/* * Copyright (c) 1996, 2010, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /* * (C) Copyright Taligent, Inc. 1996 - All Rights Reserved * (C) Copyright IBM Corp. 1996 - All Rights Reserved * * The original version of this source code and documentation is copyrighted * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These * materials are provided under terms of a License Agreement between Taligent * and Sun. This technology is protected by multiple US and International * patents. This notice and attribution to Taligent may not be removed. * Taligent is a registered trademark of Taligent, Inc. * */ package java.text; import java.io.InvalidObjectException; import java.text.spi.DateFormatProvider; import java.util.Calendar; import java.util.Date; import java.util.GregorianCalendar; import java.util.HashMap; import java.util.Locale; import java.util.Map; import java.util.MissingResourceException; import java.util.ResourceBundle; import java.util.TimeZone; import java.util.spi.LocaleServiceProvider; import sun.util.LocaleServiceProviderPool; /** * {@code DateFormat} is an abstract class for date/time formatting subclasses which * formats and parses dates or time in a language-independent manner. * The date/time formatting subclass, such as {@link SimpleDateFormat}, allows for * formatting (i.e., date -> text), parsing (text -> date), and * normalization. The date is represented as a Date object or * as the milliseconds since January 1, 1970, 00:00:00 GMT. * *

{@code DateFormat} provides many class methods for obtaining default date/time * formatters based on the default or a given locale and a number of formatting * styles. The formatting styles include {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, and {@link #SHORT}. More * detail and examples of using these styles are provided in the method * descriptions. * *

{@code DateFormat} helps you to format and parse dates for any locale. * Your code can be completely independent of the locale conventions for * months, days of the week, or even the calendar format: lunar vs. solar. * *

To format a date for the current Locale, use one of the * static factory methods: *

 *  myString = DateFormat.getDateInstance().format(myDate);
 * 
*

If you are formatting multiple dates, it is * more efficient to get the format and use it multiple times so that * the system doesn't have to fetch the information about the local * language and country conventions multiple times. *

 *  DateFormat df = DateFormat.getDateInstance();
 *  for (int i = 0; i < myDate.length; ++i) {
 *    output.println(df.format(myDate[i]) + "; ");
 *  }
 * 
*

To format a date for a different Locale, specify it in the * call to {@link #getDateInstance(int, Locale) getDateInstance()}. *

 *  DateFormat df = DateFormat.getDateInstance(DateFormat.LONG, Locale.FRANCE);
 * 
*

You can use a DateFormat to parse also. *

 *  myDate = df.parse(myString);
 * 
*

Use {@code getDateInstance} to get the normal date format for that country. * There are other static factory methods available. * Use {@code getTimeInstance} to get the time format for that country. * Use {@code getDateTimeInstance} to get a date and time format. You can pass in * different options to these factory methods to control the length of the * result; from {@link #SHORT} to {@link #MEDIUM} to {@link #LONG} to {@link #FULL}. The exact result depends * on the locale, but generally: *

* *

You can also set the time zone on the format if you wish. * If you want even more control over the format or parsing, * (or want to give your users more control), * you can try casting the {@code DateFormat} you get from the factory methods * to a {@link SimpleDateFormat}. This will work for the majority * of countries; just remember to put it in a {@code try} block in case you * encounter an unusual one. * *

You can also use forms of the parse and format methods with * {@link ParsePosition} and {@link FieldPosition} to * allow you to *

* *

Synchronization

* *

* Date formats are not synchronized. * It is recommended to create separate format instances for each thread. * If multiple threads access a format concurrently, it must be synchronized * externally. * * @see Format * @see NumberFormat * @see SimpleDateFormat * @see java.util.Calendar * @see java.util.GregorianCalendar * @see java.util.TimeZone * @author Mark Davis, Chen-Lieh Huang, Alan Liu */ public abstract class DateFormat extends Format { /** * The {@link Calendar} instance used for calculating the date-time fields * and the instant of time. This field is used for both formatting and * parsing. * *

Subclasses should initialize this field to a {@link Calendar} * appropriate for the {@link Locale} associated with this * DateFormat. * @serial */ protected Calendar calendar; /** * The number formatter that DateFormat uses to format numbers * in dates and times. Subclasses should initialize this to a number format * appropriate for the locale associated with this DateFormat. * @serial */ protected NumberFormat numberFormat; /** * Useful constant for ERA field alignment. * Used in FieldPosition of date/time formatting. */ public final static int ERA_FIELD = 0; /** * Useful constant for YEAR field alignment. * Used in FieldPosition of date/time formatting. */ public final static int YEAR_FIELD = 1; /** * Useful constant for MONTH field alignment. * Used in FieldPosition of date/time formatting. */ public final static int MONTH_FIELD = 2; /** * Useful constant for DATE field alignment. * Used in FieldPosition of date/time formatting. */ public final static int DATE_FIELD = 3; /** * Useful constant for one-based HOUR_OF_DAY field alignment. * Used in FieldPosition of date/time formatting. * HOUR_OF_DAY1_FIELD is used for the one-based 24-hour clock. * For example, 23:59 + 01:00 results in 24:59. */ public final static int HOUR_OF_DAY1_FIELD = 4; /** * Useful constant for zero-based HOUR_OF_DAY field alignment. * Used in FieldPosition of date/time formatting. * HOUR_OF_DAY0_FIELD is used for the zero-based 24-hour clock. * For example, 23:59 + 01:00 results in 00:59. */ public final static int HOUR_OF_DAY0_FIELD = 5; /** * Useful constant for MINUTE field alignment. * Used in FieldPosition of date/time formatting. */ public final static int MINUTE_FIELD = 6; /** * Useful constant for SECOND field alignment. * Used in FieldPosition of date/time formatting. */ public final static int SECOND_FIELD = 7; /** * Useful constant for MILLISECOND field alignment. * Used in FieldPosition of date/time formatting. */ public final static int MILLISECOND_FIELD = 8; /** * Useful constant for DAY_OF_WEEK field alignment. * Used in FieldPosition of date/time formatting. */ public final static int DAY_OF_WEEK_FIELD = 9; /** * Useful constant for DAY_OF_YEAR field alignment. * Used in FieldPosition of date/time formatting. */ public final static int DAY_OF_YEAR_FIELD = 10; /** * Useful constant for DAY_OF_WEEK_IN_MONTH field alignment. * Used in FieldPosition of date/time formatting. */ public final static int DAY_OF_WEEK_IN_MONTH_FIELD = 11; /** * Useful constant for WEEK_OF_YEAR field alignment. * Used in FieldPosition of date/time formatting. */ public final static int WEEK_OF_YEAR_FIELD = 12; /** * Useful constant for WEEK_OF_MONTH field alignment. * Used in FieldPosition of date/time formatting. */ public final static int WEEK_OF_MONTH_FIELD = 13; /** * Useful constant for AM_PM field alignment. * Used in FieldPosition of date/time formatting. */ public final static int AM_PM_FIELD = 14; /** * Useful constant for one-based HOUR field alignment. * Used in FieldPosition of date/time formatting. * HOUR1_FIELD is used for the one-based 12-hour clock. * For example, 11:30 PM + 1 hour results in 12:30 AM. */ public final static int HOUR1_FIELD = 15; /** * Useful constant for zero-based HOUR field alignment. * Used in FieldPosition of date/time formatting. * HOUR0_FIELD is used for the zero-based 12-hour clock. * For example, 11:30 PM + 1 hour results in 00:30 AM. */ public final static int HOUR0_FIELD = 16; /** * Useful constant for TIMEZONE field alignment. * Used in FieldPosition of date/time formatting. */ public final static int TIMEZONE_FIELD = 17; // Proclaim serial compatibility with 1.1 FCS private static final long serialVersionUID = 7218322306649953788L; /** * Overrides Format. * Formats a time object into a time string. Examples of time objects * are a time value expressed in milliseconds and a Date object. * @param obj must be a Number or a Date. * @param toAppendTo the string buffer for the returning time string. * @return the string buffer passed in as toAppendTo, with formatted text appended. * @param fieldPosition keeps track of the position of the field * within the returned string. * On input: an alignment field, * if desired. On output: the offsets of the alignment field. For * example, given a time text "1996.07.10 AD at 15:08:56 PDT", * if the given fieldPosition is DateFormat.YEAR_FIELD, the * begin index and end index of fieldPosition will be set to * 0 and 4, respectively. * Notice that if the same time field appears * more than once in a pattern, the fieldPosition will be set for the first * occurrence of that time field. For instance, formatting a Date to * the time string "1 PM PDT (Pacific Daylight Time)" using the pattern * "h a z (zzzz)" and the alignment field DateFormat.TIMEZONE_FIELD, * the begin index and end index of fieldPosition will be set to * 5 and 8, respectively, for the first occurrence of the timezone * pattern character 'z'. * @see java.text.Format */ public final StringBuffer format(Object obj, StringBuffer toAppendTo, FieldPosition fieldPosition) { if (obj instanceof Date) return format( (Date)obj, toAppendTo, fieldPosition ); else if (obj instanceof Number) return format( new Date(((Number)obj).longValue()), toAppendTo, fieldPosition ); else throw new IllegalArgumentException("Cannot format given Object as a Date"); } /** * Formats a Date into a date/time string. * @param date a Date to be formatted into a date/time string. * @param toAppendTo the string buffer for the returning date/time string. * @param fieldPosition keeps track of the position of the field * within the returned string. * On input: an alignment field, * if desired. On output: the offsets of the alignment field. For * example, given a time text "1996.07.10 AD at 15:08:56 PDT", * if the given fieldPosition is DateFormat.YEAR_FIELD, the * begin index and end index of fieldPosition will be set to * 0 and 4, respectively. * Notice that if the same time field appears * more than once in a pattern, the fieldPosition will be set for the first * occurrence of that time field. For instance, formatting a Date to * the time string "1 PM PDT (Pacific Daylight Time)" using the pattern * "h a z (zzzz)" and the alignment field DateFormat.TIMEZONE_FIELD, * the begin index and end index of fieldPosition will be set to * 5 and 8, respectively, for the first occurrence of the timezone * pattern character 'z'. * @return the string buffer passed in as toAppendTo, with formatted text appended. */ public abstract StringBuffer format(Date date, StringBuffer toAppendTo, FieldPosition fieldPosition); /** * Formats a Date into a date/time string. * @param date the time value to be formatted into a time string. * @return the formatted time string. */ public final String format(Date date) { return format(date, new StringBuffer(), DontCareFieldPosition.INSTANCE).toString(); } /** * Parses text from the beginning of the given string to produce a date. * The method may not use the entire text of the given string. *

* See the {@link #parse(String, ParsePosition)} method for more information * on date parsing. * * @param source A String whose beginning should be parsed. * @return A Date parsed from the string. * @exception ParseException if the beginning of the specified string * cannot be parsed. */ public Date parse(String source) throws ParseException { ParsePosition pos = new ParsePosition(0); Date result = parse(source, pos); if (pos.index == 0) throw new ParseException("Unparseable date: \"" + source + "\"" , pos.errorIndex); return result; } /** * Parse a date/time string according to the given parse position. For * example, a time text {@code "07/10/96 4:5 PM, PDT"} will be parsed into a {@code Date} * that is equivalent to {@code Date(837039900000L)}. * *

By default, parsing is lenient: If the input is not in the form used * by this object's format method but can still be parsed as a date, then * the parse succeeds. Clients may insist on strict adherence to the * format by calling {@link #setLenient(boolean) setLenient(false)}. * *

This parsing operation uses the {@link #calendar} to produce * a {@code Date}. As a result, the {@code calendar}'s date-time * fields and the {@code TimeZone} value may have been * overwritten, depending on subclass implementations. Any {@code * TimeZone} value that has previously been set by a call to * {@link #setTimeZone(java.util.TimeZone) setTimeZone} may need * to be restored for further operations. * * @param source The date/time string to be parsed * * @param pos On input, the position at which to start parsing; on * output, the position at which parsing terminated, or the * start position if the parse failed. * * @return A {@code Date}, or {@code null} if the input could not be parsed */ public abstract Date parse(String source, ParsePosition pos); /** * Parses text from a string to produce a Date. *

* The method attempts to parse text starting at the index given by * pos. * If parsing succeeds, then the index of pos is updated * to the index after the last character used (parsing does not necessarily * use all characters up to the end of the string), and the parsed * date is returned. The updated pos can be used to * indicate the starting point for the next call to this method. * If an error occurs, then the index of pos is not * changed, the error index of pos is set to the index of * the character where the error occurred, and null is returned. *

* See the {@link #parse(String, ParsePosition)} method for more information * on date parsing. * * @param source A String, part of which should be parsed. * @param pos A ParsePosition object with index and error * index information as described above. * @return A Date parsed from the string. In case of * error, returns null. * @exception NullPointerException if pos is null. */ public Object parseObject(String source, ParsePosition pos) { return parse(source, pos); } /** * Constant for full style pattern. */ public static final int FULL = 0; /** * Constant for long style pattern. */ public static final int LONG = 1; /** * Constant for medium style pattern. */ public static final int MEDIUM = 2; /** * Constant for short style pattern. */ public static final int SHORT = 3; /** * Constant for default style pattern. Its value is MEDIUM. */ public static final int DEFAULT = MEDIUM; /** * Gets the time formatter with the default formatting style * for the default locale. * @return a time formatter. */ public final static DateFormat getTimeInstance() { return get(DEFAULT, 0, 1, Locale.getDefault(Locale.Category.FORMAT)); } /** * Gets the time formatter with the given formatting style * for the default locale. * @param style the given formatting style. For example, * SHORT for "h:mm a" in the US locale. * @return a time formatter. */ public final static DateFormat getTimeInstance(int style) { return get(style, 0, 1, Locale.getDefault(Locale.Category.FORMAT)); } /** * Gets the time formatter with the given formatting style * for the given locale. * @param style the given formatting style. For example, * SHORT for "h:mm a" in the US locale. * @param aLocale the given locale. * @return a time formatter. */ public final static DateFormat getTimeInstance(int style, Locale aLocale) { return get(style, 0, 1, aLocale); } /** * Gets the date formatter with the default formatting style * for the default locale. * @return a date formatter. */ public final static DateFormat getDateInstance() { return get(0, DEFAULT, 2, Locale.getDefault(Locale.Category.FORMAT)); } /** * Gets the date formatter with the given formatting style * for the default locale. * @param style the given formatting style. For example, * SHORT for "M/d/yy" in the US locale. * @return a date formatter. */ public final static DateFormat getDateInstance(int style) { return get(0, style, 2, Locale.getDefault(Locale.Category.FORMAT)); } /** * Gets the date formatter with the given formatting style * for the given locale. * @param style the given formatting style. For example, * SHORT for "M/d/yy" in the US locale. * @param aLocale the given locale. * @return a date formatter. */ public final static DateFormat getDateInstance(int style, Locale aLocale) { return get(0, style, 2, aLocale); } /** * Gets the date/time formatter with the default formatting style * for the default locale. * @return a date/time formatter. */ public final static DateFormat getDateTimeInstance() { return get(DEFAULT, DEFAULT, 3, Locale.getDefault(Locale.Category.FORMAT)); } /** * Gets the date/time formatter with the given date and time * formatting styles for the default locale. * @param dateStyle the given date formatting style. For example, * SHORT for "M/d/yy" in the US locale. * @param timeStyle the given time formatting style. For example, * SHORT for "h:mm a" in the US locale. * @return a date/time formatter. */ public final static DateFormat getDateTimeInstance(int dateStyle, int timeStyle) { return get(timeStyle, dateStyle, 3, Locale.getDefault(Locale.Category.FORMAT)); } /** * Gets the date/time formatter with the given formatting styles * for the given locale. * @param dateStyle the given date formatting style. * @param timeStyle the given time formatting style. * @param aLocale the given locale. * @return a date/time formatter. */ public final static DateFormat getDateTimeInstance(int dateStyle, int timeStyle, Locale aLocale) { return get(timeStyle, dateStyle, 3, aLocale); } /** * Get a default date/time formatter that uses the SHORT style for both the * date and the time. */ public final static DateFormat getInstance() { return getDateTimeInstance(SHORT, SHORT); } /** * Returns an array of all locales for which the * get*Instance methods of this class can return * localized instances. * The returned array represents the union of locales supported by the Java * runtime and by installed * {@link java.text.spi.DateFormatProvider DateFormatProvider} implementations. * It must contain at least a Locale instance equal to * {@link java.util.Locale#US Locale.US}. * * @return An array of locales for which localized * DateFormat instances are available. */ public static Locale[] getAvailableLocales() { LocaleServiceProviderPool pool = LocaleServiceProviderPool.getPool(DateFormatProvider.class); return pool.getAvailableLocales(); } /** * Set the calendar to be used by this date format. Initially, the default * calendar for the specified or default locale is used. * *

Any {@link java.util.TimeZone TimeZone} and {@linkplain * #isLenient() leniency} values that have previously been set are * overwritten by {@code newCalendar}'s values. * * @param newCalendar the new {@code Calendar} to be used by the date format */ public void setCalendar(Calendar newCalendar) { this.calendar = newCalendar; } /** * Gets the calendar associated with this date/time formatter. * * @return the calendar associated with this date/time formatter. */ public Calendar getCalendar() { return calendar; } /** * Allows you to set the number formatter. * @param newNumberFormat the given new NumberFormat. */ public void setNumberFormat(NumberFormat newNumberFormat) { this.numberFormat = newNumberFormat; } /** * Gets the number formatter which this date/time formatter uses to * format and parse a time. * @return the number formatter which this date/time formatter uses. */ public NumberFormat getNumberFormat() { return numberFormat; } /** * Sets the time zone for the calendar of this {@code DateFormat} object. * This method is equivalent to the following call. *

     *  getCalendar().setTimeZone(zone)
     * 
* *

The {@code TimeZone} set by this method is overwritten by a * {@link #setCalendar(java.util.Calendar) setCalendar} call. * *

The {@code TimeZone} set by this method may be overwritten as * a result of a call to the parse method. * * @param zone the given new time zone. */ public void setTimeZone(TimeZone zone) { calendar.setTimeZone(zone); } /** * Gets the time zone. * This method is equivalent to the following call. *

     *  getCalendar().getTimeZone()
     * 
* * @return the time zone associated with the calendar of DateFormat. */ public TimeZone getTimeZone() { return calendar.getTimeZone(); } /** * Specify whether or not date/time parsing is to be lenient. With * lenient parsing, the parser may use heuristics to interpret inputs that * do not precisely match this object's format. With strict parsing, * inputs must match this object's format. * *

This method is equivalent to the following call. *

     *  getCalendar().setLenient(lenient)
     * 
* *

This leniency value is overwritten by a call to {@link * #setCalendar(java.util.Calendar) setCalendar()}. * * @param lenient when {@code true}, parsing is lenient * @see java.util.Calendar#setLenient(boolean) */ public void setLenient(boolean lenient) { calendar.setLenient(lenient); } /** * Tell whether date/time parsing is to be lenient. * This method is equivalent to the following call. *

     *  getCalendar().isLenient()
     * 
* * @return {@code true} if the {@link #calendar} is lenient; * {@code false} otherwise. * @see java.util.Calendar#isLenient() */ public boolean isLenient() { return calendar.isLenient(); } /** * Overrides hashCode */ public int hashCode() { return numberFormat.hashCode(); // just enough fields for a reasonable distribution } /** * Overrides equals */ public boolean equals(Object obj) { if (this == obj) return true; if (obj == null || getClass() != obj.getClass()) return false; DateFormat other = (DateFormat) obj; return (// calendar.equivalentTo(other.calendar) // THIS API DOESN'T EXIST YET! calendar.getFirstDayOfWeek() == other.calendar.getFirstDayOfWeek() && calendar.getMinimalDaysInFirstWeek() == other.calendar.getMinimalDaysInFirstWeek() && calendar.isLenient() == other.calendar.isLenient() && calendar.getTimeZone().equals(other.calendar.getTimeZone()) && numberFormat.equals(other.numberFormat)); } /** * Overrides Cloneable */ public Object clone() { DateFormat other = (DateFormat) super.clone(); other.calendar = (Calendar) calendar.clone(); other.numberFormat = (NumberFormat) numberFormat.clone(); return other; } /** * Creates a DateFormat with the given time and/or date style in the given * locale. * @param timeStyle a value from 0 to 3 indicating the time format, * ignored if flags is 2 * @param dateStyle a value from 0 to 3 indicating the time format, * ignored if flags is 1 * @param flags either 1 for a time format, 2 for a date format, * or 3 for a date/time format * @param loc the locale for the format */ private static DateFormat get(int timeStyle, int dateStyle, int flags, Locale loc) { if ((flags & 1) != 0) { if (timeStyle < 0 || timeStyle > 3) { throw new IllegalArgumentException("Illegal time style " + timeStyle); } } else { timeStyle = -1; } if ((flags & 2) != 0) { if (dateStyle < 0 || dateStyle > 3) { throw new IllegalArgumentException("Illegal date style " + dateStyle); } } else { dateStyle = -1; } try { // Check whether a provider can provide an implementation that's closer // to the requested locale than what the Java runtime itself can provide. LocaleServiceProviderPool pool = LocaleServiceProviderPool.getPool(DateFormatProvider.class); if (pool.hasProviders()) { DateFormat providersInstance = pool.getLocalizedObject( DateFormatGetter.INSTANCE, loc, timeStyle, dateStyle, flags); if (providersInstance != null) { return providersInstance; } } return new SimpleDateFormat(timeStyle, dateStyle, loc); } catch (MissingResourceException e) { return new SimpleDateFormat("M/d/yy h:mm a"); } } /** * Create a new date format. */ protected DateFormat() {} /** * Defines constants that are used as attribute keys in the * AttributedCharacterIterator returned * from DateFormat.formatToCharacterIterator and as * field identifiers in FieldPosition. *

* The class also provides two methods to map * between its constants and the corresponding Calendar constants. * * @since 1.4 * @see java.util.Calendar */ public static class Field extends Format.Field { // Proclaim serial compatibility with 1.4 FCS private static final long serialVersionUID = 7441350119349544720L; // table of all instances in this class, used by readResolve private static final Map instanceMap = new HashMap(18); // Maps from Calendar constant (such as Calendar.ERA) to Field // constant (such as Field.ERA). private static final Field[] calendarToFieldMapping = new Field[Calendar.FIELD_COUNT]; /** Calendar field. */ private int calendarField; /** * Returns the Field constant that corresponds to * the Calendar constant calendarField. * If there is no direct mapping between the Calendar * constant and a Field, null is returned. * * @throws IllegalArgumentException if calendarField is * not the value of a Calendar field constant. * @param calendarField Calendar field constant * @return Field instance representing calendarField. * @see java.util.Calendar */ public static Field ofCalendarField(int calendarField) { if (calendarField < 0 || calendarField >= calendarToFieldMapping.length) { throw new IllegalArgumentException("Unknown Calendar constant " + calendarField); } return calendarToFieldMapping[calendarField]; } /** * Creates a Field. * * @param name the name of the Field * @param calendarField the Calendar constant this * Field corresponds to; any value, even one * outside the range of legal Calendar values may * be used, but -1 should be used for values * that don't correspond to legal Calendar values */ protected Field(String name, int calendarField) { super(name); this.calendarField = calendarField; if (this.getClass() == DateFormat.Field.class) { instanceMap.put(name, this); if (calendarField >= 0) { // assert(calendarField < Calendar.FIELD_COUNT); calendarToFieldMapping[calendarField] = this; } } } /** * Returns the Calendar field associated with this * attribute. For example, if this represents the hours field of * a Calendar, this would return * Calendar.HOUR. If there is no corresponding * Calendar constant, this will return -1. * * @return Calendar constant for this field * @see java.util.Calendar */ public int getCalendarField() { return calendarField; } /** * Resolves instances being deserialized to the predefined constants. * * @throws InvalidObjectException if the constant could not be * resolved. * @return resolved DateFormat.Field constant */ protected Object readResolve() throws InvalidObjectException { if (this.getClass() != DateFormat.Field.class) { throw new InvalidObjectException("subclass didn't correctly implement readResolve"); } Object instance = instanceMap.get(getName()); if (instance != null) { return instance; } else { throw new InvalidObjectException("unknown attribute name"); } } // // The constants // /** * Constant identifying the era field. */ public final static Field ERA = new Field("era", Calendar.ERA); /** * Constant identifying the year field. */ public final static Field YEAR = new Field("year", Calendar.YEAR); /** * Constant identifying the month field. */ public final static Field MONTH = new Field("month", Calendar.MONTH); /** * Constant identifying the day of month field. */ public final static Field DAY_OF_MONTH = new Field("day of month", Calendar.DAY_OF_MONTH); /** * Constant identifying the hour of day field, where the legal values * are 1 to 24. */ public final static Field HOUR_OF_DAY1 = new Field("hour of day 1",-1); /** * Constant identifying the hour of day field, where the legal values * are 0 to 23. */ public final static Field HOUR_OF_DAY0 = new Field("hour of day", Calendar.HOUR_OF_DAY); /** * Constant identifying the minute field. */ public final static Field MINUTE =new Field("minute", Calendar.MINUTE); /** * Constant identifying the second field. */ public final static Field SECOND =new Field("second", Calendar.SECOND); /** * Constant identifying the millisecond field. */ public final static Field MILLISECOND = new Field("millisecond", Calendar.MILLISECOND); /** * Constant identifying the day of week field. */ public final static Field DAY_OF_WEEK = new Field("day of week", Calendar.DAY_OF_WEEK); /** * Constant identifying the day of year field. */ public final static Field DAY_OF_YEAR = new Field("day of year", Calendar.DAY_OF_YEAR); /** * Constant identifying the day of week field. */ public final static Field DAY_OF_WEEK_IN_MONTH = new Field("day of week in month", Calendar.DAY_OF_WEEK_IN_MONTH); /** * Constant identifying the week of year field. */ public final static Field WEEK_OF_YEAR = new Field("week of year", Calendar.WEEK_OF_YEAR); /** * Constant identifying the week of month field. */ public final static Field WEEK_OF_MONTH = new Field("week of month", Calendar.WEEK_OF_MONTH); /** * Constant identifying the time of day indicator * (e.g. "a.m." or "p.m.") field. */ public final static Field AM_PM = new Field("am pm", Calendar.AM_PM); /** * Constant identifying the hour field, where the legal values are * 1 to 12. */ public final static Field HOUR1 = new Field("hour 1", -1); /** * Constant identifying the hour field, where the legal values are * 0 to 11. */ public final static Field HOUR0 = new Field("hour", Calendar.HOUR); /** * Constant identifying the time zone field. */ public final static Field TIME_ZONE = new Field("time zone", -1); } /** * Obtains a DateFormat instance from a DateFormatProvider * implementation. */ private static class DateFormatGetter implements LocaleServiceProviderPool.LocalizedObjectGetter { private static final DateFormatGetter INSTANCE = new DateFormatGetter(); public DateFormat getObject(DateFormatProvider dateFormatProvider, Locale locale, String key, Object... params) { assert params.length == 3; int timeStyle = (Integer)params[0]; int dateStyle = (Integer)params[1]; int flags = (Integer)params[2]; switch (flags) { case 1: return dateFormatProvider.getTimeInstance(timeStyle, locale); case 2: return dateFormatProvider.getDateInstance(dateStyle, locale); case 3: return dateFormatProvider.getDateTimeInstance(dateStyle, timeStyle, locale); default: assert false : "should not happen"; } return null; } } }