXED_FORMAT = new DateFormatCache(format);

 	}

 	private Time time;

 	private TimeZone timezone;

 	/**

 	 * Default constructor.

 	 */

 	public DateTime() {

 		super(Dates.PRECISION_SECOND, java.util.TimeZone.getDefault());

 		this.time = new Time(getTime(), getFormat().getTimeZone());

 	}

 	/**

 	 * @param utc

 	 *            indicates if the date is in UTC time

 	 */

 	public DateTime(final boolean utc) {

 		this();

 		setUtc(utc);

 	}

 	/**

 	 * @param time

 	 *            a date-time value in milliseconds

 	 */

 	public DateTime(final long time) {

 		super(time, Dates.PRECISION_SECOND, java.util.TimeZone.getDefault());

 		this.time = new Time(time, getFormat().getTimeZone());

 	}

 	/**

 	 * @param date

 	 *            a date-time value

 	 */

 	public DateTime(final java.util.Date date) {

 		super(date.getTime(), Dates.PRECISION_SECOND, java.util.TimeZone.getDefault());

 		this.time = new Time(date.getTime(), getFormat().getTimeZone());

 		// copy timezone information if applicable..

 		if (date instanceof DateTime) {

 			final DateTime dateTime = (DateTime) date;

 			if (dateTime.isUtc()) {

 				setUtc(true);

 			} else {

 				setTimeZone(dateTime.getTimeZone());

 			}

 		}

 	}

 	/**

 	 * Constructs a new DateTime instance from parsing the specified string

 	 * representation in the default (local) timezone.

 	 * 

 	 * @param value

 	 *            a string representation of a date-time

 	 * @throws ParseException

 	 *             where the specified string is not a valid date-time

 	 */

 	public DateTime(final String value) throws ParseException {

 		this(value, null);

 		/*

 		 * long time = 0; try { synchronized (UTC_FORMAT) { time =

 		 * UTC_FORMAT.parse(value).getTime(); } setUtc(true); } catch

 		 * (ParseException pe) { synchronized (DEFAULT_FORMAT) {

 		 * DEFAULT_FORMAT.setTimeZone(getFormat().getTimeZone()); time =

 		 * DEFAULT_FORMAT.parse(value).getTime(); } this.time = new Time(time,

 		 * getFormat().getTimeZone()); } setTime(time);

 		 */

 	}

 	/**

 	 * Creates a new date-time instance from the specified value in the given

 	 * timezone. If a timezone is not specified, the default timezone (as

 	 * returned by {@link java.util.TimeZone#getDefault()}) is used.

 	 * 

 	 * @param value

 	 *            a string representation of a date-time

 	 * @param timezone

 	 *            the timezone for the date-time instance

 	 * @throws ParseException

 	 *             where the specified string is not a valid date-time

 	 */

 	public DateTime(final String value, final TimeZone timezone)

 			throws ParseException {

 		// setting the time to 0 since we are going to reset it anyway

 		super(0, Dates.PRECISION_SECOND, timezone != null ? timezone

 				: java.util.TimeZone.getDefault());

 		this.time = new Time(getTime(), getFormat().getTimeZone());

         try {

             if (value.endsWith("Z")) {

                 setTime(value, (DateFormat) UTC_FORMAT.get(), null);

                 setUtc(true);

             } else {

                 if (timezone != null) {

                     setTime(value, (DateFormat) DEFAULT_FORMAT.get(), timezone);

                 } else {

                     // Use lenient parsing for floating times. This is to

                     // overcome

                     // the problem of parsing VTimeZone dates that specify dates

                     // that the strict parser does not accept.

                     setTime(value, (DateFormat) LENIENT_DEFAULT_FORMAT.get(),

                             getFormat().getTimeZone());

                 }

                 setTimeZone(timezone);

             }

         } catch (ParseException pe) {

             if (CompatibilityHints.isHintEnabled(CompatibilityHints.KEY_RELAXED_PARSING)) {

                 setTime(value, (DateFormat) RELAXED_FORMAT.get(), timezone);

                 setTimeZone(timezone);

             } else {

                 throw pe;

             }

         }

     }

 	/**

 	 * @param value

 	 *            a string representation of a date-time

 	 * @param pattern

 	 *            a pattern to apply when parsing the date-time value

 	 * @param timezone

 	 *            the timezone for the date-time instance

 	 * @throws ParseException

 	 *             where the specified string is not a valid date-time

 	 */

 	public DateTime(String value, String pattern, TimeZone timezone)

 			throws ParseException {

 		// setting the time to 0 since we are going to reset it anyway

 		super(0, Dates.PRECISION_SECOND, timezone != null ? timezone

 				: java.util.TimeZone.getDefault());

 		this.time = new Time(getTime(), getFormat().getTimeZone());

 		final DateFormat format = CalendarDateFormatFactory

 				.getInstance(pattern);

 		setTime(value, format, timezone);

 	}

 	/**

 	 * @param value

 	 *            a string representation of a date-time

 	 * @param pattern

 	 *            a pattern to apply when parsing the date-time value

 	 * @param utc

 	 *            indicates whether the date-time is in UTC time

 	 * @throws ParseException

 	 *             where the specified string is not a valid date-time

 	 */

 	public DateTime(String value, String pattern, boolean utc)

 			throws ParseException {

                 // setting the time to 0 since we are going to reset it anyway

 		this(0);

 		final DateFormat format = CalendarDateFormatFactory

 				.getInstance(pattern);

 		if (utc) {

 			setTime(value, format,

 					((DateFormat) UTC_FORMAT.get()).getTimeZone());

 		} else {

 			setTime(value, format, null);

 		}

 		setUtc(utc);

 	}

 	/**

 	 * Internal set of time by parsing value string.

 	 * 

 	 * @param value

 	 * @param format

 	 *            a {@code DateFormat}, protected by the use of a ThreadLocal.

 	 * @param tz

 	 * @throws ParseException

 	 */

 	private void setTime(final String value, final DateFormat format,

 			final java.util.TimeZone tz) throws ParseException {

 		if (tz != null) {

 			format.setTimeZone(tz);

 		}

 		setTime(format.parse(value).getTime());

 	}

 	/**

 	 * {@inheritDoc}

 	 */

 	public final void setTime(final long time) {

 		super.setTime(time);

 		// need to check for null time due to Android java.util.Date(long)

 		// constructor

 		// calling this method..

 		if (this.time != null) {

 			this.time.setTime(time);

 		}

 	}

 	/**

 	 * @return Returns the utc.

 	 */

 	public final boolean isUtc() {

 		return time.isUtc();

 	}

 	/**

 	 * Updates this date-time to display in UTC time if the argument is true.

 	 * Otherwise, resets to the default timezone.

 	 * 

 	 * @param utc

 	 *            The utc to set.

 	 */

 	public final void setUtc(final boolean utc) {

 		// reset the timezone associated with this instance..

 		this.timezone = null;

 		if (utc) {

 			getFormat().setTimeZone(TimeZones.getUtcTimeZone());

 		} else {

 			resetTimeZone();

 		}

 		time = new Time(time, getFormat().getTimeZone(), utc);

 	}

 	/**

 	 * Sets the timezone associated with this date-time instance. If the

 	 * specified timezone is null, it will reset to the default timezone. If the

 	 * date-time instance is utc, it will turn into either a floating (no

 	 * timezone) date-time, or a date-time with a timezone.

 	 * 

 	 * @param timezone

 	 *            a timezone to apply to the instance

 	 */

 	public final void setTimeZone(final TimeZone timezone) {

 		this.timezone = timezone;

 		if (timezone != null) {

 			getFormat().setTimeZone(timezone);

 		} else {

 			resetTimeZone();

 		}

 		time = new Time(time, getFormat().getTimeZone(), false);

 	}

 	/**

 	 * Reset the timezone to default.

 	 */

 	private void resetTimeZone() {

 		// use GMT timezone to avoid daylight savings rules affecting floating

 		// time values..

 		getFormat().setTimeZone(TimeZone.getDefault());

 		// getFormat().setTimeZone(TimeZone.getTimeZone(TimeZones.GMT_ID));

 	}

 	/**

 	 * Returns the current timezone associated with this date-time value.

 	 * 

 	 * @return a Java timezone

 	 */

 	public final TimeZone getTimeZone() {

 		return timezone;

 	}

 	/**

 	 * {@inheritDoc}

 	 */

 	public final String toString() {

 		final StringBuffer b = new StringBuffer(super.toString());

 		b.append('T');

 		b.append(time.toString());

 		return b.toString();

 	}

 	/**

 	 * {@inheritDoc}

 	 */

 	public boolean equals(final Object arg0) {

 		// TODO: what about compareTo, before, after, etc.?

 		if (arg0 instanceof DateTime) {

 			return new EqualsBuilder().append(time, ((DateTime) arg0).time)

 					.isEquals();

 		}

 		return super.equals(arg0);

 	}

 	/**

 	 * {@inheritDoc}

 	 */

 	public int hashCode() {

 		return super.hashCode();

 	}

 	private static class DateFormatCache {

 		private final Map threadMap = new WeakHashMap();

 		private final DateFormat templateFormat;

 		private DateFormatCache(DateFormat dateFormat) {

 			this.templateFormat = dateFormat;

 		}

 		public DateFormat get() {

 			DateFormat dateFormat = (DateFormat) threadMap.get(Thread

 					.currentThread());

 			if (dateFormat == null) {

 				dateFormat = (DateFormat) templateFormat.clone();

 				threadMap.put(Thread.currentThread(), dateFormat);

 			}

 			return dateFormat;

 		}

 	}

 }