2 Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004, 2005 Free Software Foundation, Inc.
4 This file is part of GNU Classpath.
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; see the file COPYING. If not, write to the
18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library. Thus, the terms and
23 conditions of the GNU General Public License cover the whole
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module. An independent module is a module which is not derived from
33 or based on this library. If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so. If you do not wish to do so, delete this
36 exception statement from your version. */
41 import java
.io
.IOException
;
42 import java
.io
.ObjectInputStream
;
43 import java
.io
.ObjectOutputStream
;
44 import java
.io
.Serializable
;
45 import java
.lang
.reflect
.Constructor
;
46 import java
.lang
.reflect
.InvocationTargetException
;
49 * This class is an abstract base class for Calendars, which can be
50 * used to convert between <code>Date</code> objects and a set of
51 * integer fields which represent <code>YEAR</code>,
52 * <code>MONTH</code>, <code>DAY</code>, etc. The <code>Date</code>
53 * object represents a time in milliseconds since the Epoch. <br>
55 * This class is locale sensitive. To get the Object matching the
56 * current locale you can use <code>getInstance</code>. You can even provide
57 * a locale or a timezone. <code>getInstance</code> returns currently
58 * a <code>GregorianCalendar</code> for the current date. <br>
60 * If you want to convert a date from the Year, Month, Day, DayOfWeek,
61 * etc. Representation to a <code>Date</code>-Object, you can create
62 * a new Calendar with <code>getInstance()</code>,
63 * <code>clear()</code> all fields, <code>set(int,int)</code> the
64 * fields you need and convert it with <code>getTime()</code>. <br>
66 * If you want to convert a <code>Date</code>-object to the Calendar
67 * representation, create a new Calendar, assign the
68 * <code>Date</code>-Object with <code>setTime()</code>, and read the
69 * fields with <code>get(int)</code>. <br>
71 * When computing the date from time fields, it may happen, that there
72 * are either two few fields set, or some fields are inconsistent. This
73 * cases will handled in a calendar specific way. Missing fields are
74 * replaced by the fields of the epoch: 1970 January 1 00:00. <br>
76 * To understand, how the day of year is computed out of the fields
77 * look at the following table. It is traversed from top to bottom,
78 * and for the first line all fields are set, that line is used to
79 * compute the day. <br>
82 <pre>month + day_of_month
83 month + week_of_month + day_of_week
84 month + day_of_week_of_month + day_of_week
86 day_of_week + week_of_year</pre>
88 * The hour_of_day-field takes precedence over the ampm and
89 * hour_of_ampm fields. <br>
91 * <STRONG>Note:</STRONG> This can differ for non-Gregorian calendar. <br>
93 * To convert a calendar to a human readable form and vice versa, use
94 * the <code>java.text.DateFormat</code> class. <br>
96 * Other useful things you can do with an calendar, is
97 * <code>roll</code>ing fields (that means increase/decrease a
98 * specific field by one, propagating overflows), or
99 * <code>add</code>ing/substracting a fixed amount to a field.
102 * @see GregorianCalendar
104 * @see java.text.DateFormat
106 public abstract class Calendar
implements Serializable
, Cloneable
109 * Constant representing the era time field.
111 public static final int ERA
= 0;
114 * Constant representing the year time field.
116 public static final int YEAR
= 1;
119 * Constant representing the month time field. This field
120 * should contain one of the JANUARY,...,DECEMBER constants below.
122 public static final int MONTH
= 2;
125 * Constant representing the week of the year field.
126 * @see #setFirstDayOfWeek(int)
128 public static final int WEEK_OF_YEAR
= 3;
131 * Constant representing the week of the month time field.
132 * @see #setFirstDayOfWeek(int)
134 public static final int WEEK_OF_MONTH
= 4;
137 * Constant representing the day time field, synonym for DAY_OF_MONTH.
139 public static final int DATE
= 5;
142 * Constant representing the day time field.
144 public static final int DAY_OF_MONTH
= 5;
147 * Constant representing the day of year time field. This is
148 * 1 for the first day in month.
150 public static final int DAY_OF_YEAR
= 6;
153 * Constant representing the day of week time field. This field
154 * should contain one of the SUNDAY,...,SATURDAY constants below.
156 public static final int DAY_OF_WEEK
= 7;
159 * Constant representing the day-of-week-in-month field. For
160 * instance this field contains 2 for the second thursday in a
161 * month. If you give a negative number here, the day will count
162 * from the end of the month.
164 public static final int DAY_OF_WEEK_IN_MONTH
= 8;
167 * Constant representing the part of the day for 12-hour clock. This
168 * should be one of AM or PM.
170 public static final int AM_PM
= 9;
173 * Constant representing the hour time field for 12-hour clock.
175 public static final int HOUR
= 10;
178 * Constant representing the hour of day time field for 24-hour clock.
180 public static final int HOUR_OF_DAY
= 11;
183 * Constant representing the minute of hour time field.
185 public static final int MINUTE
= 12;
188 * Constant representing the second time field.
190 public static final int SECOND
= 13;
193 * Constant representing the millisecond time field.
195 public static final int MILLISECOND
= 14;
198 * Constant representing the time zone offset time field for the
199 * time given in the other fields. It is measured in
200 * milliseconds. The default is the offset of the time zone.
202 public static final int ZONE_OFFSET
= 15;
205 * Constant representing the daylight saving time offset in
206 * milliseconds. The default is the value given by the time zone.
208 public static final int DST_OFFSET
= 16;
211 * Number of time fields.
213 public static final int FIELD_COUNT
= 17;
216 * Constant representing Sunday.
218 public static final int SUNDAY
= 1;
221 * Constant representing Monday.
223 public static final int MONDAY
= 2;
226 * Constant representing Tuesday.
228 public static final int TUESDAY
= 3;
231 * Constant representing Wednesday.
233 public static final int WEDNESDAY
= 4;
236 * Constant representing Thursday.
238 public static final int THURSDAY
= 5;
241 * Constant representing Friday.
243 public static final int FRIDAY
= 6;
246 * Constant representing Saturday.
248 public static final int SATURDAY
= 7;
251 * Constant representing January.
253 public static final int JANUARY
= 0;
256 * Constant representing February.
258 public static final int FEBRUARY
= 1;
261 * Constant representing March.
263 public static final int MARCH
= 2;
266 * Constant representing April.
268 public static final int APRIL
= 3;
271 * Constant representing May.
273 public static final int MAY
= 4;
276 * Constant representing June.
278 public static final int JUNE
= 5;
281 * Constant representing July.
283 public static final int JULY
= 6;
286 * Constant representing August.
288 public static final int AUGUST
= 7;
291 * Constant representing September.
293 public static final int SEPTEMBER
= 8;
296 * Constant representing October.
298 public static final int OCTOBER
= 9;
301 * Constant representing November.
303 public static final int NOVEMBER
= 10;
306 * Constant representing December.
308 public static final int DECEMBER
= 11;
311 * Constant representing Undecimber. This is an artificial name useful
312 * for lunar calendars.
314 public static final int UNDECIMBER
= 12;
317 * Useful constant for 12-hour clock.
319 public static final int AM
= 0;
322 * Useful constant for 12-hour clock.
324 public static final int PM
= 1;
327 * The time fields. The array is indexed by the constants YEAR to
331 protected int[] fields
= new int[FIELD_COUNT
];
334 * The flags which tell if the fields above have a value.
337 protected boolean[] isSet
= new boolean[FIELD_COUNT
];
340 * The time in milliseconds since the epoch.
346 * Tells if the above field has a valid value.
349 protected boolean isTimeSet
;
352 * Tells if the fields have a valid value. This superseeds the isSet
356 protected boolean areFieldsSet
;
359 * The time zone of this calendar. Used by sub classes to do UTC / local
360 * time conversion. Sub classes can access this field with getTimeZone().
363 private TimeZone zone
;
366 * Specifies if the date/time interpretation should be lenient.
367 * If the flag is set, a date such as "February 30, 1996" will be
368 * treated as the 29th day after the February 1. If this flag
369 * is false, such dates will cause an exception.
372 private boolean lenient
;
375 * Sets what the first day of week is. This is used for
376 * WEEK_OF_MONTH and WEEK_OF_YEAR fields.
379 private int firstDayOfWeek
;
382 * Sets how many days are required in the first week of the year.
383 * If the first day of the year should be the first week you should
384 * set this value to 1. If the first week must be a full week, set
388 private int minimalDaysInFirstWeek
;
391 * Is set to true if DST_OFFSET is explicitly set. In that case
392 * it's value overrides the value computed from the current
393 * time and the timezone.
395 private boolean explicitDSTOffset
= false;
398 * The version of the serialized data on the stream.
399 * <dl><dt>0 or not present</dt>
400 * <dd> JDK 1.1.5 or later.</dd>
402 * <dd>JDK 1.1.6 or later. This always writes a correct `time' value
403 * on the stream, as well as the other fields, to be compatible with
404 * earlier versions</dd></dl>
408 private int serialVersionOnStream
= 1;
411 * XXX - I have not checked the compatibility. The documentation of
412 * the serialized-form is quite hairy...
414 static final long serialVersionUID
= -1807547505821590642L;
417 * The name of the resource bundle. Used only by getBundle()
419 private static final String bundleName
= "gnu.java.locale.Calendar";
422 * get resource bundle:
423 * The resources should be loaded via this method only. Iff an application
424 * uses this method, the resourcebundle is required.
426 private static ResourceBundle
getBundle(Locale locale
)
428 return ResourceBundle
.getBundle(bundleName
, locale
,
429 ClassLoader
.getSystemClassLoader());
433 * Constructs a new Calendar with the default time zone and the default
438 this(TimeZone
.getDefault(), Locale
.getDefault());
442 * Constructs a new Calendar with the given time zone and the given
444 * @param zone a time zone.
445 * @param locale a locale.
447 protected Calendar(TimeZone zone
, Locale locale
)
452 ResourceBundle rb
= getBundle(locale
);
454 firstDayOfWeek
= ((Integer
) rb
.getObject("firstDayOfWeek")).intValue();
455 minimalDaysInFirstWeek
= ((Integer
) rb
.getObject("minimalDaysInFirstWeek"))
461 * Creates a calendar representing the actual time, using the default
462 * time zone and locale.
464 public static synchronized Calendar
getInstance()
466 return getInstance(TimeZone
.getDefault(), Locale
.getDefault());
470 * Creates a calendar representing the actual time, using the given
471 * time zone and the default locale.
472 * @param zone a time zone.
474 public static synchronized Calendar
getInstance(TimeZone zone
)
476 return getInstance(zone
, Locale
.getDefault());
480 * Creates a calendar representing the actual time, using the default
481 * time zone and the given locale.
482 * @param locale a locale.
484 public static synchronized Calendar
getInstance(Locale locale
)
486 return getInstance(TimeZone
.getDefault(), locale
);
490 * Cache of locale->calendar-class mappings. This avoids having to do a ResourceBundle
491 * lookup for every getInstance call.
493 private static HashMap cache
= new HashMap();
495 /** Preset argument types for calendar-class constructor lookup. */
496 private static Class
[] ctorArgTypes
= new Class
[]
498 TimeZone
.class, Locale
.class
502 * Creates a calendar representing the actual time, using the given
503 * time zone and locale.
504 * @param zone a time zone.
505 * @param locale a locale.
507 public static synchronized Calendar
getInstance(TimeZone zone
, Locale locale
)
509 Class calendarClass
= (Class
) cache
.get(locale
);
510 Throwable exception
= null;
514 if (calendarClass
== null)
516 ResourceBundle rb
= getBundle(locale
);
517 String calendarClassName
= rb
.getString("calendarClass");
519 if (calendarClassName
!= null)
521 calendarClass
= Class
.forName(calendarClassName
);
522 if (Calendar
.class.isAssignableFrom(calendarClass
))
523 cache
.put(locale
, calendarClass
);
527 // GregorianCalendar is by far the most common case. Optimize by
528 // avoiding reflection.
529 if (calendarClass
== GregorianCalendar
.class)
530 return new GregorianCalendar(zone
, locale
);
532 if (Calendar
.class.isAssignableFrom(calendarClass
))
534 Constructor ctor
= calendarClass
.getConstructor(ctorArgTypes
);
535 return (Calendar
) ctor
.newInstance(new Object
[] { zone
, locale
});
538 catch (ClassNotFoundException ex
)
542 catch (IllegalAccessException ex
)
546 catch (NoSuchMethodException ex
)
550 catch (InstantiationException ex
)
554 catch (InvocationTargetException ex
)
559 throw new RuntimeException("Error instantiating calendar for locale "
560 + locale
, exception
);
564 * Gets the set of locales for which a Calendar is available.
565 * @exception MissingResourceException if locale data couldn't be found.
566 * @return the set of locales.
568 public static synchronized Locale
[] getAvailableLocales()
570 ResourceBundle rb
= getBundle(new Locale("", ""));
571 return (Locale
[]) rb
.getObject("availableLocales");
575 * Converts the time field values (<code>fields</code>) to
576 * milliseconds since the epoch UTC (<code>time</code>). Override
577 * this method if you write your own Calendar. */
578 protected abstract void computeTime();
581 * Converts the milliseconds since the epoch UTC
582 * (<code>time</code>) to time fields
583 * (<code>fields</code>). Override this method if you write your
586 protected abstract void computeFields();
589 * Converts the time represented by this object to a
590 * <code>Date</code>-Object.
593 public final Date
getTime()
597 return new Date(time
);
601 * Sets this Calendar's time to the given Date. All time fields
602 * are invalidated by this method.
604 public final void setTime(Date date
)
606 setTimeInMillis(date
.getTime());
610 * Returns the time represented by this Calendar.
611 * @return the time in milliseconds since the epoch.
612 * @specnote This was made public in 1.4.
614 public long getTimeInMillis()
622 * Sets this Calendar's time to the given Time. All time fields
623 * are invalidated by this method.
624 * @param time the time in milliseconds since the epoch
625 * @specnote This was made public in 1.4.
627 public void setTimeInMillis(long time
)
636 * Gets the value of the specified field. They are recomputed
637 * if they are invalid.
638 * @param field the time field. One of the time field constants.
639 * @return the value of the specified field
640 * @throws ArrayIndexOutOfBoundsException if the field is outside
641 * the valid range. The value of field must be >= 0 and
642 * <= <code>FIELD_COUNT</code>.
643 * @specnote Not final since JDK 1.4
645 public int get(int field
)
647 // If the requested field is invalid, force all fields to be recomputed.
649 areFieldsSet
= false;
651 return fields
[field
];
655 * Gets the value of the specified field. This method doesn't
656 * recompute the fields, if they are invalid.
657 * @param field the time field. One of the time field constants.
658 * @return the value of the specified field, undefined if
659 * <code>areFieldsSet</code> or <code>isSet[field]</code> is false.
660 * @throws ArrayIndexOutOfBoundsException if the field is outside
661 * the valid range. The value of field must be >= 0 and
662 * <= <code>FIELD_COUNT</code>.
664 protected final int internalGet(int field
)
666 return fields
[field
];
670 * Sets the time field with the given value. This does invalidate
671 * the time in milliseconds.
672 * @param field the time field. One of the time field constants
673 * @param value the value to be set.
674 * @throws ArrayIndexOutOfBoundsException if field is outside
675 * the valid range. The value of field must be >= 0 and
676 * <= <code>FIELD_COUNT</code>.
677 * @specnote Not final since JDK 1.4
679 public void set(int field
, int value
)
682 for (int i
= 0; i
< FIELD_COUNT
; i
++)
685 fields
[field
] = value
;
688 // The five valid date patterns, in order of priority
689 // 1 YEAR + MONTH + DAY_OF_MONTH
690 // 2 YEAR + MONTH + WEEK_OF_MONTH + DAY_OF_WEEK
691 // 3 YEAR + MONTH + DAY_OF_WEEK_IN_MONTH + DAY_OF_WEEK
692 // 4 YEAR + DAY_OF_YEAR
693 // 5 YEAR + DAY_OF_WEEK + WEEK_OF_YEAR
696 case MONTH
: // pattern 1,2 or 3
697 isSet
[DAY_OF_YEAR
] = false;
698 isSet
[WEEK_OF_YEAR
] = false;
700 case DAY_OF_MONTH
: // pattern 1
703 isSet
[WEEK_OF_MONTH
] = true;
704 isSet
[DAY_OF_WEEK
] = false;
705 isSet
[DAY_OF_WEEK_IN_MONTH
] = false;
706 isSet
[DAY_OF_YEAR
] = false;
707 isSet
[WEEK_OF_YEAR
] = false;
709 case WEEK_OF_MONTH
: // pattern 2
710 if (! isSet
[DAY_OF_WEEK
])
711 fields
[DAY_OF_WEEK
] = getFirstDayOfWeek();
714 isSet
[DAY_OF_WEEK
] = true;
715 isSet
[DAY_OF_MONTH
] = false;
716 isSet
[DAY_OF_WEEK_IN_MONTH
] = false;
717 isSet
[DAY_OF_YEAR
] = false;
718 isSet
[WEEK_OF_YEAR
] = false;
720 case DAY_OF_WEEK_IN_MONTH
: // pattern 3
721 if (! isSet
[DAY_OF_WEEK
])
722 fields
[DAY_OF_WEEK
] = getFirstDayOfWeek();
725 isSet
[DAY_OF_WEEK
] = true;
726 isSet
[DAY_OF_YEAR
] = false;
727 isSet
[DAY_OF_MONTH
] = false;
728 isSet
[WEEK_OF_MONTH
] = false;
729 isSet
[WEEK_OF_YEAR
] = false;
731 case DAY_OF_YEAR
: // pattern 4
733 isSet
[MONTH
] = false;
734 isSet
[WEEK_OF_MONTH
] = false;
735 isSet
[DAY_OF_MONTH
] = false;
736 isSet
[DAY_OF_WEEK
] = false;
737 isSet
[WEEK_OF_YEAR
] = false;
738 isSet
[DAY_OF_WEEK_IN_MONTH
] = false;
740 case WEEK_OF_YEAR
: // pattern 5
741 if (! isSet
[DAY_OF_WEEK
])
742 fields
[DAY_OF_WEEK
] = getFirstDayOfWeek();
744 isSet
[DAY_OF_WEEK
] = true;
745 isSet
[MONTH
] = false;
746 isSet
[DAY_OF_MONTH
] = false;
747 isSet
[WEEK_OF_MONTH
] = false;
748 isSet
[DAY_OF_YEAR
] = false;
749 isSet
[DAY_OF_WEEK_IN_MONTH
] = false;
753 isSet
[HOUR_OF_DAY
] = false;
756 isSet
[AM_PM
] = false;
761 isSet
[HOUR_OF_DAY
] = false;
764 explicitDSTOffset
= true;
767 // May have crossed over a DST boundary.
768 if (! explicitDSTOffset
&& (field
!= DST_OFFSET
&& field
!= ZONE_OFFSET
))
769 isSet
[DST_OFFSET
] = false;
773 * Sets the fields for year, month, and date
774 * @param year the year.
775 * @param month the month, one of the constants JANUARY..UNDICEMBER.
776 * @param date the day of the month
778 public final void set(int year
, int month
, int date
)
782 fields
[MONTH
] = month
;
784 isSet
[YEAR
] = isSet
[MONTH
] = isSet
[DATE
] = true;
785 isSet
[WEEK_OF_YEAR
] = false;
786 isSet
[DAY_OF_YEAR
] = false;
787 isSet
[WEEK_OF_MONTH
] = false;
788 isSet
[DAY_OF_WEEK
] = false;
789 isSet
[DAY_OF_WEEK_IN_MONTH
] = false;
792 if (! explicitDSTOffset
)
793 isSet
[DST_OFFSET
] = false; // May have crossed a DST boundary.
797 * Sets the fields for year, month, date, hour, and minute
798 * @param year the year.
799 * @param month the month, one of the constants JANUARY..UNDICEMBER.
800 * @param date the day of the month
801 * @param hour the hour of day.
802 * @param minute the minute.
804 public final void set(int year
, int month
, int date
, int hour
, int minute
)
806 set(year
, month
, date
);
807 fields
[HOUR_OF_DAY
] = hour
;
808 fields
[MINUTE
] = minute
;
809 isSet
[HOUR_OF_DAY
] = isSet
[MINUTE
] = true;
810 isSet
[AM_PM
] = false;
815 * Sets the fields for year, month, date, hour, and minute
816 * @param year the year.
817 * @param month the month, one of the constants JANUARY..UNDICEMBER.
818 * @param date the day of the month
819 * @param hour the hour of day.
820 * @param minute the minute.
821 * @param second the second.
823 public final void set(int year
, int month
, int date
, int hour
, int minute
,
826 set(year
, month
, date
, hour
, minute
);
827 fields
[SECOND
] = second
;
828 isSet
[SECOND
] = true;
832 * Clears the values of all the time fields.
834 public final void clear()
837 areFieldsSet
= false;
838 int zoneOffs
= zone
.getRawOffset();
841 1, 1970, JANUARY
, 1, 1, 1, 1, THURSDAY
, 1, AM
, 0, 0, 0,
845 for (int i
= 0; i
< FIELD_COUNT
; i
++)
850 * Clears the values of the specified time field.
851 * @param field the time field. One of the time field constants.
852 * @throws ArrayIndexOutOfBoundsException if field is outside
853 * the valid range. The value of field must be >= 0 and
854 * <= <code>FIELD_COUNT</code>.
856 public final void clear(int field
)
860 1, 1970, JANUARY
, 1, 1, 1, 1, THURSDAY
, 1, AM
, 0, 0, 0,
861 0, 0, zone
.getRawOffset(), 0
864 areFieldsSet
= false;
865 isSet
[field
] = false;
866 fields
[field
] = tempFields
[field
];
870 * Determines if the specified field has a valid value.
871 * @return true if the specified field has a value.
872 * @throws ArrayIndexOutOfBoundsException if the field is outside
873 * the valid range. The value of field must be >= 0 and
874 * <= <code>FIELD_COUNT</code>.
876 public final boolean isSet(int field
)
882 * Fills any unset fields in the time field list
884 protected void complete()
893 * Compares the given calendar with this.
894 * @param o the object to that we should compare.
895 * @return true, if the given object is a calendar, that represents
896 * the same time (but doesn't necessary have the same fields).
898 public boolean equals(Object o
)
900 if (! (o
instanceof Calendar
))
902 Calendar cal
= (Calendar
) o
;
903 if (getTimeInMillis() == ((Calendar
) o
).getTimeInMillis()
904 && cal
.getFirstDayOfWeek() == getFirstDayOfWeek()
905 && cal
.isLenient() == isLenient()
906 && cal
.getMinimalDaysInFirstWeek() == getMinimalDaysInFirstWeek())
908 TimeZone self
= getTimeZone();
909 TimeZone oth
= cal
.getTimeZone();
910 return self
== null ? oth
== null : self
.equals(oth
);
916 * Returns a hash code for this calendar.
917 * @return a hash code, which fullfits the general contract of
918 * <code>hashCode()</code>
920 public int hashCode()
922 long time
= getTimeInMillis();
923 int val
= (int) ((time
& 0xffffffffL
) ^
(time
>> 32));
924 val
+= (getFirstDayOfWeek() + (isLenient() ?
1230 : 1237)
925 + getMinimalDaysInFirstWeek());
926 TimeZone self
= getTimeZone();
928 val ^
= self
.hashCode();
933 * Compares the given calendar with this.
934 * @param o the object to that we should compare.
935 * @return true, if the given object is a calendar, and this calendar
936 * represents a smaller time than the calendar o.
937 * @exception ClassCastException if o is not an calendar.
938 * @since JDK1.2 you don't need to override this method
940 public boolean before(Object o
)
942 return getTimeInMillis() < ((Calendar
) o
).getTimeInMillis();
946 * Compares the given calendar with this.
947 * @param o the object to that we should compare.
948 * @return true, if the given object is a calendar, and this calendar
949 * represents a bigger time than the calendar o.
950 * @exception ClassCastException if o is not an calendar.
951 * @since JDK1.2 you don't need to override this method
953 public boolean after(Object o
)
955 return getTimeInMillis() > ((Calendar
) o
).getTimeInMillis();
959 * Adds the specified amount of time to the given time field. The
960 * amount may be negative to subtract the time. If the field overflows
961 * it does what you expect: Jan, 25 + 10 Days is Feb, 4.
962 * @param field the time field. One of the time field constants.
963 * @param amount the amount of time.
964 * @throws ArrayIndexOutOfBoundsException if the field is outside
965 * the valid range. The value of field must be >= 0 and
966 * <= <code>FIELD_COUNT</code>.
968 public abstract void add(int field
, int amount
);
971 * Rolls the specified time field up or down. This means add one
972 * to the specified field, but don't change the other fields. If
973 * the maximum for this field is reached, start over with the
974 * minimum value. <br>
976 * <strong>Note:</strong> There may be situation, where the other
977 * fields must be changed, e.g rolling the month on May, 31.
978 * The date June, 31 is automatically converted to July, 1.
979 * @param field the time field. One of the time field constants.
980 * @param up the direction, true for up, false for down.
981 * @throws ArrayIndexOutOfBoundsException if the field is outside
982 * the valid range. The value of field must be >= 0 and
983 * <= <code>FIELD_COUNT</code>.
985 public abstract void roll(int field
, boolean up
);
988 * Rolls up or down the specified time field by the given amount.
989 * A negative amount rolls down. The default implementation is
990 * call <code>roll(int, boolean)</code> for the specified amount.
992 * Subclasses should override this method to do more intuitiv things.
994 * @param field the time field. One of the time field constants.
995 * @param amount the amount to roll by, positive for rolling up,
996 * negative for rolling down.
997 * @throws ArrayIndexOutOfBoundsException if the field is outside
998 * the valid range. The value of field must be >= 0 and
999 * <= <code>FIELD_COUNT</code>.
1002 public void roll(int field
, int amount
)
1017 * Sets the time zone to the specified value.
1018 * @param zone the new time zone
1020 public void setTimeZone(TimeZone zone
)
1026 * Gets the time zone of this calendar
1027 * @return the current time zone.
1029 public TimeZone
getTimeZone()
1035 * Specifies if the date/time interpretation should be lenient.
1036 * If the flag is set, a date such as "February 30, 1996" will be
1037 * treated as the 29th day after the February 1. If this flag
1038 * is false, such dates will cause an exception.
1039 * @param lenient true, if the date should be interpreted linient,
1040 * false if it should be interpreted strict.
1042 public void setLenient(boolean lenient
)
1044 this.lenient
= lenient
;
1048 * Tells if the date/time interpretation is lenient.
1049 * @return true, if the date should be interpreted linient,
1050 * false if it should be interpreted strict.
1052 public boolean isLenient()
1058 * Sets what the first day of week is. This is used for
1059 * WEEK_OF_MONTH and WEEK_OF_YEAR fields.
1060 * @param value the first day of week. One of SUNDAY to SATURDAY.
1062 public void setFirstDayOfWeek(int value
)
1064 firstDayOfWeek
= value
;
1068 * Gets what the first day of week is. This is used for
1069 * WEEK_OF_MONTH and WEEK_OF_YEAR fields.
1070 * @return the first day of week. One of SUNDAY to SATURDAY.
1072 public int getFirstDayOfWeek()
1074 return firstDayOfWeek
;
1078 * Sets how many days are required in the first week of the year.
1079 * If the first day of the year should be the first week you should
1080 * set this value to 1. If the first week must be a full week, set
1082 * @param value the minimal days required in the first week.
1084 public void setMinimalDaysInFirstWeek(int value
)
1086 minimalDaysInFirstWeek
= value
;
1090 * Gets how many days are required in the first week of the year.
1091 * @return the minimal days required in the first week.
1092 * @see #setMinimalDaysInFirstWeek
1094 public int getMinimalDaysInFirstWeek()
1096 return minimalDaysInFirstWeek
;
1100 * Gets the smallest value that is allowed for the specified field.
1101 * @param field the time field. One of the time field constants.
1102 * @return the smallest value.
1104 public abstract int getMinimum(int field
);
1107 * Gets the biggest value that is allowed for the specified field.
1108 * @param field the time field. One of the time field constants.
1109 * @return the biggest value.
1111 public abstract int getMaximum(int field
);
1114 * Gets the greatest minimum value that is allowed for the specified field.
1115 * @param field the time field. One of the time field constants.
1116 * @return the greatest minimum value.
1118 public abstract int getGreatestMinimum(int field
);
1121 * Gets the smallest maximum value that is allowed for the
1122 * specified field. For example this is 28 for DAY_OF_MONTH.
1123 * @param field the time field. One of the time field constants.
1124 * @return the least maximum value.
1126 public abstract int getLeastMaximum(int field
);
1129 * Gets the actual minimum value that is allowed for the specified field.
1130 * This value is dependent on the values of the other fields.
1131 * @param field the time field. One of the time field constants.
1132 * @return the actual minimum value.
1133 * @throws ArrayIndexOutOfBoundsException if the field is outside
1134 * the valid range. The value of field must be >= 0 and
1135 * <= <code>FIELD_COUNT</code>.
1138 public int getActualMinimum(int field
)
1140 Calendar tmp
= (Calendar
) clone(); // To avoid restoring state
1141 int min
= tmp
.getGreatestMinimum(field
);
1142 int end
= tmp
.getMinimum(field
);
1143 tmp
.set(field
, min
);
1144 for (; min
> end
; min
--)
1146 tmp
.add(field
, -1); // Try to get smaller
1147 if (tmp
.get(field
) != min
- 1)
1148 break; // Done if not successful
1154 * Gets the actual maximum value that is allowed for the specified field.
1155 * This value is dependent on the values of the other fields.
1156 * @param field the time field. One of the time field constants.
1157 * @return the actual maximum value.
1158 * @throws ArrayIndexOutOfBoundsException if the field is outside
1159 * the valid range. The value of field must be >= 0 and
1160 * <= <code>FIELD_COUNT</code>.
1163 public int getActualMaximum(int field
)
1165 Calendar tmp
= (Calendar
) clone(); // To avoid restoring state
1166 int max
= tmp
.getLeastMaximum(field
);
1167 int end
= tmp
.getMaximum(field
);
1168 tmp
.set(field
, max
);
1169 for (; max
< end
; max
++)
1172 if (tmp
.get(field
) != max
+ 1)
1179 * Return a clone of this object.
1181 public Object
clone()
1185 Calendar cal
= (Calendar
) super.clone();
1186 cal
.fields
= (int[]) fields
.clone();
1187 cal
.isSet
= (boolean[]) isSet
.clone();
1190 catch (CloneNotSupportedException ex
)
1196 private static final String
[] fieldNames
=
1198 ",ERA=", ",YEAR=", ",MONTH=",
1202 ",DAY_OF_YEAR=", ",DAY_OF_WEEK=",
1203 ",DAY_OF_WEEK_IN_MONTH=",
1204 ",AM_PM=", ",HOUR=",
1205 ",HOUR_OF_DAY=", ",MINUTE=",
1206 ",SECOND=", ",MILLISECOND=",
1207 ",ZONE_OFFSET=", ",DST_OFFSET="
1211 * Returns a string representation of this object. It is mainly
1212 * for debugging purposes and its content is implementation
1215 public String
toString()
1217 StringBuffer sb
= new StringBuffer();
1218 sb
.append(getClass().getName()).append('[');
1224 sb
.append(",zone=" + zone
);
1225 sb
.append(",areFieldsSet=" + areFieldsSet
);
1226 for (int i
= 0; i
< FIELD_COUNT
; i
++)
1228 sb
.append(fieldNames
[i
]);
1230 sb
.append(fields
[i
]);
1234 sb
.append(",lenient=").append(lenient
);
1235 sb
.append(",firstDayOfWeek=").append(firstDayOfWeek
);
1236 sb
.append(",minimalDaysInFirstWeek=").append(minimalDaysInFirstWeek
);
1238 return sb
.toString();
1242 * Saves the state of the object to the stream. Ideally we would
1243 * only write the time field, but we need to be compatible with
1244 * earlier versions. <br>
1246 * This doesn't write the JDK1.1 field nextStamp to the stream, as
1247 * I don't know what it is good for, and because the documentation
1248 * says, that it could be omitted. */
1249 private void writeObject(ObjectOutputStream stream
) throws IOException
1253 stream
.defaultWriteObject();
1257 * Reads the object back from stream (deserialization).
1259 private void readObject(ObjectInputStream stream
)
1260 throws IOException
, ClassNotFoundException
1262 stream
.defaultReadObject();
1266 if (serialVersionOnStream
> 1)
1268 // This is my interpretation of the serial number:
1269 // Sun wants to remove all fields from the stream someday
1270 // and will then increase the serialVersion number again.
1271 // We prepare to be compatible.
1272 fields
= new int[FIELD_COUNT
];
1273 isSet
= new boolean[FIELD_COUNT
];
1274 areFieldsSet
= false;