    001    /*
    002     * Licensed to the Apache Software Foundation (ASF) under one or more
    003     * contributor license agreements.  See the NOTICE file distributed with
    004     * this work for additional information regarding copyright ownership.
    005     * The ASF licenses this file to You under the Apache License, Version 2.0
    006     * (the "License"); you may not use this file except in compliance with
    007     * the License.  You may obtain a copy of the License at
    008     *
    009     *      http://www.apache.org/licenses/LICENSE-2.0
    010     *
    011     * Unless required by applicable law or agreed to in writing, software
    012     * distributed under the License is distributed on an "AS IS" BASIS,
    013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014     * See the License for the specific language governing permissions and
    015     * limitations under the License.
    016     */
    017    package org.apache.commons.lang3.time;
    018
    019    import java.io.IOException;
    020    import java.io.ObjectInputStream;
    021    import java.text.DateFormat;
    022    import java.text.DateFormatSymbols;
    023    import java.text.FieldPosition;
    024    import java.text.Format;
    025    import java.text.ParsePosition;
    026    import java.text.SimpleDateFormat;
    027    import java.util.ArrayList;
    028    import java.util.Calendar;
    029    import java.util.Date;
    030    import java.util.GregorianCalendar;
    031    import java.util.HashMap;
    032    import java.util.List;
    033    import java.util.Locale;
    034    import java.util.Map;
    035    import java.util.TimeZone;
    036
    037    import org.apache.commons.lang3.Validate;
    038
    039    /**
    040     * <p>FastDateFormat is a fast and thread-safe version of
    041     * {@link java.text.SimpleDateFormat}.</p>
    042     *
    043     * <p>This class can be used as a direct replacement to
    044     * <code>SimpleDateFormat</code> in most formatting situations.
    045     * This class is especially useful in multi-threaded server environments.
    046     * <code>SimpleDateFormat</code> is not thread-safe in any JDK version,
    047     * nor will it be as Sun have closed the bug/RFE.
    048     * </p>
    049     *
    050     * <p>Only formatting is supported, but all patterns are compatible with
    051     * SimpleDateFormat (except time zones - see below).</p>
    052     *
    053     * <p>Java 1.4 introduced a new pattern letter, <code>'Z'</code>, to represent
    054     * time zones in RFC822 format (eg. <code>+0800</code> or <code>-1100</code>).
    055     * This pattern letter can be used here (on all JDK versions).</p>
    056     *
    057     * <p>In addition, the pattern <code>'ZZ'</code> has been made to represent
    058     * ISO8601 full format time zones (eg. <code>+08:00</code> or <code>-11:00</code>).
    059     * This introduces a minor incompatibility with Java 1.4, but at a gain of
    060     * useful functionality.</p>
    061     *
    062     * @author Apache Software Foundation
    063     * @author TeaTrove project
    064     * @author Brian S O'Neill
    065     * @author Sean Schofield
    066     * @author Gary Gregory
    067     * @author Nikolay Metchev
    068     * @since 2.0
    069     * @version $Id: FastDateFormat.java 892161 2009-12-18 07:21:10Z bayard $
    070     */
    071    public class FastDateFormat extends Format {
    072        // A lot of the speed in this class comes from caching, but some comes
    073        // from the special int to StringBuffer conversion.
    074        //
    075        // The following produces a padded 2 digit number:
    076        //   buffer.append((char)(value / 10 + '0'));
    077        //   buffer.append((char)(value % 10 + '0'));
    078        //
    079        // Note that the fastest append to StringBuffer is a single char (used here).
    080        // Note that Integer.toString() is not called, the conversion is simply
    081        // taking the value and adding (mathematically) the ASCII value for '0'.
    082        // So, don't change this code! It works and is very fast.
    083
    084        /**
    085         * Required for serialization support.
    086         *
    087         * @see java.io.Serializable
    088         */
    089        private static final long serialVersionUID = 1L;
    090
    091        /**
    092         * FULL locale dependent date or time style.
    093         */
    094        public static final int FULL = DateFormat.FULL;
    095        /**
    096         * LONG locale dependent date or time style.
    097         */
    098        public static final int LONG = DateFormat.LONG;
    099        /**
    100         * MEDIUM locale dependent date or time style.
    101         */
    102        public static final int MEDIUM = DateFormat.MEDIUM;
    103        /**
    104         * SHORT locale dependent date or time style.
    105         */
    106        public static final int SHORT = DateFormat.SHORT;
    107
    108        //@GuardedBy("this")
    109        private static String cDefaultPattern; // lazily initialised by getInstance()
    110
    111        private static final Map<FastDateFormat, FastDateFormat> cInstanceCache = new HashMap<FastDateFormat, FastDateFormat>(7);
    112        private static final Map<Object, FastDateFormat> cDateInstanceCache = new HashMap<Object, FastDateFormat>(7);
    113        private static final Map<Object, FastDateFormat> cTimeInstanceCache = new HashMap<Object, FastDateFormat>(7);
    114        private static final Map<Object, FastDateFormat> cDateTimeInstanceCache = new HashMap<Object, FastDateFormat>(7);
    115        private static final Map<Object, String> cTimeZoneDisplayCache = new HashMap<Object, String>(7);
    116
    117        /**
    118         * The pattern.
    119         */
    120        private final String mPattern;
    121        /**
    122         * The time zone.
    123         */
    124        private final TimeZone mTimeZone;
    125        /**
    126         * Whether the time zone overrides any on Calendars.
    127         */
    128        private final boolean mTimeZoneForced;
    129        /**
    130         * The locale.
    131         */
    132        private final Locale mLocale;
    133        /**
    134         * Whether the locale overrides the default.
    135         */
    136        private final boolean mLocaleForced;
    137        /**
    138         * The parsed rules.
    139         */
    140        private transient Rule[] mRules;
    141        /**
    142         * The estimated maximum length.
    143         */
    144        private transient int mMaxLengthEstimate;
    145
    146        //-----------------------------------------------------------------------
    147        /**
    148         * <p>Gets a formatter instance using the default pattern in the
    149         * default locale.</p>
    150         *
    151         * @return a date/time formatter
    152         */
    153        public static FastDateFormat getInstance() {
    154            return getInstance(getDefaultPattern(), null, null);
    155        }
    156
    157        /**
    158         * <p>Gets a formatter instance using the specified pattern in the
    159         * default locale.</p>
    160         *
    161         * @param pattern  {@link java.text.SimpleDateFormat} compatible
    162         *  pattern
    163         * @return a pattern based date/time formatter
    164         * @throws IllegalArgumentException if pattern is invalid
    165         */
    166        public static FastDateFormat getInstance(String pattern) {
    167            return getInstance(pattern, null, null);
    168        }
    169
    170        /**
    171         * <p>Gets a formatter instance using the specified pattern and
    172         * time zone.</p>
    173         *
    174         * @param pattern  {@link java.text.SimpleDateFormat} compatible
    175         *  pattern
    176         * @param timeZone  optional time zone, overrides time zone of
    177         *  formatted date
    178         * @return a pattern based date/time formatter
    179         * @throws IllegalArgumentException if pattern is invalid
    180         */
    181        public static FastDateFormat getInstance(String pattern, TimeZone timeZone) {
    182            return getInstance(pattern, timeZone, null);
    183        }
    184
    185        /**
    186         * <p>Gets a formatter instance using the specified pattern and
    187         * locale.</p>
    188         *
    189         * @param pattern  {@link java.text.SimpleDateFormat} compatible
    190         *  pattern
    191         * @param locale  optional locale, overrides system locale
    192         * @return a pattern based date/time formatter
    193         * @throws IllegalArgumentException if pattern is invalid
    194         */
    195        public static FastDateFormat getInstance(String pattern, Locale locale) {
    196            return getInstance(pattern, null, locale);
    197        }
    198
    199        /**
    200         * <p>Gets a formatter instance using the specified pattern, time zone
    201         * and locale.</p>
    202         *
    203         * @param pattern  {@link java.text.SimpleDateFormat} compatible
    204         *  pattern
    205         * @param timeZone  optional time zone, overrides time zone of
    206         *  formatted date
    207         * @param locale  optional locale, overrides system locale
    208         * @return a pattern based date/time formatter
    209         * @throws IllegalArgumentException if pattern is invalid
    210         *  or <code>null</code>
    211         */
    212        public static synchronized FastDateFormat getInstance(String pattern, TimeZone timeZone, Locale locale) {
    213            FastDateFormat emptyFormat = new FastDateFormat(pattern, timeZone, locale);
    214            FastDateFormat format = cInstanceCache.get(emptyFormat);
    215            if (format == null) {
    216                format = emptyFormat;
    217                format.init();  // convert shell format into usable one
    218                cInstanceCache.put(format, format);  // this is OK!
    219            }
    220            return format;
    221        }
    222
    223        //-----------------------------------------------------------------------
    224        /**
    225         * <p>Gets a date formatter instance using the specified style in the
    226         * default time zone and locale.</p>
    227         *
    228         * @param style  date style: FULL, LONG, MEDIUM, or SHORT
    229         * @return a localized standard date formatter
    230         * @throws IllegalArgumentException if the Locale has no date
    231         *  pattern defined
    232         * @since 2.1
    233         */
    234        public static FastDateFormat getDateInstance(int style) {
    235            return getDateInstance(style, null, null);
    236        }
    237
    238        /**
    239         * <p>Gets a date formatter instance using the specified style and
    240         * locale in the default time zone.</p>
    241         *
    242         * @param style  date style: FULL, LONG, MEDIUM, or SHORT
    243         * @param locale  optional locale, overrides system locale
    244         * @return a localized standard date formatter
    245         * @throws IllegalArgumentException if the Locale has no date
    246         *  pattern defined
    247         * @since 2.1
    248         */
    249        public static FastDateFormat getDateInstance(int style, Locale locale) {
    250            return getDateInstance(style, null, locale);
    251        }
    252
    253        /**
    254         * <p>Gets a date formatter instance using the specified style and
    255         * time zone in the default locale.</p>
    256         *
    257         * @param style  date style: FULL, LONG, MEDIUM, or SHORT
    258         * @param timeZone  optional time zone, overrides time zone of
    259         *  formatted date
    260         * @return a localized standard date formatter
    261         * @throws IllegalArgumentException if the Locale has no date
    262         *  pattern defined
    263         * @since 2.1
    264         */
    265        public static FastDateFormat getDateInstance(int style, TimeZone timeZone) {
    266            return getDateInstance(style, timeZone, null);
    267        }
    268        /**
    269         * <p>Gets a date formatter instance using the specified style, time
    270         * zone and locale.</p>
    271         *
    272         * @param style  date style: FULL, LONG, MEDIUM, or SHORT
    273         * @param timeZone  optional time zone, overrides time zone of
    274         *  formatted date
    275         * @param locale  optional locale, overrides system locale
    276         * @return a localized standard date formatter
    277         * @throws IllegalArgumentException if the Locale has no date
    278         *  pattern defined
    279         */
    280        public static synchronized FastDateFormat getDateInstance(int style, TimeZone timeZone, Locale locale) {
    281            Object key = Integer.valueOf(style);
    282            if (timeZone != null) {
    283                key = new Pair(key, timeZone);
    284            }
    285
    286            if (locale == null) {
    287                locale = Locale.getDefault();
    288            }
    289
    290            key = new Pair(key, locale);
    291
    292            FastDateFormat format = cDateInstanceCache.get(key);
    293            if (format == null) {
    294                try {
    295                    SimpleDateFormat formatter = (SimpleDateFormat) DateFormat.getDateInstance(style, locale);
    296                    String pattern = formatter.toPattern();
    297                    format = getInstance(pattern, timeZone, locale);
    298                    cDateInstanceCache.put(key, format);
    299
    300                } catch (ClassCastException ex) {
    301                    throw new IllegalArgumentException("No date pattern for locale: " + locale);
    302                }
    303            }
    304            return format;
    305        }
    306
    307        //-----------------------------------------------------------------------
    308        /**
    309         * <p>Gets a time formatter instance using the specified style in the
    310         * default time zone and locale.</p>
    311         *
    312         * @param style  time style: FULL, LONG, MEDIUM, or SHORT
    313         * @return a localized standard time formatter
    314         * @throws IllegalArgumentException if the Locale has no time
    315         *  pattern defined
    316         * @since 2.1
    317         */
    318        public static FastDateFormat getTimeInstance(int style) {
    319            return getTimeInstance(style, null, null);
    320        }
    321
    322        /**
    323         * <p>Gets a time formatter instance using the specified style and
    324         * locale in the default time zone.</p>
    325         *
    326         * @param style  time style: FULL, LONG, MEDIUM, or SHORT
    327         * @param locale  optional locale, overrides system locale
    328         * @return a localized standard time formatter
    329         * @throws IllegalArgumentException if the Locale has no time
    330         *  pattern defined
    331         * @since 2.1
    332         */
    333        public static FastDateFormat getTimeInstance(int style, Locale locale) {
    334            return getTimeInstance(style, null, locale);
    335        }
    336
    337        /**
    338         * <p>Gets a time formatter instance using the specified style and
    339         * time zone in the default locale.</p>
    340         *
    341         * @param style  time style: FULL, LONG, MEDIUM, or SHORT
    342         * @param timeZone  optional time zone, overrides time zone of
    343         *  formatted time
    344         * @return a localized standard time formatter
    345         * @throws IllegalArgumentException if the Locale has no time
    346         *  pattern defined
    347         * @since 2.1
    348         */
    349        public static FastDateFormat getTimeInstance(int style, TimeZone timeZone) {
    350            return getTimeInstance(style, timeZone, null);
    351        }
    352
    353        /**
    354         * <p>Gets a time formatter instance using the specified style, time
    355         * zone and locale.</p>
    356         *
    357         * @param style  time style: FULL, LONG, MEDIUM, or SHORT
    358         * @param timeZone  optional time zone, overrides time zone of
    359         *  formatted time
    360         * @param locale  optional locale, overrides system locale
    361         * @return a localized standard time formatter
    362         * @throws IllegalArgumentException if the Locale has no time
    363         *  pattern defined
    364         */
    365        public static synchronized FastDateFormat getTimeInstance(int style, TimeZone timeZone, Locale locale) {
    366            Object key = Integer.valueOf(style);
    367            if (timeZone != null) {
    368                key = new Pair(key, timeZone);
    369            }
    370            if (locale != null) {
    371                key = new Pair(key, locale);
    372            }
    373
    374            FastDateFormat format = cTimeInstanceCache.get(key);
    375            if (format == null) {
    376                if (locale == null) {
    377                    locale = Locale.getDefault();
    378                }
    379
    380                try {
    381                    SimpleDateFormat formatter = (SimpleDateFormat) DateFormat.getTimeInstance(style, locale);
    382                    String pattern = formatter.toPattern();
    383                    format = getInstance(pattern, timeZone, locale);
    384                    cTimeInstanceCache.put(key, format);
    385
    386                } catch (ClassCastException ex) {
    387                    throw new IllegalArgumentException("No date pattern for locale: " + locale);
    388                }
    389            }
    390            return format;
    391        }
    392
    393        //-----------------------------------------------------------------------
    394        /**
    395         * <p>Gets a date/time formatter instance using the specified style
    396         * in the default time zone and locale.</p>
    397         *
    398         * @param dateStyle  date style: FULL, LONG, MEDIUM, or SHORT
    399         * @param timeStyle  time style: FULL, LONG, MEDIUM, or SHORT
    400         * @return a localized standard date/time formatter
    401         * @throws IllegalArgumentException if the Locale has no date/time
    402         *  pattern defined
    403         * @since 2.1
    404         */
    405        public static FastDateFormat getDateTimeInstance(
    406                int dateStyle, int timeStyle) {
    407            return getDateTimeInstance(dateStyle, timeStyle, null, null);
    408        }
    409
    410        /**
    411         * <p>Gets a date/time formatter instance using the specified style and
    412         * locale in the default time zone.</p>
    413         *
    414         * @param dateStyle  date style: FULL, LONG, MEDIUM, or SHORT
    415         * @param timeStyle  time style: FULL, LONG, MEDIUM, or SHORT
    416         * @param locale  optional locale, overrides system locale
    417         * @return a localized standard date/time formatter
    418         * @throws IllegalArgumentException if the Locale has no date/time
    419         *  pattern defined
    420         * @since 2.1
    421         */
    422        public static FastDateFormat getDateTimeInstance(
    423                int dateStyle, int timeStyle, Locale locale) {
    424            return getDateTimeInstance(dateStyle, timeStyle, null, locale);
    425        }
    426
    427        /**
    428         * <p>Gets a date/time formatter instance using the specified style and
    429         * time zone in the default locale.</p>
    430         *
    431         * @param dateStyle  date style: FULL, LONG, MEDIUM, or SHORT
    432         * @param timeStyle  time style: FULL, LONG, MEDIUM, or SHORT
    433         * @param timeZone  optional time zone, overrides time zone of
    434         *  formatted date
    435         * @return a localized standard date/time formatter
    436         * @throws IllegalArgumentException if the Locale has no date/time
    437         *  pattern defined
    438         * @since 2.1
    439         */
    440        public static FastDateFormat getDateTimeInstance(
    441                int dateStyle, int timeStyle, TimeZone timeZone) {
    442            return getDateTimeInstance(dateStyle, timeStyle, timeZone, null);
    443        }
    444        /**
    445         * <p>Gets a date/time formatter instance using the specified style,
    446         * time zone and locale.</p>
    447         *
    448         * @param dateStyle  date style: FULL, LONG, MEDIUM, or SHORT
    449         * @param timeStyle  time style: FULL, LONG, MEDIUM, or SHORT
    450         * @param timeZone  optional time zone, overrides time zone of
    451         *  formatted date
    452         * @param locale  optional locale, overrides system locale
    453         * @return a localized standard date/time formatter
    454         * @throws IllegalArgumentException if the Locale has no date/time
    455         *  pattern defined
    456         */
    457        public static synchronized FastDateFormat getDateTimeInstance(int dateStyle, int timeStyle, TimeZone timeZone,
    458                Locale locale) {
    459
    460            Object key = new Pair(Integer.valueOf(dateStyle), Integer.valueOf(timeStyle));
    461            if (timeZone != null) {
    462                key = new Pair(key, timeZone);
    463            }
    464            if (locale == null) {
    465                locale = Locale.getDefault();
    466            }
    467            key = new Pair(key, locale);
    468
    469            FastDateFormat format = cDateTimeInstanceCache.get(key);
    470            if (format == null) {
    471                try {
    472                    SimpleDateFormat formatter = (SimpleDateFormat) DateFormat.getDateTimeInstance(dateStyle, timeStyle,
    473                            locale);
    474                    String pattern = formatter.toPattern();
    475                    format = getInstance(pattern, timeZone, locale);
    476                    cDateTimeInstanceCache.put(key, format);
    477
    478                } catch (ClassCastException ex) {
    479                    throw new IllegalArgumentException("No date time pattern for locale: " + locale);
    480                }
    481            }
    482            return format;
    483        }
    484
    485        //-----------------------------------------------------------------------
    486        /**
    487         * <p>Gets the time zone display name, using a cache for performance.</p>
    488         *
    489         * @param tz  the zone to query
    490         * @param daylight  true if daylight savings
    491         * @param style  the style to use <code>TimeZone.LONG</code>
    492         *  or <code>TimeZone.SHORT</code>
    493         * @param locale  the locale to use
    494         * @return the textual name of the time zone
    495         */
    496        static synchronized String getTimeZoneDisplay(TimeZone tz, boolean daylight, int style, Locale locale) {
    497            Object key = new TimeZoneDisplayKey(tz, daylight, style, locale);
    498            String value = cTimeZoneDisplayCache.get(key);
    499            if (value == null) {
    500                // This is a very slow call, so cache the results.
    501                value = tz.getDisplayName(daylight, style, locale);
    502                cTimeZoneDisplayCache.put(key, value);
    503            }
    504            return value;
    505        }
    506
    507        /**
    508         * <p>Gets the default pattern.</p>
    509         *
    510         * @return the default pattern
    511         */
    512        private static synchronized String getDefaultPattern() {
    513            if (cDefaultPattern == null) {
    514                cDefaultPattern = new SimpleDateFormat().toPattern();
    515            }
    516            return cDefaultPattern;
    517        }
    518
    519        // Constructor
    520        //-----------------------------------------------------------------------
    521        /**
    522         * <p>Constructs a new FastDateFormat.</p>
    523         *
    524         * @param pattern  {@link java.text.SimpleDateFormat} compatible
    525         *  pattern
    526         * @param timeZone  time zone to use, <code>null</code> means use
    527         *  default for <code>Date</code> and value within for
    528         *  <code>Calendar</code>
    529         * @param locale  locale, <code>null</code> means use system
    530         *  default
    531         * @throws IllegalArgumentException if pattern is invalid or
    532         *  <code>null</code>
    533         */
    534        protected FastDateFormat(String pattern, TimeZone timeZone, Locale locale) {
    535            super();
    536            if (pattern == null) {
    537                throw new IllegalArgumentException("The pattern must not be null");
    538            }
    539            mPattern = pattern;
    540
    541            mTimeZoneForced = (timeZone != null);
    542            if (timeZone == null) {
    543                timeZone = TimeZone.getDefault();
    544            }
    545            mTimeZone = timeZone;
    546
    547            mLocaleForced = (locale != null);
    548            if (locale == null) {
    549                locale = Locale.getDefault();
    550            }
    551            mLocale = locale;
    552        }
    553
    554        /**
    555         * <p>Initializes the instance for first use.</p>
    556         */
    557        protected void init() {
    558            List<Rule> rulesList = parsePattern();
    559            mRules = rulesList.toArray(new Rule[rulesList.size()]);
    560
    561            int len = 0;
    562            for (int i=mRules.length; --i >= 0; ) {
    563                len += mRules[i].estimateLength();
    564            }
    565
    566            mMaxLengthEstimate = len;
    567        }
    568
    569        // Parse the pattern
    570        //-----------------------------------------------------------------------
    571        /**
    572         * <p>Returns a list of Rules given a pattern.</p>
    573         *
    574         * @return a <code>List</code> of Rule objects
    575         * @throws IllegalArgumentException if pattern is invalid
    576         */
    577        protected List<Rule> parsePattern() {
    578            DateFormatSymbols symbols = new DateFormatSymbols(mLocale);
    579            List<Rule> rules = new ArrayList<Rule>();
    580
    581            String[] ERAs = symbols.getEras();
    582            String[] months = symbols.getMonths();
    583            String[] shortMonths = symbols.getShortMonths();
    584            String[] weekdays = symbols.getWeekdays();
    585            String[] shortWeekdays = symbols.getShortWeekdays();
    586            String[] AmPmStrings = symbols.getAmPmStrings();
    587
    588            int length = mPattern.length();
    589            int[] indexRef = new int[1];
    590
    591            for (int i = 0; i < length; i++) {
    592                indexRef[0] = i;
    593                String token = parseToken(mPattern, indexRef);
    594                i = indexRef[0];
    595
    596                int tokenLen = token.length();
    597                if (tokenLen == 0) {
    598                    break;
    599                }
    600
    601                Rule rule;
    602                char c = token.charAt(0);
    603
    604                switch (c) {
    605                case 'G': // era designator (text)
    606                    rule = new TextField(Calendar.ERA, ERAs);
    607                    break;
    608                case 'y': // year (number)
    609                    if (tokenLen >= 4) {
    610                        rule = selectNumberRule(Calendar.YEAR, tokenLen);
    611                    } else {
    612                        rule = TwoDigitYearField.INSTANCE;
    613                    }
    614                    break;
    615                case 'M': // month in year (text and number)
    616                    if (tokenLen >= 4) {
    617                        rule = new TextField(Calendar.MONTH, months);
    618                    } else if (tokenLen == 3) {
    619                        rule = new TextField(Calendar.MONTH, shortMonths);
    620                    } else if (tokenLen == 2) {
    621                        rule = TwoDigitMonthField.INSTANCE;
    622                    } else {
    623                        rule = UnpaddedMonthField.INSTANCE;
    624                    }
    625                    break;
    626                case 'd': // day in month (number)
    627                    rule = selectNumberRule(Calendar.DAY_OF_MONTH, tokenLen);
    628                    break;
    629                case 'h': // hour in am/pm (number, 1..12)
    630                    rule = new TwelveHourField(selectNumberRule(Calendar.HOUR, tokenLen));
    631                    break;
    632                case 'H': // hour in day (number, 0..23)
    633                    rule = selectNumberRule(Calendar.HOUR_OF_DAY, tokenLen);
    634                    break;
    635                case 'm': // minute in hour (number)
    636                    rule = selectNumberRule(Calendar.MINUTE, tokenLen);
    637                    break;
    638                case 's': // second in minute (number)
    639                    rule = selectNumberRule(Calendar.SECOND, tokenLen);
    640                    break;
    641                case 'S': // millisecond (number)
    642                    rule = selectNumberRule(Calendar.MILLISECOND, tokenLen);
    643                    break;
    644                case 'E': // day in week (text)
    645                    rule = new TextField(Calendar.DAY_OF_WEEK, tokenLen < 4 ? shortWeekdays : weekdays);
    646                    break;
    647                case 'D': // day in year (number)
    648                    rule = selectNumberRule(Calendar.DAY_OF_YEAR, tokenLen);
    649                    break;
    650                case 'F': // day of week in month (number)
    651                    rule = selectNumberRule(Calendar.DAY_OF_WEEK_IN_MONTH, tokenLen);
    652                    break;
    653                case 'w': // week in year (number)
    654                    rule = selectNumberRule(Calendar.WEEK_OF_YEAR, tokenLen);
    655                    break;
    656                case 'W': // week in month (number)
    657                    rule = selectNumberRule(Calendar.WEEK_OF_MONTH, tokenLen);
    658                    break;
    659                case 'a': // am/pm marker (text)
    660                    rule = new TextField(Calendar.AM_PM, AmPmStrings);
    661                    break;
    662                case 'k': // hour in day (1..24)
    663                    rule = new TwentyFourHourField(selectNumberRule(Calendar.HOUR_OF_DAY, tokenLen));
    664                    break;
    665                case 'K': // hour in am/pm (0..11)
    666                    rule = selectNumberRule(Calendar.HOUR, tokenLen);
    667                    break;
    668                case 'z': // time zone (text)
    669                    if (tokenLen >= 4) {
    670                        rule = new TimeZoneNameRule(mTimeZone, mTimeZoneForced, mLocale, TimeZone.LONG);
    671                    } else {
    672                        rule = new TimeZoneNameRule(mTimeZone, mTimeZoneForced, mLocale, TimeZone.SHORT);
    673                    }
    674                    break;
    675                case 'Z': // time zone (value)
    676                    if (tokenLen == 1) {
    677                        rule = TimeZoneNumberRule.INSTANCE_NO_COLON;
    678                    } else {
    679                        rule = TimeZoneNumberRule.INSTANCE_COLON;
    680                    }
    681                    break;
    682                case '\'': // literal text
    683                    String sub = token.substring(1);
    684                    if (sub.length() == 1) {
    685                        rule = new CharacterLiteral(sub.charAt(0));
    686                    } else {
    687                        rule = new StringLiteral(sub);
    688                    }
    689                    break;
    690                default:
    691                    throw new IllegalArgumentException("Illegal pattern component: " + token);
    692                }
    693
    694                rules.add(rule);
    695            }
    696
    697            return rules;
    698        }
    699
    700        /**
    701         * <p>Performs the parsing of tokens.</p>
    702         *
    703         * @param pattern  the pattern
    704         * @param indexRef  index references
    705         * @return parsed token
    706         */
    707        protected String parseToken(String pattern, int[] indexRef) {
    708            StringBuilder buf = new StringBuilder();
    709
    710            int i = indexRef[0];
    711            int length = pattern.length();
    712
    713            char c = pattern.charAt(i);
    714            if (c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z') {
    715                // Scan a run of the same character, which indicates a time
    716                // pattern.
    717                buf.append(c);
    718
    719                while (i + 1 < length) {
    720                    char peek = pattern.charAt(i + 1);
    721                    if (peek == c) {
    722                        buf.append(c);
    723                        i++;
    724                    } else {
    725                        break;
    726                    }
    727                }
    728            } else {
    729                // This will identify token as text.
    730                buf.append('\'');
    731
    732                boolean inLiteral = false;
    733
    734                for (; i < length; i++) {
    735                    c = pattern.charAt(i);
    736
    737                    if (c == '\'') {
    738                        if (i + 1 < length && pattern.charAt(i + 1) == '\'') {
    739                            // '' is treated as escaped '
    740                            i++;
    741                            buf.append(c);
    742                        } else {
    743                            inLiteral = !inLiteral;
    744                        }
    745                    } else if (!inLiteral &&
    746                             (c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z')) {
    747                        i--;
    748                        break;
    749                    } else {
    750                        buf.append(c);
    751                    }
    752                }
    753            }
    754
    755            indexRef[0] = i;
    756            return buf.toString();
    757        }
    758
    759        /**
    760         * <p>Gets an appropriate rule for the padding required.</p>
    761         *
    762         * @param field  the field to get a rule for
    763         * @param padding  the padding required
    764         * @return a new rule with the correct padding
    765         */
    766        protected NumberRule selectNumberRule(int field, int padding) {
    767            switch (padding) {
    768            case 1:
    769                return new UnpaddedNumberField(field);
    770            case 2:
    771                return new TwoDigitNumberField(field);
    772            default:
    773                return new PaddedNumberField(field, padding);
    774            }
    775        }
    776
    777        // Format methods
    778        //-----------------------------------------------------------------------
    779        /**
    780         * <p>Formats a <code>Date</code>, <code>Calendar</code> or
    781         * <code>Long</code> (milliseconds) object.</p>
    782         *
    783         * @param obj  the object to format
    784         * @param toAppendTo  the buffer to append to
    785         * @param pos  the position - ignored
    786         * @return the buffer passed in
    787         */
    788        @Override
    789        public StringBuffer format(Object obj, StringBuffer toAppendTo, FieldPosition pos) {
    790            if (obj instanceof Date) {
    791                return format((Date) obj, toAppendTo);
    792            } else if (obj instanceof Calendar) {
    793                return format((Calendar) obj, toAppendTo);
    794            } else if (obj instanceof Long) {
    795                return format(((Long) obj).longValue(), toAppendTo);
    796            } else {
    797                throw new IllegalArgumentException("Unknown class: " +
    798                    (obj == null ? "<null>" : obj.getClass().getName()));
    799            }
    800        }
    801
    802        /**
    803         * <p>Formats a millisecond <code>long</code> value.</p>
    804         *
    805         * @param millis  the millisecond value to format
    806         * @return the formatted string
    807         * @since 2.1
    808         */
    809        public String format(long millis) {
    810            return format(new Date(millis));
    811        }
    812
    813        /**
    814         * <p>Formats a <code>Date</code> object.</p>
    815         *
    816         * @param date  the date to format
    817         * @return the formatted string
    818         */
    819        public String format(Date date) {
    820            Calendar c = new GregorianCalendar(mTimeZone);
    821            c.setTime(date);
    822            return applyRules(c, new StringBuffer(mMaxLengthEstimate)).toString();
    823        }
    824
    825        /**
    826         * <p>Formats a <code>Calendar</code> object.</p>
    827         *
    828         * @param calendar  the calendar to format
    829         * @return the formatted string
    830         */
    831        public String format(Calendar calendar) {
    832            return format(calendar, new StringBuffer(mMaxLengthEstimate)).toString();
    833        }
    834
    835        /**
    836         * <p>Formats a milliseond <code>long</code> value into the
    837         * supplied <code>StringBuffer</code>.</p>
    838         *
    839         * @param millis  the millisecond value to format
    840         * @param buf  the buffer to format into
    841         * @return the specified string buffer
    842         * @since 2.1
    843         */
    844        public StringBuffer format(long millis, StringBuffer buf) {
    845            return format(new Date(millis), buf);
    846        }
    847
    848        /**
    849         * <p>Formats a <code>Date</code> object into the
    850         * supplied <code>StringBuffer</code>.</p>
    851         *
    852         * @param date  the date to format
    853         * @param buf  the buffer to format into
    854         * @return the specified string buffer
    855         */
    856        public StringBuffer format(Date date, StringBuffer buf) {
    857            Calendar c = new GregorianCalendar(mTimeZone);
    858            c.setTime(date);
    859            return applyRules(c, buf);
    860        }
    861
    862        /**
    863         * <p>Formats a <code>Calendar</code> object into the
    864         * supplied <code>StringBuffer</code>.</p>
    865         *
    866         * @param calendar  the calendar to format
    867         * @param buf  the buffer to format into
    868         * @return the specified string buffer
    869         */
    870        public StringBuffer format(Calendar calendar, StringBuffer buf) {
    871            if (mTimeZoneForced) {
    872                calendar.getTimeInMillis(); /// LANG-538
    873                calendar = (Calendar) calendar.clone();
    874                calendar.setTimeZone(mTimeZone);
    875            }
    876            return applyRules(calendar, buf);
    877        }
    878
    879        /**
    880         * <p>Performs the formatting by applying the rules to the
    881         * specified calendar.</p>
    882         *
    883         * @param calendar  the calendar to format
    884         * @param buf  the buffer to format into
    885         * @return the specified string buffer
    886         */
    887        protected StringBuffer applyRules(Calendar calendar, StringBuffer buf) {
    888            Rule[] rules = mRules;
    889            int len = mRules.length;
    890            for (int i = 0; i < len; i++) {
    891                rules[i].appendTo(buf, calendar);
    892            }
    893            return buf;
    894        }
    895
    896        // Parsing
    897        //-----------------------------------------------------------------------
    898        /**
    899         * <p>Parsing is not supported.</p>
    900         *
    901         * @param source  the string to parse
    902         * @param pos  the parsing position
    903         * @return <code>null</code> as not supported
    904         */
    905        @Override
    906        public Object parseObject(String source, ParsePosition pos) {
    907            pos.setIndex(0);
    908            pos.setErrorIndex(0);
    909            return null;
    910        }
    911
    912        // Accessors
    913        //-----------------------------------------------------------------------
    914        /**
    915         * <p>Gets the pattern used by this formatter.</p>
    916         *
    917         * @return the pattern, {@link java.text.SimpleDateFormat} compatible
    918         */
    919        public String getPattern() {
    920            return mPattern;
    921        }
    922
    923        /**
    924         * <p>Gets the time zone used by this formatter.</p>
    925         *
    926         * <p>This zone is always used for <code>Date</code> formatting.
    927         * If a <code>Calendar</code> is passed in to be formatted, the
    928         * time zone on that may be used depending on
    929         * {@link #getTimeZoneOverridesCalendar()}.</p>
    930         *
    931         * @return the time zone
    932         */
    933        public TimeZone getTimeZone() {
    934            return mTimeZone;
    935        }
    936
    937        /**
    938         * <p>Returns <code>true</code> if the time zone of the
    939         * calendar overrides the time zone of the formatter.</p>
    940         *
    941         * @return <code>true</code> if time zone of formatter
    942         *  overridden for calendars
    943         */
    944        public boolean getTimeZoneOverridesCalendar() {
    945            return mTimeZoneForced;
    946        }
    947
    948        /**
    949         * <p>Gets the locale used by this formatter.</p>
    950         *
    951         * @return the locale
    952         */
    953        public Locale getLocale() {
    954            return mLocale;
    955        }
    956
    957        /**
    958         * <p>Gets an estimate for the maximum string length that the
    959         * formatter will produce.</p>
    960         *
    961         * <p>The actual formatted length will almost always be less than or
    962         * equal to this amount.</p>
    963         *
    964         * @return the maximum formatted length
    965         */
    966        public int getMaxLengthEstimate() {
    967            return mMaxLengthEstimate;
    968        }
    969
    970        // Basics
    971        //-----------------------------------------------------------------------
    972        /**
    973         * <p>Compares two objects for equality.</p>
    974         *
    975         * @param obj  the object to compare to
    976         * @return <code>true</code> if equal
    977         */
    978        @Override
    979        public boolean equals(Object obj) {
    980            if (obj instanceof FastDateFormat == false) {
    981                return false;
    982            }
    983            FastDateFormat other = (FastDateFormat) obj;
    984            if (
    985                (mPattern == other.mPattern || mPattern.equals(other.mPattern)) &&
    986                (mTimeZone == other.mTimeZone || mTimeZone.equals(other.mTimeZone)) &&
    987                (mLocale == other.mLocale || mLocale.equals(other.mLocale)) &&
    988                (mTimeZoneForced == other.mTimeZoneForced) &&
    989                (mLocaleForced == other.mLocaleForced)
    990                ) {
    991                return true;
    992            }
    993            return false;
    994        }
    995
    996        /**
    997         * <p>Returns a hashcode compatible with equals.</p>
    998         *
    999         * @return a hashcode compatible with equals
    1000         */
    1001        @Override
    1002        public int hashCode() {
    1003            int total = 0;
    1004            total += mPattern.hashCode();
    1005            total += mTimeZone.hashCode();
    1006            total += (mTimeZoneForced ? 1 : 0);
    1007            total += mLocale.hashCode();
    1008            total += (mLocaleForced ? 1 : 0);
    1009            return total;
    1010        }
    1011
    1012        /**
    1013         * <p>Gets a debugging string version of this formatter.</p>
    1014         *
    1015         * @return a debugging string
    1016         */
    1017        @Override
    1018        public String toString() {
    1019            return "FastDateFormat[" + mPattern + "]";
    1020        }
    1021
    1022        // Serializing
    1023        //-----------------------------------------------------------------------
    1024        /**
    1025         * Create the object after serialization. This implementation reinitializes the
    1026         * transient properties.
    1027         *
    1028         * @param in ObjectInputStream from which the object is being deserialized.
    1029         * @throws IOException if there is an IO issue.
    1030         * @throws ClassNotFoundException if a class cannot be found.
    1031         */
    1032        private void readObject(ObjectInputStream in) throws IOException, ClassNotFoundException {
    1033            in.defaultReadObject();
    1034            init();
    1035        }
    1036
    1037        // Rules
    1038        //-----------------------------------------------------------------------
    1039        /**
    1040         * <p>Inner class defining a rule.</p>
    1041         */
    1042        private interface Rule {
    1043            /**
    1044             * Returns the estimated lentgh of the result.
    1045             *
    1046             * @return the estimated length
    1047             */
    1048            int estimateLength();
    1049
    1050            /**
    1051             * Appends the value of the specified calendar to the output buffer based on the rule implementation.
    1052             *
    1053             * @param buffer the output buffer
    1054             * @param calendar calendar to be appended
    1055             */
    1056            void appendTo(StringBuffer buffer, Calendar calendar);
    1057        }
    1058
    1059        /**
    1060         * <p>Inner class defining a numeric rule.</p>
    1061         */
    1062        private interface NumberRule extends Rule {
    1063            /**
    1064             * Appends the specified value to the output buffer based on the rule implementation.
    1065             *
    1066             * @param buffer the output buffer
    1067             * @param value the value to be appended
    1068             */
    1069            void appendTo(StringBuffer buffer, int value);
    1070        }
    1071
    1072        /**
    1073         * <p>Inner class to output a constant single character.</p>
    1074         */
    1075        private static class CharacterLiteral implements Rule {
    1076            private final char mValue;
    1077
    1078            /**
    1079             * Constructs a new instance of <code>CharacterLiteral</code>
    1080             * to hold the specified value.
    1081             *
    1082             * @param value the character literal
    1083             */
    1084            CharacterLiteral(char value) {
    1085                mValue = value;
    1086            }
    1087
    1088            /**
    1089             * {@inheritDoc}
    1090             */
    1091            public int estimateLength() {
    1092                return 1;
    1093            }
    1094
    1095            /**
    1096             * {@inheritDoc}
    1097             */
    1098            public void appendTo(StringBuffer buffer, Calendar calendar) {
    1099                buffer.append(mValue);
    1100            }
    1101        }
    1102
    1103        /**
    1104         * <p>Inner class to output a constant string.</p>
    1105         */
    1106        private static class StringLiteral implements Rule {
    1107            private final String mValue;
    1108
    1109            /**
    1110             * Constructs a new instance of <code>StringLiteral</code>
    1111             * to hold the specified value.
    1112             *
    1113             * @param value the string literal
    1114             */
    1115            StringLiteral(String value) {
    1116                mValue = value;
    1117            }
    1118
    1119            /**
    1120             * {@inheritDoc}
    1121             */
    1122            public int estimateLength() {
    1123                return mValue.length();
    1124            }
    1125
    1126            /**
    1127             * {@inheritDoc}
    1128             */
    1129            public void appendTo(StringBuffer buffer, Calendar calendar) {
    1130                buffer.append(mValue);
    1131            }
    1132        }
    1133
    1134        /**
    1135         * <p>Inner class to output one of a set of values.</p>
    1136         */
    1137        private static class TextField implements Rule {
    1138            private final int mField;
    1139            private final String[] mValues;
    1140
    1141            /**
    1142             * Constructs an instance of <code>TextField</code>
    1143             * with the specified field and values.
    1144             *
    1145             * @param field the field
    1146             * @param values the field values
    1147             */
    1148            TextField(int field, String[] values) {
    1149                mField = field;
    1150                mValues = values;
    1151            }
    1152
    1153            /**
    1154             * {@inheritDoc}
    1155             */
    1156            public int estimateLength() {
    1157                int max = 0;
    1158                for (int i=mValues.length; --i >= 0; ) {
    1159                    int len = mValues[i].length();
    1160                    if (len > max) {
    1161                        max = len;
    1162                    }
    1163                }
    1164                return max;
    1165            }
    1166
    1167            /**
    1168             * {@inheritDoc}
    1169             */
    1170            public void appendTo(StringBuffer buffer, Calendar calendar) {
    1171                buffer.append(mValues[calendar.get(mField)]);
    1172            }
    1173        }
    1174
    1175        /**
    1176         * <p>Inner class to output an unpadded number.</p>
    1177         */
    1178        private static class UnpaddedNumberField implements NumberRule {
    1179            private final int mField;
    1180
    1181            /**
    1182             * Constructs an instance of <code>UnpadedNumberField</code> with the specified field.
    1183             *
    1184             * @param field the field
    1185             */
    1186            UnpaddedNumberField(int field) {
    1187                mField = field;
    1188            }
    1189
    1190            /**
    1191             * {@inheritDoc}
    1192             */
    1193            public int estimateLength() {
    1194                return 4;
    1195            }
    1196
    1197            /**
    1198             * {@inheritDoc}
    1199             */
    1200            public void appendTo(StringBuffer buffer, Calendar calendar) {
    1201                appendTo(buffer, calendar.get(mField));
    1202            }
    1203
    1204            /**
    1205             * {@inheritDoc}
    1206             */
    1207            public final void appendTo(StringBuffer buffer, int value) {
    1208                if (value < 10) {
    1209                    buffer.append((char)(value + '0'));
    1210                } else if (value < 100) {
    1211                    buffer.append((char)(value / 10 + '0'));
    1212                    buffer.append((char)(value % 10 + '0'));
    1213                } else {
    1214                    buffer.append(Integer.toString(value));
    1215                }
    1216            }
    1217        }
    1218
    1219        /**
    1220         * <p>Inner class to output an unpadded month.</p>
    1221         */
    1222        private static class UnpaddedMonthField implements NumberRule {
    1223            static final UnpaddedMonthField INSTANCE = new UnpaddedMonthField();
    1224
    1225            /**
    1226             * Constructs an instance of <code>UnpaddedMonthField</code>.
    1227             *
    1228             */
    1229            UnpaddedMonthField() {
    1230                super();
    1231            }
    1232
    1233            /**
    1234             * {@inheritDoc}
    1235             */
    1236            public int estimateLength() {
    1237                return 2;
    1238            }
    1239
    1240            /**
    1241             * {@inheritDoc}
    1242             */
    1243            public void appendTo(StringBuffer buffer, Calendar calendar) {
    1244                appendTo(buffer, calendar.get(Calendar.MONTH) + 1);
    1245            }
    1246
    1247            /**
    1248             * {@inheritDoc}
    1249             */
    1250            public final void appendTo(StringBuffer buffer, int value) {
    1251                if (value < 10) {
    1252                    buffer.append((char)(value + '0'));
    1253                } else {
    1254                    buffer.append((char)(value / 10 + '0'));
    1255                    buffer.append((char)(value % 10 + '0'));
    1256                }
    1257            }
    1258        }
    1259
    1260        /**
    1261         * <p>Inner class to output a padded number.</p>
    1262         */
    1263        private static class PaddedNumberField implements NumberRule {
    1264            private final int mField;
    1265            private final int mSize;
    1266
    1267            /**
    1268             * Constructs an instance of <code>PaddedNumberField</code>.
    1269             *
    1270             * @param field the field
    1271             * @param size size of the output field
    1272             */
    1273            PaddedNumberField(int field, int size) {
    1274                if (size < 3) {
    1275                    // Should use UnpaddedNumberField or TwoDigitNumberField.
    1276                    throw new IllegalArgumentException();
    1277                }
    1278                mField = field;
    1279                mSize = size;
    1280            }
    1281
    1282            /**
    1283             * {@inheritDoc}
    1284             */
    1285            public int estimateLength() {
    1286                return 4;
    1287            }
    1288
    1289            /**
    1290             * {@inheritDoc}
    1291             */
    1292            public void appendTo(StringBuffer buffer, Calendar calendar) {
    1293                appendTo(buffer, calendar.get(mField));
    1294            }
    1295
    1296            /**
    1297             * {@inheritDoc}
    1298             */
    1299            public final void appendTo(StringBuffer buffer, int value) {
    1300                if (value < 100) {
    1301                    for (int i = mSize; --i >= 2; ) {
    1302                        buffer.append('0');
    1303                    }
    1304                    buffer.append((char)(value / 10 + '0'));
    1305                    buffer.append((char)(value % 10 + '0'));
    1306                } else {
    1307                    int digits;
    1308                    if (value < 1000) {
    1309                        digits = 3;
    1310                    } else {
    1311                        Validate.isTrue(value > -1, "Negative values should not be possible", value);
    1312                        digits = Integer.toString(value).length();
    1313                    }
    1314                    for (int i = mSize; --i >= digits; ) {
    1315                        buffer.append('0');
    1316                    }
    1317                    buffer.append(Integer.toString(value));
    1318                }
    1319            }
    1320        }
    1321
    1322        /**
    1323         * <p>Inner class to output a two digit number.</p>
    1324         */
    1325        private static class TwoDigitNumberField implements NumberRule {
    1326            private final int mField;
    1327
    1328            /**
    1329             * Constructs an instance of <code>TwoDigitNumberField</code> with the specified field.
    1330             *
    1331             * @param field the field
    1332             */
    1333            TwoDigitNumberField(int field) {
    1334                mField = field;
    1335            }
    1336
    1337            /**
    1338             * {@inheritDoc}
    1339             */
    1340            public int estimateLength() {
    1341                return 2;
    1342            }
    1343
    1344            /**
    1345             * {@inheritDoc}
    1346             */
    1347            public void appendTo(StringBuffer buffer, Calendar calendar) {
    1348                appendTo(buffer, calendar.get(mField));
    1349            }
    1350
    1351            /**
    1352             * {@inheritDoc}
    1353             */
    1354            public final void appendTo(StringBuffer buffer, int value) {
    1355                if (value < 100) {
    1356                    buffer.append((char)(value / 10 + '0'));
    1357                    buffer.append((char)(value % 10 + '0'));
    1358                } else {
    1359                    buffer.append(Integer.toString(value));
    1360                }
    1361            }
    1362        }
    1363
    1364        /**
    1365         * <p>Inner class to output a two digit year.</p>
    1366         */
    1367        private static class TwoDigitYearField implements NumberRule {
    1368            static final TwoDigitYearField INSTANCE = new TwoDigitYearField();
    1369
    1370            /**
    1371             * Constructs an instance of <code>TwoDigitYearField</code>.
    1372             */
    1373            TwoDigitYearField() {
    1374                super();
    1375            }
    1376
    1377            /**
    1378             * {@inheritDoc}
    1379             */
    1380            public int estimateLength() {
    1381                return 2;
    1382            }
    1383
    1384            /**
    1385             * {@inheritDoc}
    1386             */
    1387            public void appendTo(StringBuffer buffer, Calendar calendar) {
    1388                appendTo(buffer, calendar.get(Calendar.YEAR) % 100);
    1389            }
    1390
    1391            /**
    1392             * {@inheritDoc}
    1393             */
    1394            public final void appendTo(StringBuffer buffer, int value) {
    1395                buffer.append((char)(value / 10 + '0'));
    1396                buffer.append((char)(value % 10 + '0'));
    1397            }
    1398        }
    1399
    1400        /**
    1401         * <p>Inner class to output a two digit month.</p>
    1402         */
    1403        private static class TwoDigitMonthField implements NumberRule {
    1404            static final TwoDigitMonthField INSTANCE = new TwoDigitMonthField();
    1405
    1406            /**
    1407             * Constructs an instance of <code>TwoDigitMonthField</code>.
    1408             */
    1409            TwoDigitMonthField() {
    1410                super();
    1411            }
    1412
    1413            /**
    1414             * {@inheritDoc}
    1415             */
    1416            public int estimateLength() {
    1417                return 2;
    1418            }
    1419
    1420            /**
    1421             * {@inheritDoc}
    1422             */
    1423            public void appendTo(StringBuffer buffer, Calendar calendar) {
    1424                appendTo(buffer, calendar.get(Calendar.MONTH) + 1);
    1425            }
    1426
    1427            /**
    1428             * {@inheritDoc}
    1429             */
    1430            public final void appendTo(StringBuffer buffer, int value) {
    1431                buffer.append((char)(value / 10 + '0'));
    1432                buffer.append((char)(value % 10 + '0'));
    1433            }
    1434        }
    1435
    1436        /**
    1437         * <p>Inner class to output the twelve hour field.</p>
    1438         */
    1439        private static class TwelveHourField implements NumberRule {
    1440            private final NumberRule mRule;
    1441
    1442            /**
    1443             * Constructs an instance of <code>TwelveHourField</code> with the specified
    1444             * <code>NumberRule</code>.
    1445             *
    1446             * @param rule the rule
    1447             */
    1448            TwelveHourField(NumberRule rule) {
    1449                mRule = rule;
    1450            }
    1451
    1452            /**
    1453             * {@inheritDoc}
    1454             */
    1455            public int estimateLength() {
    1456                return mRule.estimateLength();
    1457            }
    1458
    1459            /**
    1460             * {@inheritDoc}
    1461             */
    1462            public void appendTo(StringBuffer buffer, Calendar calendar) {
    1463                int value = calendar.get(Calendar.HOUR);
    1464                if (value == 0) {
    1465                    value = calendar.getLeastMaximum(Calendar.HOUR) + 1;
    1466                }
    1467                mRule.appendTo(buffer, value);
    1468            }
    1469
    1470            /**
    1471             * {@inheritDoc}
    1472             */
    1473            public void appendTo(StringBuffer buffer, int value) {
    1474                mRule.appendTo(buffer, value);
    1475            }
    1476        }
    1477
    1478        /**
    1479         * <p>Inner class to output the twenty four hour field.</p>
    1480         */
    1481        private static class TwentyFourHourField implements NumberRule {
    1482            private final NumberRule mRule;
    1483
    1484            /**
    1485             * Constructs an instance of <code>TwentyFourHourField</code> with the specified
    1486             * <code>NumberRule</code>.
    1487             *
    1488             * @param rule the rule
    1489             */
    1490            TwentyFourHourField(NumberRule rule) {
    1491                mRule = rule;
    1492            }
    1493
    1494            /**
    1495             * {@inheritDoc}
    1496             */
    1497            public int estimateLength() {
    1498                return mRule.estimateLength();
    1499            }
    1500
    1501            /**
    1502             * {@inheritDoc}
    1503             */
    1504            public void appendTo(StringBuffer buffer, Calendar calendar) {
    1505                int value = calendar.get(Calendar.HOUR_OF_DAY);
    1506                if (value == 0) {
    1507                    value = calendar.getMaximum(Calendar.HOUR_OF_DAY) + 1;
    1508                }
    1509                mRule.appendTo(buffer, value);
    1510            }
    1511
    1512            /**
    1513             * {@inheritDoc}
    1514             */
    1515            public void appendTo(StringBuffer buffer, int value) {
    1516                mRule.appendTo(buffer, value);
    1517            }
    1518        }
    1519
    1520        /**
    1521         * <p>Inner class to output a time zone name.</p>
    1522         */
    1523        private static class TimeZoneNameRule implements Rule {
    1524            private final TimeZone mTimeZone;
    1525            private final boolean mTimeZoneForced;
    1526            private final Locale mLocale;
    1527            private final int mStyle;
    1528            private final String mStandard;
    1529            private final String mDaylight;
    1530
    1531            /**
    1532             * Constructs an instance of <code>TimeZoneNameRule</code> with the specified properties.
    1533             *
    1534             * @param timeZone the time zone
    1535             * @param timeZoneForced if <code>true</code> the time zone is forced into standard and daylight
    1536             * @param locale the locale
    1537             * @param style the style
    1538             */
    1539            TimeZoneNameRule(TimeZone timeZone, boolean timeZoneForced, Locale locale, int style) {
    1540                mTimeZone = timeZone;
    1541                mTimeZoneForced = timeZoneForced;
    1542                mLocale = locale;
    1543                mStyle = style;
    1544
    1545                if (timeZoneForced) {
    1546                    mStandard = getTimeZoneDisplay(timeZone, false, style, locale);
    1547                    mDaylight = getTimeZoneDisplay(timeZone, true, style, locale);
    1548                } else {
    1549                    mStandard = null;
    1550                    mDaylight = null;
    1551                }
    1552            }
    1553
    1554            /**
    1555             * {@inheritDoc}
    1556             */
    1557            public int estimateLength() {
    1558                if (mTimeZoneForced) {
    1559                    return Math.max(mStandard.length(), mDaylight.length());
    1560                } else if (mStyle == TimeZone.SHORT) {
    1561                    return 4;
    1562                } else {
    1563                    return 40;
    1564                }
    1565            }
    1566
    1567            /**
    1568             * {@inheritDoc}
    1569             */
    1570            public void appendTo(StringBuffer buffer, Calendar calendar) {
    1571                if (mTimeZoneForced) {
    1572                    if (mTimeZone.useDaylightTime() && calendar.get(Calendar.DST_OFFSET) != 0) {
    1573                        buffer.append(mDaylight);
    1574                    } else {
    1575                        buffer.append(mStandard);
    1576                    }
    1577                } else {
    1578                    TimeZone timeZone = calendar.getTimeZone();
    1579                    if (timeZone.useDaylightTime() && calendar.get(Calendar.DST_OFFSET) != 0) {
    1580                        buffer.append(getTimeZoneDisplay(timeZone, true, mStyle, mLocale));
    1581                    } else {
    1582                        buffer.append(getTimeZoneDisplay(timeZone, false, mStyle, mLocale));
    1583                    }
    1584                }
    1585            }
    1586        }
    1587
    1588        /**
    1589         * <p>Inner class to output a time zone as a number <code>+/-HHMM</code>
    1590         * or <code>+/-HH:MM</code>.</p>
    1591         */
    1592        private static class TimeZoneNumberRule implements Rule {
    1593            static final TimeZoneNumberRule INSTANCE_COLON = new TimeZoneNumberRule(true);
    1594            static final TimeZoneNumberRule INSTANCE_NO_COLON = new TimeZoneNumberRule(false);
    1595
    1596            final boolean mColon;
    1597
    1598            /**
    1599             * Constructs an instance of <code>TimeZoneNumberRule</code> with the specified properties.
    1600             *
    1601             * @param colon add colon between HH and MM in the output if <code>true</code>
    1602             */
    1603            TimeZoneNumberRule(boolean colon) {
    1604                mColon = colon;
    1605            }
    1606
    1607            /**
    1608             * {@inheritDoc}
    1609             */
    1610            public int estimateLength() {
    1611                return 5;
    1612            }
    1613
    1614            /**
    1615             * {@inheritDoc}
    1616             */
    1617            public void appendTo(StringBuffer buffer, Calendar calendar) {
    1618                int offset = calendar.get(Calendar.ZONE_OFFSET) + calendar.get(Calendar.DST_OFFSET);
    1619
    1620                if (offset < 0) {
    1621                    buffer.append('-');
    1622                    offset = -offset;
    1623                } else {
    1624                    buffer.append('+');
    1625                }
    1626
    1627                int hours = offset / (60 * 60 * 1000);
    1628                buffer.append((char)(hours / 10 + '0'));
    1629                buffer.append((char)(hours % 10 + '0'));
    1630
    1631                if (mColon) {
    1632                    buffer.append(':');
    1633                }
    1634
    1635                int minutes = offset / (60 * 1000) - 60 * hours;
    1636                buffer.append((char)(minutes / 10 + '0'));
    1637                buffer.append((char)(minutes % 10 + '0'));
    1638            }
    1639        }
    1640
    1641        // ----------------------------------------------------------------------
    1642        /**
    1643         * <p>Inner class that acts as a compound key for time zone names.</p>
    1644         */
    1645        private static class TimeZoneDisplayKey {
    1646            private final TimeZone mTimeZone;
    1647            private final int mStyle;
    1648            private final Locale mLocale;
    1649
    1650            /**
    1651             * Constructs an instance of <code>TimeZoneDisplayKey</code> with the specified properties.
    1652             *
    1653             * @param timeZone the time zone
    1654             * @param daylight adjust the style for daylight saving time if <code>true</code>
    1655             * @param style the timezone style
    1656             * @param locale the timezone locale
    1657             */
    1658            TimeZoneDisplayKey(TimeZone timeZone,
    1659                               boolean daylight, int style, Locale locale) {
    1660                mTimeZone = timeZone;
    1661                if (daylight) {
    1662                    style |= 0x80000000;
    1663                }
    1664                mStyle = style;
    1665                mLocale = locale;
    1666            }
    1667
    1668            /**
    1669             * {@inheritDoc}
    1670             */
    1671            @Override
    1672            public int hashCode() {
    1673                return mStyle * 31 + mLocale.hashCode();
    1674            }
    1675
    1676            /**
    1677             * {@inheritDoc}
    1678             */
    1679            @Override
    1680            public boolean equals(Object obj) {
    1681                if (this == obj) {
    1682                    return true;
    1683                }
    1684                if (obj instanceof TimeZoneDisplayKey) {
    1685                    TimeZoneDisplayKey other = (TimeZoneDisplayKey)obj;
    1686                    return
    1687                        mTimeZone.equals(other.mTimeZone) &&
    1688                        mStyle == other.mStyle &&
    1689                        mLocale.equals(other.mLocale);
    1690                }
    1691                return false;
    1692            }
    1693        }
    1694
    1695        // ----------------------------------------------------------------------
    1696        /**
    1697         * <p>Helper class for creating compound objects.</p>
    1698         *
    1699         * <p>One use for this class is to create a hashtable key
    1700         * out of multiple objects.</p>
    1701         */
    1702        private static class Pair {
    1703            private final Object mObj1;
    1704            private final Object mObj2;
    1705
    1706            /**
    1707             * Constructs an instance of <code>Pair</code> to hold the specified objects.
    1708             * @param obj1 one object in the pair
    1709             * @param obj2 second object in the pair
    1710             */
    1711            public Pair(Object obj1, Object obj2) {
    1712                mObj1 = obj1;
    1713                mObj2 = obj2;
    1714            }
    1715
    1716            /**
    1717             * {@inheritDoc}
    1718             */
    1719            @Override
    1720            public boolean equals(Object obj) {
    1721                if (this == obj) {
    1722                    return true;
    1723                }
    1724
    1725                if (!(obj instanceof Pair)) {
    1726                    return false;
    1727                }
    1728
    1729                Pair key = (Pair)obj;
    1730
    1731                return
    1732                    (mObj1 == null ?
    1733                     key.mObj1 == null : mObj1.equals(key.mObj1)) &&
    1734                    (mObj2 == null ?
    1735                     key.mObj2 == null : mObj2.equals(key.mObj2));
    1736            }
    1737
    1738            /**
    1739             * {@inheritDoc}
    1740             */
    1741            @Override
    1742            public int hashCode() {
    1743                return
    1744                    (mObj1 == null ? 0 : mObj1.hashCode()) +
    1745                    (mObj2 == null ? 0 : mObj2.hashCode());
    1746            }
    1747
    1748            /**
    1749             * {@inheritDoc}
    1750             */
    1751            @Override
    1752            public String toString() {
    1753                return "[" + mObj1 + ':' + mObj2 + ']';
    1754            }
    1755        }
    1756
    1757    }