1 /*

     2  * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 /*

    27  * (C) Copyright Taligent, Inc. 1996 - All Rights Reserved

    28  * (C) Copyright IBM Corp. 1996 - All Rights Reserved

    29  *

    30  *   The original version of this source code and documentation is copyrighted

    31  * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These

    32  * materials are provided under terms of a License Agreement between Taligent

    33  * and Sun. This technology is protected by multiple US and International

    34  * patents. This notice and attribution to Taligent may not be removed.

    35  *   Taligent is a registered trademark of Taligent, Inc.

    36  *

    37  */

    38 

    39 package java.text;

    40 

    41 import java.io.InvalidObjectException;

    42 import java.text.spi.DateFormatProvider;

    43 import java.util.Calendar;

    44 import java.util.Date;

    45 import java.util.GregorianCalendar;

    46 import java.util.HashMap;

    47 import java.util.Locale;

    48 import java.util.Map;

    49 import java.util.MissingResourceException;

    50 import java.util.ResourceBundle;

    51 import java.util.TimeZone;

    52 import java.util.spi.LocaleServiceProvider;

    53 import sun.util.locale.provider.LocaleProviderAdapter;

    54 import sun.util.locale.provider.LocaleServiceProviderPool;

    55 

    56 /**

    57  * {@code DateFormat} is an abstract class for date/time formatting subclasses which

    58  * formats and parses dates or time in a language-independent manner.

    59  * The date/time formatting subclass, such as {@link SimpleDateFormat}, allows for

    60  * formatting (i.e., date → text), parsing (text → date), and

    61  * normalization.  The date is represented as a <code>Date</code> object or

    62  * as the milliseconds since January 1, 1970, 00:00:00 GMT.

    63  *

    64  * <p>{@code DateFormat} provides many class methods for obtaining default date/time

    65  * formatters based on the default or a given locale and a number of formatting

    66  * styles. The formatting styles include {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, and {@link #SHORT}. More

    67  * detail and examples of using these styles are provided in the method

    68  * descriptions.

    69  *

    70  * <p>{@code DateFormat} helps you to format and parse dates for any locale.

    71  * Your code can be completely independent of the locale conventions for

    72  * months, days of the week, or even the calendar format: lunar vs. solar.

    73  *

    74  * <p>To format a date for the current Locale, use one of the

    75  * static factory methods:

    76  * <blockquote>

    77  * <pre>{@code

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

    79  * }</pre>

    80  * </blockquote>

    81  * <p>If you are formatting multiple dates, it is

    82  * more efficient to get the format and use it multiple times so that

    83  * the system doesn't have to fetch the information about the local

    84  * language and country conventions multiple times.

    85  * <blockquote>

    86  * <pre>{@code

    87  * DateFormat df = DateFormat.getDateInstance();

    88  * for (int i = 0; i < myDate.length; ++i) {

    89  *     output.println(df.format(myDate[i]) + "; ");

    90  * }

    91  * }</pre>

    92  * </blockquote>

    93  * <p>To format a date for a different Locale, specify it in the

    94  * call to {@link #getDateInstance(int, Locale) getDateInstance()}.

    95  * <blockquote>

    96  * <pre>{@code

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

    98  * }</pre>

    99  * </blockquote>

   100  * <p>You can use a DateFormat to parse also.

   101  * <blockquote>

   102  * <pre>{@code

   103  * myDate = df.parse(myString);

   104  * }</pre>

   105  * </blockquote>

   106  * <p>Use {@code getDateInstance} to get the normal date format for that country.

   107  * There are other static factory methods available.

   108  * Use {@code getTimeInstance} to get the time format for that country.

   109  * Use {@code getDateTimeInstance} to get a date and time format. You can pass in

   110  * different options to these factory methods to control the length of the

   111  * result; from {@link #SHORT} to {@link #MEDIUM} to {@link #LONG} to {@link #FULL}. The exact result depends

   112  * on the locale, but generally:

   113  * <ul><li>{@link #SHORT} is completely numeric, such as {@code 12.13.52} or {@code 3:30pm}

   114  * <li>{@link #MEDIUM} is longer, such as {@code Jan 12, 1952}

   115  * <li>{@link #LONG} is longer, such as {@code January 12, 1952} or {@code 3:30:32pm}

   116  * <li>{@link #FULL} is pretty completely specified, such as

   117  * {@code Tuesday, April 12, 1952 AD or 3:30:42pm PST}.

   118  * </ul>

   119  *

   120  * <p>You can also set the time zone on the format if you wish.

   121  * If you want even more control over the format or parsing,

   122  * (or want to give your users more control),

   123  * you can try casting the {@code DateFormat} you get from the factory methods

   124  * to a {@link SimpleDateFormat}. This will work for the majority

   125  * of countries; just remember to put it in a {@code try} block in case you

   126  * encounter an unusual one.

   127  *

   128  * <p>You can also use forms of the parse and format methods with

   129  * {@link ParsePosition} and {@link FieldPosition} to

   130  * allow you to

   131  * <ul><li>progressively parse through pieces of a string.

   132  * <li>align any particular field, or find out where it is for selection

   133  * on the screen.

   134  * </ul>

   135  *

   136  * <h3><a name="synchronization">Synchronization</a></h3>

   137  *

   138  * <p>

   139  * Date formats are not synchronized.

   140  * It is recommended to create separate format instances for each thread.

   141  * If multiple threads access a format concurrently, it must be synchronized

   142  * externally.

   143  *

   144  * @see          Format

   145  * @see          NumberFormat

   146  * @see          SimpleDateFormat

   147  * @see          java.util.Calendar

   148  * @see          java.util.GregorianCalendar

   149  * @see          java.util.TimeZone

   150  * @author       Mark Davis, Chen-Lieh Huang, Alan Liu

   151  */

   152 public abstract class DateFormat extends Format {

   153 

   154     /**

   155      * The {@link Calendar} instance used for calculating the date-time fields

   156      * and the instant of time. This field is used for both formatting and

   157      * parsing.

   158      *

   159      * <p>Subclasses should initialize this field to a {@link Calendar}

   160      * appropriate for the {@link Locale} associated with this

   161      * <code>DateFormat</code>.

   162      * @serial

   163      */

   164     protected Calendar calendar;

   165 

   166     /**

   167      * The number formatter that <code>DateFormat</code> uses to format numbers

   168      * in dates and times.  Subclasses should initialize this to a number format

   169      * appropriate for the locale associated with this <code>DateFormat</code>.

   170      * @serial

   171      */

   172     protected NumberFormat numberFormat;

   173 

   174     /**

   175      * Useful constant for ERA field alignment.

   176      * Used in FieldPosition of date/time formatting.

   177      */

   178     public final static int ERA_FIELD = 0;

   179     /**

   180      * Useful constant for YEAR field alignment.

   181      * Used in FieldPosition of date/time formatting.

   182      */

   183     public final static int YEAR_FIELD = 1;

   184     /**

   185      * Useful constant for MONTH field alignment.

   186      * Used in FieldPosition of date/time formatting.

   187      */

   188     public final static int MONTH_FIELD = 2;

   189     /**

   190      * Useful constant for DATE field alignment.

   191      * Used in FieldPosition of date/time formatting.

   192      */

   193     public final static int DATE_FIELD = 3;

   194     /**

   195      * Useful constant for one-based HOUR_OF_DAY field alignment.

   196      * Used in FieldPosition of date/time formatting.

   197      * HOUR_OF_DAY1_FIELD is used for the one-based 24-hour clock.

   198      * For example, 23:59 + 01:00 results in 24:59.

   199      */

   200     public final static int HOUR_OF_DAY1_FIELD = 4;

   201     /**

   202      * Useful constant for zero-based HOUR_OF_DAY field alignment.

   203      * Used in FieldPosition of date/time formatting.

   204      * HOUR_OF_DAY0_FIELD is used for the zero-based 24-hour clock.

   205      * For example, 23:59 + 01:00 results in 00:59.

   206      */

   207     public final static int HOUR_OF_DAY0_FIELD = 5;

   208     /**

   209      * Useful constant for MINUTE field alignment.

   210      * Used in FieldPosition of date/time formatting.

   211      */

   212     public final static int MINUTE_FIELD = 6;

   213     /**

   214      * Useful constant for SECOND field alignment.

   215      * Used in FieldPosition of date/time formatting.

   216      */

   217     public final static int SECOND_FIELD = 7;

   218     /**

   219      * Useful constant for MILLISECOND field alignment.

   220      * Used in FieldPosition of date/time formatting.

   221      */

   222     public final static int MILLISECOND_FIELD = 8;

   223     /**

   224      * Useful constant for DAY_OF_WEEK field alignment.

   225      * Used in FieldPosition of date/time formatting.

   226      */

   227     public final static int DAY_OF_WEEK_FIELD = 9;

   228     /**

   229      * Useful constant for DAY_OF_YEAR field alignment.

   230      * Used in FieldPosition of date/time formatting.

   231      */

   232     public final static int DAY_OF_YEAR_FIELD = 10;

   233     /**

   234      * Useful constant for DAY_OF_WEEK_IN_MONTH field alignment.

   235      * Used in FieldPosition of date/time formatting.

   236      */

   237     public final static int DAY_OF_WEEK_IN_MONTH_FIELD = 11;

   238     /**

   239      * Useful constant for WEEK_OF_YEAR field alignment.

   240      * Used in FieldPosition of date/time formatting.

   241      */

   242     public final static int WEEK_OF_YEAR_FIELD = 12;

   243     /**

   244      * Useful constant for WEEK_OF_MONTH field alignment.

   245      * Used in FieldPosition of date/time formatting.

   246      */

   247     public final static int WEEK_OF_MONTH_FIELD = 13;

   248     /**

   249      * Useful constant for AM_PM field alignment.

   250      * Used in FieldPosition of date/time formatting.

   251      */

   252     public final static int AM_PM_FIELD = 14;

   253     /**

   254      * Useful constant for one-based HOUR field alignment.

   255      * Used in FieldPosition of date/time formatting.

   256      * HOUR1_FIELD is used for the one-based 12-hour clock.

   257      * For example, 11:30 PM + 1 hour results in 12:30 AM.

   258      */

   259     public final static int HOUR1_FIELD = 15;

   260     /**

   261      * Useful constant for zero-based HOUR field alignment.

   262      * Used in FieldPosition of date/time formatting.

   263      * HOUR0_FIELD is used for the zero-based 12-hour clock.

   264      * For example, 11:30 PM + 1 hour results in 00:30 AM.

   265      */

   266     public final static int HOUR0_FIELD = 16;

   267     /**

   268      * Useful constant for TIMEZONE field alignment.

   269      * Used in FieldPosition of date/time formatting.

   270      */

   271     public final static int TIMEZONE_FIELD = 17;

   272 

   273     // Proclaim serial compatibility with 1.1 FCS

   274     private static final long serialVersionUID = 7218322306649953788L;

   275 

   276     /**

   277      * Overrides Format.

   278      * Formats a time object into a time string. Examples of time objects

   279      * are a time value expressed in milliseconds and a Date object.

   280      * @param obj must be a Number or a Date.

   281      * @param toAppendTo the string buffer for the returning time string.

   282      * @return the string buffer passed in as toAppendTo, with formatted text appended.

   283      * @param fieldPosition keeps track of the position of the field

   284      * within the returned string.

   285      * On input: an alignment field,

   286      * if desired. On output: the offsets of the alignment field. For

   287      * example, given a time text "1996.07.10 AD at 15:08:56 PDT",

   288      * if the given fieldPosition is DateFormat.YEAR_FIELD, the

   289      * begin index and end index of fieldPosition will be set to

   290      * 0 and 4, respectively.

   291      * Notice that if the same time field appears

   292      * more than once in a pattern, the fieldPosition will be set for the first

   293      * occurrence of that time field. For instance, formatting a Date to

   294      * the time string "1 PM PDT (Pacific Daylight Time)" using the pattern

   295      * "h a z (zzzz)" and the alignment field DateFormat.TIMEZONE_FIELD,

   296      * the begin index and end index of fieldPosition will be set to

   297      * 5 and 8, respectively, for the first occurrence of the timezone

   298      * pattern character 'z'.

   299      * @see java.text.Format

   300      */

   301     public final StringBuffer format(Object obj, StringBuffer toAppendTo,

   302                                      FieldPosition fieldPosition)

   303     {

   304         if (obj instanceof Date)

   305             return format( (Date)obj, toAppendTo, fieldPosition );

   306         else if (obj instanceof Number)

   307             return format( new Date(((Number)obj).longValue()),

   308                           toAppendTo, fieldPosition );

   309         else

   310             throw new IllegalArgumentException("Cannot format given Object as a Date");

   311     }

   312 

   313     /**

   314      * Formats a Date into a date/time string.

   315      * @param date a Date to be formatted into a date/time string.

   316      * @param toAppendTo the string buffer for the returning date/time string.

   317      * @param fieldPosition keeps track of the position of the field

   318      * within the returned string.

   319      * On input: an alignment field,

   320      * if desired. On output: the offsets of the alignment field. For

   321      * example, given a time text "1996.07.10 AD at 15:08:56 PDT",

   322      * if the given fieldPosition is DateFormat.YEAR_FIELD, the

   323      * begin index and end index of fieldPosition will be set to

   324      * 0 and 4, respectively.

   325      * Notice that if the same time field appears

   326      * more than once in a pattern, the fieldPosition will be set for the first

   327      * occurrence of that time field. For instance, formatting a Date to

   328      * the time string "1 PM PDT (Pacific Daylight Time)" using the pattern

   329      * "h a z (zzzz)" and the alignment field DateFormat.TIMEZONE_FIELD,

   330      * the begin index and end index of fieldPosition will be set to

   331      * 5 and 8, respectively, for the first occurrence of the timezone

   332      * pattern character 'z'.

   333      * @return the string buffer passed in as toAppendTo, with formatted text appended.

   334      */

   335     public abstract StringBuffer format(Date date, StringBuffer toAppendTo,

   336                                         FieldPosition fieldPosition);

   337 

   338     /**

   339      * Formats a Date into a date/time string.

   340      * @param date the time value to be formatted into a time string.

   341      * @return the formatted time string.

   342      */

   343     public final String format(Date date)

   344     {

   345         return format(date, new StringBuffer(),

   346                       DontCareFieldPosition.INSTANCE).toString();

   347     }

   348 

   349     /**

   350      * Parses text from the beginning of the given string to produce a date.

   351      * The method may not use the entire text of the given string.

   352      * <p>

   353      * See the {@link #parse(String, ParsePosition)} method for more information

   354      * on date parsing.

   355      *

   356      * @param source A <code>String</code> whose beginning should be parsed.

   357      * @return A <code>Date</code> parsed from the string.

   358      * @exception ParseException if the beginning of the specified string

   359      *            cannot be parsed.

   360      */

   361     public Date parse(String source) throws ParseException

   362     {

   363         ParsePosition pos = new ParsePosition(0);

   364         Date result = parse(source, pos);

   365         if (pos.index == 0)

   366             throw new ParseException("Unparseable date: \"" + source + "\"" ,

   367                 pos.errorIndex);

   368         return result;

   369     }

   370 

   371     /**

   372      * Parse a date/time string according to the given parse position.  For

   373      * example, a time text {@code "07/10/96 4:5 PM, PDT"} will be parsed into a {@code Date}

   374      * that is equivalent to {@code Date(837039900000L)}.

   375      *

   376      * <p> By default, parsing is lenient: If the input is not in the form used

   377      * by this object's format method but can still be parsed as a date, then

   378      * the parse succeeds.  Clients may insist on strict adherence to the

   379      * format by calling {@link #setLenient(boolean) setLenient(false)}.

   380      *

   381      * <p>This parsing operation uses the {@link #calendar} to produce

   382      * a {@code Date}. As a result, the {@code calendar}'s date-time

   383      * fields and the {@code TimeZone} value may have been

   384      * overwritten, depending on subclass implementations. Any {@code

   385      * TimeZone} value that has previously been set by a call to

   386      * {@link #setTimeZone(java.util.TimeZone) setTimeZone} may need

   387      * to be restored for further operations.

   388      *

   389      * @param source  The date/time string to be parsed

   390      *

   391      * @param pos   On input, the position at which to start parsing; on

   392      *              output, the position at which parsing terminated, or the

   393      *              start position if the parse failed.

   394      *

   395      * @return      A {@code Date}, or {@code null} if the input could not be parsed

   396      */

   397     public abstract Date parse(String source, ParsePosition pos);

   398 

   399     /**

   400      * Parses text from a string to produce a <code>Date</code>.

   401      * <p>

   402      * The method attempts to parse text starting at the index given by

   403      * <code>pos</code>.

   404      * If parsing succeeds, then the index of <code>pos</code> is updated

   405      * to the index after the last character used (parsing does not necessarily

   406      * use all characters up to the end of the string), and the parsed

   407      * date is returned. The updated <code>pos</code> can be used to

   408      * indicate the starting point for the next call to this method.

   409      * If an error occurs, then the index of <code>pos</code> is not

   410      * changed, the error index of <code>pos</code> is set to the index of

   411      * the character where the error occurred, and null is returned.

   412      * <p>

   413      * See the {@link #parse(String, ParsePosition)} method for more information

   414      * on date parsing.

   415      *

   416      * @param source A <code>String</code>, part of which should be parsed.

   417      * @param pos A <code>ParsePosition</code> object with index and error

   418      *            index information as described above.

   419      * @return A <code>Date</code> parsed from the string. In case of

   420      *         error, returns null.

   421      * @exception NullPointerException if <code>pos</code> is null.

   422      */

   423     public Object parseObject(String source, ParsePosition pos) {

   424         return parse(source, pos);

   425     }

   426 

   427     /**

   428      * Constant for full style pattern.

   429      */

   430     public static final int FULL = 0;

   431     /**

   432      * Constant for long style pattern.

   433      */

   434     public static final int LONG = 1;

   435     /**

   436      * Constant for medium style pattern.

   437      */

   438     public static final int MEDIUM = 2;

   439     /**

   440      * Constant for short style pattern.

   441      */

   442     public static final int SHORT = 3;

   443     /**

   444      * Constant for default style pattern.  Its value is MEDIUM.

   445      */

   446     public static final int DEFAULT = MEDIUM;

   447 

   448     /**

   449      * Gets the time formatter with the default formatting style

   450      * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.

   451      * <p>This is equivalent to calling

   452      * {@link #getTimeInstance(int, Locale) getTimeInstance(DEFAULT,

   453      *     Locale.getDefault(Locale.Category.FORMAT))}.

   454      * @see java.util.Locale#getDefault(java.util.Locale.Category)

   455      * @see java.util.Locale.Category#FORMAT

   456      * @return a time formatter.

   457      */

   458     public final static DateFormat getTimeInstance()

   459     {

   460         return get(DEFAULT, 0, 1, Locale.getDefault(Locale.Category.FORMAT));

   461     }

   462 

   463     /**

   464      * Gets the time formatter with the given formatting style

   465      * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.

   466      * <p>This is equivalent to calling

   467      * {@link #getTimeInstance(int, Locale) getTimeInstance(style,

   468      *     Locale.getDefault(Locale.Category.FORMAT))}.

   469      * @see java.util.Locale#getDefault(java.util.Locale.Category)

   470      * @see java.util.Locale.Category#FORMAT

   471      * @param style the given formatting style. For example,

   472      * SHORT for "h:mm a" in the US locale.

   473      * @return a time formatter.

   474      */

   475     public final static DateFormat getTimeInstance(int style)

   476     {

   477         return get(style, 0, 1, Locale.getDefault(Locale.Category.FORMAT));

   478     }

   479 

   480     /**

   481      * Gets the time formatter with the given formatting style

   482      * for the given locale.

   483      * @param style the given formatting style. For example,

   484      * SHORT for "h:mm a" in the US locale.

   485      * @param aLocale the given locale.

   486      * @return a time formatter.

   487      */

   488     public final static DateFormat getTimeInstance(int style,

   489                                                  Locale aLocale)

   490     {

   491         return get(style, 0, 1, aLocale);

   492     }

   493 

   494     /**

   495      * Gets the date formatter with the default formatting style

   496      * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.

   497      * <p>This is equivalent to calling

   498      * {@link #getDateInstance(int, Locale) getDateInstance(DEFAULT,

   499      *     Locale.getDefault(Locale.Category.FORMAT))}.

   500      * @see java.util.Locale#getDefault(java.util.Locale.Category)

   501      * @see java.util.Locale.Category#FORMAT

   502      * @return a date formatter.

   503      */

   504     public final static DateFormat getDateInstance()

   505     {

   506         return get(0, DEFAULT, 2, Locale.getDefault(Locale.Category.FORMAT));

   507     }

   508 

   509     /**

   510      * Gets the date formatter with the given formatting style

   511      * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.

   512      * <p>This is equivalent to calling

   513      * {@link #getDateInstance(int, Locale) getDateInstance(style,

   514      *     Locale.getDefault(Locale.Category.FORMAT))}.

   515      * @see java.util.Locale#getDefault(java.util.Locale.Category)

   516      * @see java.util.Locale.Category#FORMAT

   517      * @param style the given formatting style. For example,

   518      * SHORT for "M/d/yy" in the US locale.

   519      * @return a date formatter.

   520      */

   521     public final static DateFormat getDateInstance(int style)

   522     {

   523         return get(0, style, 2, Locale.getDefault(Locale.Category.FORMAT));

   524     }

   525 

   526     /**

   527      * Gets the date formatter with the given formatting style

   528      * for the given locale.

   529      * @param style the given formatting style. For example,

   530      * SHORT for "M/d/yy" in the US locale.

   531      * @param aLocale the given locale.

   532      * @return a date formatter.

   533      */

   534     public final static DateFormat getDateInstance(int style,

   535                                                  Locale aLocale)

   536     {

   537         return get(0, style, 2, aLocale);

   538     }

   539 

   540     /**

   541      * Gets the date/time formatter with the default formatting style

   542      * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.

   543      * <p>This is equivalent to calling

   544      * {@link #getDateTimeInstance(int, int, Locale) getDateTimeInstance(DEFAULT,

   545      *     DEFAULT, Locale.getDefault(Locale.Category.FORMAT))}.

   546      * @see java.util.Locale#getDefault(java.util.Locale.Category)

   547      * @see java.util.Locale.Category#FORMAT

   548      * @return a date/time formatter.

   549      */

   550     public final static DateFormat getDateTimeInstance()

   551     {

   552         return get(DEFAULT, DEFAULT, 3, Locale.getDefault(Locale.Category.FORMAT));

   553     }

   554 

   555     /**

   556      * Gets the date/time formatter with the given date and time

   557      * formatting styles for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.

   558      * <p>This is equivalent to calling

   559      * {@link #getDateTimeInstance(int, int, Locale) getDateTimeInstance(dateStyle,

   560      *     timeStyle, Locale.getDefault(Locale.Category.FORMAT))}.

   561      * @see java.util.Locale#getDefault(java.util.Locale.Category)

   562      * @see java.util.Locale.Category#FORMAT

   563      * @param dateStyle the given date formatting style. For example,

   564      * SHORT for "M/d/yy" in the US locale.

   565      * @param timeStyle the given time formatting style. For example,

   566      * SHORT for "h:mm a" in the US locale.

   567      * @return a date/time formatter.

   568      */

   569     public final static DateFormat getDateTimeInstance(int dateStyle,

   570                                                        int timeStyle)

   571     {

   572         return get(timeStyle, dateStyle, 3, Locale.getDefault(Locale.Category.FORMAT));

   573     }

   574 

   575     /**

   576      * Gets the date/time formatter with the given formatting styles

   577      * for the given locale.

   578      * @param dateStyle the given date formatting style.

   579      * @param timeStyle the given time formatting style.

   580      * @param aLocale the given locale.

   581      * @return a date/time formatter.

   582      */

   583     public final static DateFormat

   584         getDateTimeInstance(int dateStyle, int timeStyle, Locale aLocale)

   585     {

   586         return get(timeStyle, dateStyle, 3, aLocale);

   587     }

   588 

   589     /**

   590      * Get a default date/time formatter that uses the SHORT style for both the

   591      * date and the time.

   592      *

   593      * @return a date/time formatter

   594      */

   595     public final static DateFormat getInstance() {

   596         return getDateTimeInstance(SHORT, SHORT);

   597     }

   598 

   599     /**

   600      * Returns an array of all locales for which the

   601      * <code>get*Instance</code> methods of this class can return

   602      * localized instances.

   603      * The returned array represents the union of locales supported by the Java

   604      * runtime and by installed

   605      * {@link java.text.spi.DateFormatProvider DateFormatProvider} implementations.

   606      * It must contain at least a <code>Locale</code> instance equal to

   607      * {@link java.util.Locale#US Locale.US}.

   608      *

   609      * @return An array of locales for which localized

   610      *         <code>DateFormat</code> instances are available.

   611      */

   612     public static Locale[] getAvailableLocales()

   613     {

   614         LocaleServiceProviderPool pool =

   615             LocaleServiceProviderPool.getPool(DateFormatProvider.class);

   616         return pool.getAvailableLocales();

   617     }

   618 

   619     /**

   620      * Set the calendar to be used by this date format.  Initially, the default

   621      * calendar for the specified or default locale is used.

   622      *

   623      * <p>Any {@link java.util.TimeZone TimeZone} and {@linkplain

   624      * #isLenient() leniency} values that have previously been set are

   625      * overwritten by {@code newCalendar}'s values.

   626      *

   627      * @param newCalendar the new {@code Calendar} to be used by the date format

   628      */

   629     public void setCalendar(Calendar newCalendar)

   630     {

   631         this.calendar = newCalendar;

   632     }

   633 

   634     /**

   635      * Gets the calendar associated with this date/time formatter.

   636      *

   637      * @return the calendar associated with this date/time formatter.

   638      */

   639     public Calendar getCalendar()

   640     {

   641         return calendar;

   642     }

   643 

   644     /**

   645      * Allows you to set the number formatter.

   646      * @param newNumberFormat the given new NumberFormat.

   647      */

   648     public void setNumberFormat(NumberFormat newNumberFormat)

   649     {

   650         this.numberFormat = newNumberFormat;

   651     }

   652 

   653     /**

   654      * Gets the number formatter which this date/time formatter uses to

   655      * format and parse a time.

   656      * @return the number formatter which this date/time formatter uses.

   657      */

   658     public NumberFormat getNumberFormat()

   659     {

   660         return numberFormat;

   661     }

   662 

   663     /**

   664      * Sets the time zone for the calendar of this {@code DateFormat} object.

   665      * This method is equivalent to the following call.

   666      * <blockquote><pre>{@code

   667      * getCalendar().setTimeZone(zone)

   668      * }</pre></blockquote>

   669      *

   670      * <p>The {@code TimeZone} set by this method is overwritten by a

   671      * {@link #setCalendar(java.util.Calendar) setCalendar} call.

   672      *

   673      * <p>The {@code TimeZone} set by this method may be overwritten as

   674      * a result of a call to the parse method.

   675      *

   676      * @param zone the given new time zone.

   677      */

   678     public void setTimeZone(TimeZone zone)

   679     {

   680         calendar.setTimeZone(zone);

   681     }

   682 

   683     /**

   684      * Gets the time zone.

   685      * This method is equivalent to the following call.

   686      * <blockquote><pre>{@code

   687      * getCalendar().getTimeZone()

   688      * }</pre></blockquote>

   689      *

   690      * @return the time zone associated with the calendar of DateFormat.

   691      */

   692     public TimeZone getTimeZone()

   693     {

   694         return calendar.getTimeZone();

   695     }

   696 

   697     /**

   698      * Specify whether or not date/time parsing is to be lenient.  With

   699      * lenient parsing, the parser may use heuristics to interpret inputs that

   700      * do not precisely match this object's format.  With strict parsing,

   701      * inputs must match this object's format.

   702      *

   703      * <p>This method is equivalent to the following call.

   704      * <blockquote><pre>{@code

   705      * getCalendar().setLenient(lenient)

   706      * }</pre></blockquote>

   707      *

   708      * <p>This leniency value is overwritten by a call to {@link

   709      * #setCalendar(java.util.Calendar) setCalendar()}.

   710      *

   711      * @param lenient when {@code true}, parsing is lenient

   712      * @see java.util.Calendar#setLenient(boolean)

   713      */

   714     public void setLenient(boolean lenient)

   715     {

   716         calendar.setLenient(lenient);

   717     }

   718 

   719     /**

   720      * Tell whether date/time parsing is to be lenient.

   721      * This method is equivalent to the following call.

   722      * <blockquote><pre>{@code

   723      * getCalendar().isLenient()

   724      * }</pre></blockquote>

   725      *

   726      * @return {@code true} if the {@link #calendar} is lenient;

   727      *         {@code false} otherwise.

   728      * @see java.util.Calendar#isLenient()

   729      */

   730     public boolean isLenient()

   731     {

   732         return calendar.isLenient();

   733     }

   734 

   735     /**

   736      * Overrides hashCode

   737      */

   738     public int hashCode() {

   739         return numberFormat.hashCode();

   740         // just enough fields for a reasonable distribution

   741     }

   742 

   743     /**

   744      * Overrides equals

   745      */

   746     public boolean equals(Object obj) {

   747         if (this == obj) return true;

   748         if (obj == null || getClass() != obj.getClass()) return false;

   749         DateFormat other = (DateFormat) obj;

   750         return (// calendar.equivalentTo(other.calendar) // THIS API DOESN'T EXIST YET!

   751                 calendar.getFirstDayOfWeek() == other.calendar.getFirstDayOfWeek() &&

   752                 calendar.getMinimalDaysInFirstWeek() == other.calendar.getMinimalDaysInFirstWeek() &&

   753                 calendar.isLenient() == other.calendar.isLenient() &&

   754                 calendar.getTimeZone().equals(other.calendar.getTimeZone()) &&

   755                 numberFormat.equals(other.numberFormat));

   756     }

   757 

   758     /**

   759      * Overrides Cloneable

   760      */

   761     public Object clone()

   762     {

   763         DateFormat other = (DateFormat) super.clone();

   764         other.calendar = (Calendar) calendar.clone();

   765         other.numberFormat = (NumberFormat) numberFormat.clone();

   766         return other;

   767     }

   768 

   769     /**

   770      * Creates a DateFormat with the given time and/or date style in the given

   771      * locale.

   772      * @param timeStyle a value from 0 to 3 indicating the time format,

   773      * ignored if flags is 2

   774      * @param dateStyle a value from 0 to 3 indicating the time format,

   775      * ignored if flags is 1

   776      * @param flags either 1 for a time format, 2 for a date format,

   777      * or 3 for a date/time format

   778      * @param loc the locale for the format

   779      */

   780     private static DateFormat get(int timeStyle, int dateStyle,

   781                                   int flags, Locale loc) {

   782         if ((flags & 1) != 0) {

   783             if (timeStyle < 0 || timeStyle > 3) {

   784                 throw new IllegalArgumentException("Illegal time style " + timeStyle);

   785             }

   786         } else {

   787             timeStyle = -1;

   788         }

   789         if ((flags & 2) != 0) {

   790             if (dateStyle < 0 || dateStyle > 3) {

   791                 throw new IllegalArgumentException("Illegal date style " + dateStyle);

   792             }

   793         } else {

   794             dateStyle = -1;

   795         }

   796 

   797         LocaleProviderAdapter adapter = LocaleProviderAdapter.getAdapter(DateFormatProvider.class, loc);

   798         DateFormat dateFormat = get(adapter, timeStyle, dateStyle, loc);

   799         if (dateFormat == null) {

   800             dateFormat = get(LocaleProviderAdapter.forJRE(), timeStyle, dateStyle, loc);

   801         }

   802         return dateFormat;

   803     }

   804 

   805     private static DateFormat get(LocaleProviderAdapter adapter, int timeStyle, int dateStyle, Locale loc) {

   806         DateFormatProvider provider = adapter.getDateFormatProvider();

   807         DateFormat dateFormat;

   808         if (timeStyle == -1) {

   809             dateFormat = provider.getDateInstance(dateStyle, loc);

   810         } else {

   811             if (dateStyle == -1) {

   812                 dateFormat = provider.getTimeInstance(timeStyle, loc);

   813             } else {

   814                 dateFormat = provider.getDateTimeInstance(dateStyle, timeStyle, loc);

   815             }

   816         }

   817         return dateFormat;

   818     }

   819 

   820     /**

   821      * Create a new date format.

   822      */

   823     protected DateFormat() {}

   824 

   825     /**

   826      * Defines constants that are used as attribute keys in the

   827      * <code>AttributedCharacterIterator</code> returned

   828      * from <code>DateFormat.formatToCharacterIterator</code> and as

   829      * field identifiers in <code>FieldPosition</code>.

   830      * <p>

   831      * The class also provides two methods to map

   832      * between its constants and the corresponding Calendar constants.

   833      *

   834      * @since 1.4

   835      * @see java.util.Calendar

   836      */

   837     public static class Field extends Format.Field {

   838 

   839         // Proclaim serial compatibility with 1.4 FCS

   840         private static final long serialVersionUID = 7441350119349544720L;

   841 

   842         // table of all instances in this class, used by readResolve

   843         private static final Map<String, Field> instanceMap = new HashMap<>(18);

   844         // Maps from Calendar constant (such as Calendar.ERA) to Field

   845         // constant (such as Field.ERA).

   846         private static final Field[] calendarToFieldMapping =

   847                                              new Field[Calendar.FIELD_COUNT];

   848 

   849         /** Calendar field. */

   850         private int calendarField;

   851 

   852         /**

   853          * Returns the <code>Field</code> constant that corresponds to

   854          * the <code>Calendar</code> constant <code>calendarField</code>.

   855          * If there is no direct mapping between the <code>Calendar</code>

   856          * constant and a <code>Field</code>, null is returned.

   857          *

   858          * @throws IllegalArgumentException if <code>calendarField</code> is

   859          *         not the value of a <code>Calendar</code> field constant.

   860          * @param calendarField Calendar field constant

   861          * @return Field instance representing calendarField.

   862          * @see java.util.Calendar

   863          */

   864         public static Field ofCalendarField(int calendarField) {

   865             if (calendarField < 0 || calendarField >=

   866                         calendarToFieldMapping.length) {

   867                 throw new IllegalArgumentException("Unknown Calendar constant "

   868                                                    + calendarField);

   869             }

   870             return calendarToFieldMapping[calendarField];

   871         }

   872 

   873         /**

   874          * Creates a <code>Field</code>.

   875          *

   876          * @param name the name of the <code>Field</code>

   877          * @param calendarField the <code>Calendar</code> constant this

   878          *        <code>Field</code> corresponds to; any value, even one

   879          *        outside the range of legal <code>Calendar</code> values may

   880          *        be used, but <code>-1</code> should be used for values

   881          *        that don't correspond to legal <code>Calendar</code> values

   882          */

   883         protected Field(String name, int calendarField) {

   884             super(name);

   885             this.calendarField = calendarField;

   886             if (this.getClass() == DateFormat.Field.class) {

   887                 instanceMap.put(name, this);

   888                 if (calendarField >= 0) {

   889                     // assert(calendarField < Calendar.FIELD_COUNT);

   890                     calendarToFieldMapping[calendarField] = this;

   891                 }

   892             }

   893         }

   894 

   895         /**

   896          * Returns the <code>Calendar</code> field associated with this

   897          * attribute. For example, if this represents the hours field of

   898          * a <code>Calendar</code>, this would return

   899          * <code>Calendar.HOUR</code>. If there is no corresponding

   900          * <code>Calendar</code> constant, this will return -1.

   901          *

   902          * @return Calendar constant for this field

   903          * @see java.util.Calendar

   904          */

   905         public int getCalendarField() {

   906             return calendarField;

   907         }

   908 

   909         /**

   910          * Resolves instances being deserialized to the predefined constants.

   911          *

   912          * @throws InvalidObjectException if the constant could not be

   913          *         resolved.

   914          * @return resolved DateFormat.Field constant

   915          */

   916         @Override

   917         protected Object readResolve() throws InvalidObjectException {

   918             if (this.getClass() != DateFormat.Field.class) {

   919                 throw new InvalidObjectException("subclass didn't correctly implement readResolve");

   920             }

   921 

   922             Object instance = instanceMap.get(getName());

   923             if (instance != null) {

   924                 return instance;

   925             } else {

   926                 throw new InvalidObjectException("unknown attribute name");

   927             }

   928         }

   929 

   930         //

   931         // The constants

   932         //

   933 

   934         /**

   935          * Constant identifying the era field.

   936          */

   937         public final static Field ERA = new Field("era", Calendar.ERA);

   938 

   939         /**

   940          * Constant identifying the year field.

   941          */

   942         public final static Field YEAR = new Field("year", Calendar.YEAR);

   943 

   944         /**

   945          * Constant identifying the month field.

   946          */

   947         public final static Field MONTH = new Field("month", Calendar.MONTH);

   948 

   949         /**

   950          * Constant identifying the day of month field.

   951          */

   952         public final static Field DAY_OF_MONTH = new

   953                             Field("day of month", Calendar.DAY_OF_MONTH);

   954 

   955         /**

   956          * Constant identifying the hour of day field, where the legal values

   957          * are 1 to 24.

   958          */

   959         public final static Field HOUR_OF_DAY1 = new Field("hour of day 1",-1);

   960 

   961         /**

   962          * Constant identifying the hour of day field, where the legal values

   963          * are 0 to 23.

   964          */

   965         public final static Field HOUR_OF_DAY0 = new

   966                Field("hour of day", Calendar.HOUR_OF_DAY);

   967 

   968         /**

   969          * Constant identifying the minute field.

   970          */

   971         public final static Field MINUTE =new Field("minute", Calendar.MINUTE);

   972 

   973         /**

   974          * Constant identifying the second field.

   975          */

   976         public final static Field SECOND =new Field("second", Calendar.SECOND);

   977 

   978         /**

   979          * Constant identifying the millisecond field.

   980          */

   981         public final static Field MILLISECOND = new

   982                 Field("millisecond", Calendar.MILLISECOND);

   983 

   984         /**

   985          * Constant identifying the day of week field.

   986          */

   987         public final static Field DAY_OF_WEEK = new

   988                 Field("day of week", Calendar.DAY_OF_WEEK);

   989 

   990         /**

   991          * Constant identifying the day of year field.

   992          */

   993         public final static Field DAY_OF_YEAR = new

   994                 Field("day of year", Calendar.DAY_OF_YEAR);

   995 

   996         /**

   997          * Constant identifying the day of week field.

   998          */

   999         public final static Field DAY_OF_WEEK_IN_MONTH =

  1000                      new Field("day of week in month",

  1001                                             Calendar.DAY_OF_WEEK_IN_MONTH);

  1002 

  1003         /**

  1004          * Constant identifying the week of year field.

  1005          */

  1006         public final static Field WEEK_OF_YEAR = new

  1007               Field("week of year", Calendar.WEEK_OF_YEAR);

  1008 

  1009         /**

  1010          * Constant identifying the week of month field.

  1011          */

  1012         public final static Field WEEK_OF_MONTH = new

  1013             Field("week of month", Calendar.WEEK_OF_MONTH);

  1014 

  1015         /**

  1016          * Constant identifying the time of day indicator

  1017          * (e.g. "a.m." or "p.m.") field.

  1018          */

  1019         public final static Field AM_PM = new

  1020                             Field("am pm", Calendar.AM_PM);

  1021 

  1022         /**

  1023          * Constant identifying the hour field, where the legal values are

  1024          * 1 to 12.

  1025          */

  1026         public final static Field HOUR1 = new Field("hour 1", -1);

  1027 

  1028         /**

  1029          * Constant identifying the hour field, where the legal values are

  1030          * 0 to 11.

  1031          */

  1032         public final static Field HOUR0 = new

  1033                             Field("hour", Calendar.HOUR);

  1034 

  1035         /**

  1036          * Constant identifying the time zone field.

  1037          */

  1038         public final static Field TIME_ZONE = new Field("time zone", -1);

  1039     }

  1040 }