    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 */
    017package org.apache.commons.lang3.time;
    018
    019import java.io.IOException;
    020import java.io.ObjectInputStream;
    021import java.io.Serializable;
    022import java.text.DateFormat;
    023import java.text.DateFormatSymbols;
    024import java.text.FieldPosition;
    025import java.text.SimpleDateFormat;
    026import java.util.ArrayList;
    027import java.util.Calendar;
    028import java.util.Date;
    029import java.util.List;
    030import java.util.Locale;
    031import java.util.TimeZone;
    032import java.util.concurrent.ConcurrentHashMap;
    033import java.util.concurrent.ConcurrentMap;
    034
    035import org.apache.commons.lang3.ClassUtils;
    036import org.apache.commons.lang3.LocaleUtils;
    037import org.apache.commons.lang3.exception.ExceptionUtils;
    038
    039/**
    040 * FastDatePrinter is a fast and thread-safe version of
    041 * {@link java.text.SimpleDateFormat}.
    042 *
    043 * <p>To obtain a FastDatePrinter, use {@link FastDateFormat#getInstance(String, TimeZone, Locale)}
    044 * or another variation of the factory methods of {@link FastDateFormat}.</p>
    045 *
    046 * <p>Since FastDatePrinter is thread safe, you can use a static member instance:</p>
    047 * <code>
    048 *     private static final DatePrinter DATE_PRINTER = FastDateFormat.getInstance("yyyy-MM-dd");
    049 * </code>
    050 *
    051 * <p>This class can be used as a direct replacement to
    052 * {@link SimpleDateFormat} in most formatting situations.
    053 * This class is especially useful in multi-threaded server environments.
    054 * {@link SimpleDateFormat} is not thread-safe in any JDK version,
    055 * nor will it be as Sun have closed the bug/RFE.
    056 * </p>
    057 *
    058 * <p>Only formatting is supported by this class, but all patterns are compatible with
    059 * SimpleDateFormat (except time zones and some year patterns - see below).</p>
    060 *
    061 * <p>Java 1.4 introduced a new pattern letter, {@code 'Z'}, to represent
    062 * time zones in RFC822 format (eg. {@code +0800} or {@code -1100}).
    063 * This pattern letter can be used here (on all JDK versions).</p>
    064 *
    065 * <p>In addition, the pattern {@code 'ZZ'} has been made to represent
    066 * ISO 8601 extended format time zones (eg. {@code +08:00} or {@code -11:00}).
    067 * This introduces a minor incompatibility with Java 1.4, but at a gain of
    068 * useful functionality.</p>
    069 *
    070 * <p>Starting with JDK7, ISO 8601 support was added using the pattern {@code 'X'}.
    071 * To maintain compatibility, {@code 'ZZ'} will continue to be supported, but using
    072 * one of the {@code 'X'} formats is recommended.
    073 *
    074 * <p>Javadoc cites for the year pattern: <i>For formatting, if the number of
    075 * pattern letters is 2, the year is truncated to 2 digits; otherwise it is
    076 * interpreted as a number.</i> Starting with Java 1.7 a pattern of 'Y' or
    077 * 'YYY' will be formatted as '2003', while it was '03' in former Java
    078 * versions. FastDatePrinter implements the behavior of Java 7.</p>
    079 *
    080 * @since 3.2
    081 * @see FastDateParser
    082 */
    083public class FastDatePrinter implements DatePrinter, Serializable {
    084    // A lot of the speed in this class comes from caching, but some comes
    085    // from the special int to StringBuffer conversion.
    086    //
    087    // The following produces a padded 2-digit number:
    088    //   buffer.append((char)(value / 10 + '0'));
    089    //   buffer.append((char)(value % 10 + '0'));
    090    //
    091    // Note that the fastest append to StringBuffer is a single char (used here).
    092    // Note that Integer.toString() is not called, the conversion is simply
    093    // taking the value and adding (mathematically) the ASCII value for '0'.
    094    // So, don't change this code! It works and is very fast.
    095
    096    /**
    097     * Inner class to output a constant single character.
    098     */
    099    private static class CharacterLiteral implements Rule {
    100        private final char value;
    101
    102        /**
    103         * Constructs a new instance of {@link CharacterLiteral}
    104         * to hold the specified value.
    105         *
    106         * @param value the character literal
    107         */
    108        CharacterLiteral(final char value) {
    109            this.value = value;
    110        }
    111
    112        /**
    113         * {@inheritDoc}
    114         */
    115        @Override
    116        public void appendTo(final Appendable buffer, final Calendar calendar) throws IOException {
    117            buffer.append(value);
    118        }
    119
    120        /**
    121         * {@inheritDoc}
    122         */
    123        @Override
    124        public int estimateLength() {
    125            return 1;
    126        }
    127    }
    128
    129    /**
    130     * Inner class to output the numeric day in week.
    131     */
    132    private static class DayInWeekField implements NumberRule {
    133        private final NumberRule rule;
    134
    135        DayInWeekField(final NumberRule rule) {
    136            this.rule = rule;
    137        }
    138
    139        @Override
    140        public void appendTo(final Appendable buffer, final Calendar calendar) throws IOException {
    141            final int value = calendar.get(Calendar.DAY_OF_WEEK);
    142            rule.appendTo(buffer, value == Calendar.SUNDAY ? 7 : value - 1);
    143        }
    144
    145        @Override
    146        public void appendTo(final Appendable buffer, final int value) throws IOException {
    147            rule.appendTo(buffer, value);
    148        }
    149
    150        @Override
    151        public int estimateLength() {
    152            return rule.estimateLength();
    153        }
    154    }
    155
    156    /**
    157     * Inner class to output a time zone as a number {@code +/-HHMM}
    158     * or {@code +/-HH:MM}.
    159     */
    160    private static class Iso8601_Rule implements Rule {
    161
    162        // Sign TwoDigitHours or Z
    163        static final Iso8601_Rule ISO8601_HOURS = new Iso8601_Rule(3);
    164        // Sign TwoDigitHours Minutes or Z
    165        static final Iso8601_Rule ISO8601_HOURS_MINUTES = new Iso8601_Rule(5);
    166        // Sign TwoDigitHours : Minutes or Z
    167        static final Iso8601_Rule ISO8601_HOURS_COLON_MINUTES = new Iso8601_Rule(6);
    168
    169        /**
    170         * Factory method for Iso8601_Rules.
    171         *
    172         * @param tokenLen a token indicating the length of the TimeZone String to be formatted.
    173         * @return an Iso8601_Rule that can format TimeZone String of length {@code tokenLen}. If no such
    174         *          rule exists, an IllegalArgumentException will be thrown.
    175         */
    176        static Iso8601_Rule getRule(final int tokenLen) {
    177            switch (tokenLen) {
    178            case 1:
    179                return ISO8601_HOURS;
    180            case 2:
    181                return ISO8601_HOURS_MINUTES;
    182            case 3:
    183                return ISO8601_HOURS_COLON_MINUTES;
    184            default:
    185                throw new IllegalArgumentException("invalid number of X");
    186            }
    187        }
    188
    189        private final int length;
    190
    191        /**
    192         * Constructs an instance of {@code Iso8601_Rule} with the specified properties.
    193         *
    194         * @param length The number of characters in output (unless Z is output)
    195         */
    196        Iso8601_Rule(final int length) {
    197            this.length = length;
    198        }
    199
    200        /**
    201         * {@inheritDoc}
    202         */
    203        @Override
    204        public void appendTo(final Appendable buffer, final Calendar calendar) throws IOException {
    205            int offset = calendar.get(Calendar.ZONE_OFFSET) + calendar.get(Calendar.DST_OFFSET);
    206            if (offset == 0) {
    207                buffer.append("Z");
    208                return;
    209            }
    210
    211            if (offset < 0) {
    212                buffer.append('-');
    213                offset = -offset;
    214            } else {
    215                buffer.append('+');
    216            }
    217
    218            final int hours = offset / (60 * 60 * 1000);
    219            appendDigits(buffer, hours);
    220
    221            if (length<5) {
    222                return;
    223            }
    224
    225            if (length==6) {
    226                buffer.append(':');
    227            }
    228
    229            final int minutes = offset / (60 * 1000) - 60 * hours;
    230            appendDigits(buffer, minutes);
    231        }
    232
    233        /**
    234         * {@inheritDoc}
    235         */
    236        @Override
    237        public int estimateLength() {
    238            return length;
    239        }
    240    }
    241    /**
    242     * Inner class defining a numeric rule.
    243     */
    244    private interface NumberRule extends Rule {
    245        /**
    246         * Appends the specified value to the output buffer based on the rule implementation.
    247         *
    248         * @param buffer the output buffer
    249         * @param value the value to be appended
    250         * @throws IOException if an I/O error occurs.
    251         */
    252        void appendTo(Appendable buffer, int value) throws IOException;
    253    }
    254    /**
    255     * Inner class to output a padded number.
    256     */
    257    private static class PaddedNumberField implements NumberRule {
    258        private final int field;
    259        private final int size;
    260
    261        /**
    262         * Constructs an instance of {@link PaddedNumberField}.
    263         *
    264         * @param field the field
    265         * @param size size of the output field
    266         */
    267        PaddedNumberField(final int field, final int size) {
    268            if (size < 3) {
    269                // Should use UnpaddedNumberField or TwoDigitNumberField.
    270                throw new IllegalArgumentException();
    271            }
    272            this.field = field;
    273            this.size = size;
    274        }
    275
    276        /**
    277         * {@inheritDoc}
    278         */
    279        @Override
    280        public void appendTo(final Appendable buffer, final Calendar calendar) throws IOException {
    281            appendTo(buffer, calendar.get(field));
    282        }
    283
    284        /**
    285         * {@inheritDoc}
    286         */
    287        @Override
    288        public final void appendTo(final Appendable buffer, final int value) throws IOException {
    289            appendFullDigits(buffer, value, size);
    290        }
    291
    292        /**
    293         * {@inheritDoc}
    294         */
    295        @Override
    296        public int estimateLength() {
    297            return size;
    298        }
    299    }
    300    // Rules
    301    /**
    302     * Inner class defining a rule.
    303     */
    304    private interface Rule {
    305        /**
    306         * Appends the value of the specified calendar to the output buffer based on the rule implementation.
    307         *
    308         * @param buf the output buffer
    309         * @param calendar calendar to be appended
    310         * @throws IOException if an I/O error occurs.
    311         */
    312        void appendTo(Appendable buf, Calendar calendar) throws IOException;
    313
    314        /**
    315         * Returns the estimated length of the result.
    316         *
    317         * @return the estimated length
    318         */
    319        int estimateLength();
    320    }
    321
    322    /**
    323     * Inner class to output a constant string.
    324     */
    325    private static class StringLiteral implements Rule {
    326        private final String value;
    327
    328        /**
    329         * Constructs a new instance of {@link StringLiteral}
    330         * to hold the specified value.
    331         *
    332         * @param value the string literal
    333         */
    334        StringLiteral(final String value) {
    335            this.value = value;
    336        }
    337
    338        /**
    339         * {@inheritDoc}
    340         */
    341        @Override
    342        public void appendTo(final Appendable buffer, final Calendar calendar) throws IOException {
    343            buffer.append(value);
    344        }
    345
    346        /**
    347         * {@inheritDoc}
    348         */
    349        @Override
    350        public int estimateLength() {
    351            return value.length();
    352        }
    353    }
    354    /**
    355     * Inner class to output one of a set of values.
    356     */
    357    private static class TextField implements Rule {
    358        private final int field;
    359        private final String[] values;
    360
    361        /**
    362         * Constructs an instance of {@link TextField}
    363         * with the specified field and values.
    364         *
    365         * @param field the field
    366         * @param values the field values
    367         */
    368        TextField(final int field, final String[] values) {
    369            this.field = field;
    370            this.values = values;
    371        }
    372
    373        /**
    374         * {@inheritDoc}
    375         */
    376        @Override
    377        public void appendTo(final Appendable buffer, final Calendar calendar) throws IOException {
    378            buffer.append(values[calendar.get(field)]);
    379        }
    380
    381        /**
    382         * {@inheritDoc}
    383         */
    384        @Override
    385        public int estimateLength() {
    386            int max = 0;
    387            for (int i=values.length; --i >= 0; ) {
    388                final int len = values[i].length();
    389                if (len > max) {
    390                    max = len;
    391                }
    392            }
    393            return max;
    394        }
    395    }
    396    /**
    397     * Inner class that acts as a compound key for time zone names.
    398     */
    399    private static class TimeZoneDisplayKey {
    400        private final TimeZone timeZone;
    401        private final int style;
    402        private final Locale locale;
    403
    404        /**
    405         * Constructs an instance of {@link TimeZoneDisplayKey} with the specified properties.
    406         *
    407         * @param timeZone the time zone
    408         * @param daylight adjust the style for daylight saving time if {@code true}
    409         * @param style the time zone style
    410         * @param locale the time zone locale
    411         */
    412        TimeZoneDisplayKey(final TimeZone timeZone,
    413                           final boolean daylight, final int style, final Locale locale) {
    414            this.timeZone = timeZone;
    415            if (daylight) {
    416                this.style = style | 0x80000000;
    417            } else {
    418                this.style = style;
    419            }
    420            this.locale = LocaleUtils.toLocale(locale);
    421        }
    422
    423        /**
    424         * {@inheritDoc}
    425         */
    426        @Override
    427        public boolean equals(final Object obj) {
    428            if (this == obj) {
    429                return true;
    430            }
    431            if (obj instanceof TimeZoneDisplayKey) {
    432                final TimeZoneDisplayKey other = (TimeZoneDisplayKey) obj;
    433                return
    434                    timeZone.equals(other.timeZone) &&
    435                    style == other.style &&
    436                    locale.equals(other.locale);
    437            }
    438            return false;
    439        }
    440
    441        /**
    442         * {@inheritDoc}
    443         */
    444        @Override
    445        public int hashCode() {
    446            return (style * 31 + locale.hashCode() ) * 31 + timeZone.hashCode();
    447        }
    448    }
    449    /**
    450     * Inner class to output a time zone name.
    451     */
    452    private static class TimeZoneNameRule implements Rule {
    453        private final Locale locale;
    454        private final int style;
    455        private final String standard;
    456        private final String daylight;
    457
    458        /**
    459         * Constructs an instance of {@link TimeZoneNameRule} with the specified properties.
    460         *
    461         * @param timeZone the time zone
    462         * @param locale the locale
    463         * @param style the style
    464         */
    465        TimeZoneNameRule(final TimeZone timeZone, final Locale locale, final int style) {
    466            this.locale = LocaleUtils.toLocale(locale);
    467            this.style = style;
    468            this.standard = getTimeZoneDisplay(timeZone, false, style, locale);
    469            this.daylight = getTimeZoneDisplay(timeZone, true, style, locale);
    470        }
    471
    472        /**
    473         * {@inheritDoc}
    474         */
    475        @Override
    476        public void appendTo(final Appendable buffer, final Calendar calendar) throws IOException {
    477            final TimeZone zone = calendar.getTimeZone();
    478            if (calendar.get(Calendar.DST_OFFSET) == 0) {
    479                buffer.append(getTimeZoneDisplay(zone, false, style, locale));
    480            } else {
    481                buffer.append(getTimeZoneDisplay(zone, true, style, locale));
    482            }
    483        }
    484
    485        /**
    486         * {@inheritDoc}
    487         */
    488        @Override
    489        public int estimateLength() {
    490            // We have no access to the Calendar object that will be passed to
    491            // appendTo so base estimate on the TimeZone passed to the
    492            // constructor
    493            return Math.max(standard.length(), daylight.length());
    494        }
    495    }
    496    /**
    497     * Inner class to output a time zone as a number {@code +/-HHMM}
    498     * or {@code +/-HH:MM}.
    499     */
    500    private static class TimeZoneNumberRule implements Rule {
    501        static final TimeZoneNumberRule INSTANCE_COLON = new TimeZoneNumberRule(true);
    502        static final TimeZoneNumberRule INSTANCE_NO_COLON = new TimeZoneNumberRule(false);
    503
    504        private final boolean colon;
    505
    506        /**
    507         * Constructs an instance of {@link TimeZoneNumberRule} with the specified properties.
    508         *
    509         * @param colon add colon between HH and MM in the output if {@code true}
    510         */
    511        TimeZoneNumberRule(final boolean colon) {
    512            this.colon = colon;
    513        }
    514
    515        /**
    516         * {@inheritDoc}
    517         */
    518        @Override
    519        public void appendTo(final Appendable buffer, final Calendar calendar) throws IOException {
    520
    521            int offset = calendar.get(Calendar.ZONE_OFFSET) + calendar.get(Calendar.DST_OFFSET);
    522
    523            if (offset < 0) {
    524                buffer.append('-');
    525                offset = -offset;
    526            } else {
    527                buffer.append('+');
    528            }
    529
    530            final int hours = offset / (60 * 60 * 1000);
    531            appendDigits(buffer, hours);
    532
    533            if (colon) {
    534                buffer.append(':');
    535            }
    536
    537            final int minutes = offset / (60 * 1000) - 60 * hours;
    538            appendDigits(buffer, minutes);
    539        }
    540
    541        /**
    542         * {@inheritDoc}
    543         */
    544        @Override
    545        public int estimateLength() {
    546            return 5;
    547        }
    548    }
    549
    550    /**
    551     * Inner class to output the twelve hour field.
    552     */
    553    private static class TwelveHourField implements NumberRule {
    554        private final NumberRule rule;
    555
    556        /**
    557         * Constructs an instance of {@link TwelveHourField} with the specified
    558         * {@link NumberRule}.
    559         *
    560         * @param rule the rule
    561         */
    562        TwelveHourField(final NumberRule rule) {
    563            this.rule = rule;
    564        }
    565
    566        /**
    567         * {@inheritDoc}
    568         */
    569        @Override
    570        public void appendTo(final Appendable buffer, final Calendar calendar) throws IOException {
    571            int value = calendar.get(Calendar.HOUR);
    572            if (value == 0) {
    573                value = calendar.getLeastMaximum(Calendar.HOUR) + 1;
    574            }
    575            rule.appendTo(buffer, value);
    576        }
    577
    578        /**
    579         * {@inheritDoc}
    580         */
    581        @Override
    582        public void appendTo(final Appendable buffer, final int value) throws IOException {
    583            rule.appendTo(buffer, value);
    584        }
    585
    586        /**
    587         * {@inheritDoc}
    588         */
    589        @Override
    590        public int estimateLength() {
    591            return rule.estimateLength();
    592        }
    593    }
    594
    595    /**
    596     * Inner class to output the twenty four hour field.
    597     */
    598    private static class TwentyFourHourField implements NumberRule {
    599        private final NumberRule rule;
    600
    601        /**
    602         * Constructs an instance of {@link TwentyFourHourField} with the specified
    603         * {@link NumberRule}.
    604         *
    605         * @param rule the rule
    606         */
    607        TwentyFourHourField(final NumberRule rule) {
    608            this.rule = rule;
    609        }
    610
    611        /**
    612         * {@inheritDoc}
    613         */
    614        @Override
    615        public void appendTo(final Appendable buffer, final Calendar calendar) throws IOException {
    616            int value = calendar.get(Calendar.HOUR_OF_DAY);
    617            if (value == 0) {
    618                value = calendar.getMaximum(Calendar.HOUR_OF_DAY) + 1;
    619            }
    620            rule.appendTo(buffer, value);
    621        }
    622
    623        /**
    624         * {@inheritDoc}
    625         */
    626        @Override
    627        public void appendTo(final Appendable buffer, final int value) throws IOException {
    628            rule.appendTo(buffer, value);
    629        }
    630
    631        /**
    632         * {@inheritDoc}
    633         */
    634        @Override
    635        public int estimateLength() {
    636            return rule.estimateLength();
    637        }
    638    }
    639
    640    /**
    641     * Inner class to output a two digit month.
    642     */
    643    private static class TwoDigitMonthField implements NumberRule {
    644        static final TwoDigitMonthField INSTANCE = new TwoDigitMonthField();
    645
    646        /**
    647         * Constructs an instance of {@link TwoDigitMonthField}.
    648         */
    649        TwoDigitMonthField() {
    650        }
    651
    652        /**
    653         * {@inheritDoc}
    654         */
    655        @Override
    656        public void appendTo(final Appendable buffer, final Calendar calendar) throws IOException {
    657            appendTo(buffer, calendar.get(Calendar.MONTH) + 1);
    658        }
    659
    660        /**
    661         * {@inheritDoc}
    662         */
    663        @Override
    664        public final void appendTo(final Appendable buffer, final int value) throws IOException {
    665            appendDigits(buffer, value);
    666        }
    667
    668        /**
    669         * {@inheritDoc}
    670         */
    671        @Override
    672        public int estimateLength() {
    673            return 2;
    674        }
    675    }
    676
    677    /**
    678     * Inner class to output a two digit number.
    679     */
    680    private static class TwoDigitNumberField implements NumberRule {
    681        private final int field;
    682
    683        /**
    684         * Constructs an instance of {@link TwoDigitNumberField} with the specified field.
    685         *
    686         * @param field the field
    687         */
    688        TwoDigitNumberField(final int field) {
    689            this.field = field;
    690        }
    691
    692        /**
    693         * {@inheritDoc}
    694         */
    695        @Override
    696        public void appendTo(final Appendable buffer, final Calendar calendar) throws IOException {
    697            appendTo(buffer, calendar.get(field));
    698        }
    699
    700        /**
    701         * {@inheritDoc}
    702         */
    703        @Override
    704        public final void appendTo(final Appendable buffer, final int value) throws IOException {
    705            if (value < 100) {
    706                appendDigits(buffer, value);
    707            } else {
    708                appendFullDigits(buffer, value, 2);
    709            }
    710        }
    711
    712        /**
    713         * {@inheritDoc}
    714         */
    715        @Override
    716        public int estimateLength() {
    717            return 2;
    718        }
    719    }
    720
    721    /**
    722     * Inner class to output a two digit year.
    723     */
    724    private static class TwoDigitYearField implements NumberRule {
    725        static final TwoDigitYearField INSTANCE = new TwoDigitYearField();
    726
    727        /**
    728         * Constructs an instance of {@link TwoDigitYearField}.
    729         */
    730        TwoDigitYearField() {
    731        }
    732
    733        /**
    734         * {@inheritDoc}
    735         */
    736        @Override
    737        public void appendTo(final Appendable buffer, final Calendar calendar) throws IOException {
    738            appendTo(buffer, calendar.get(Calendar.YEAR) % 100);
    739        }
    740
    741        /**
    742         * {@inheritDoc}
    743         */
    744        @Override
    745        public final void appendTo(final Appendable buffer, final int value) throws IOException {
    746            appendDigits(buffer, value % 100);
    747        }
    748
    749        /**
    750         * {@inheritDoc}
    751         */
    752        @Override
    753        public int estimateLength() {
    754            return 2;
    755        }
    756    }
    757
    758    /**
    759     * Inner class to output an unpadded month.
    760     */
    761    private static class UnpaddedMonthField implements NumberRule {
    762        static final UnpaddedMonthField INSTANCE = new UnpaddedMonthField();
    763
    764        /**
    765         * Constructs an instance of {@link UnpaddedMonthField}.
    766         *
    767         */
    768        UnpaddedMonthField() {
    769        }
    770
    771        /**
    772         * {@inheritDoc}
    773         */
    774        @Override
    775        public void appendTo(final Appendable buffer, final Calendar calendar) throws IOException {
    776            appendTo(buffer, calendar.get(Calendar.MONTH) + 1);
    777        }
    778
    779        /**
    780         * {@inheritDoc}
    781         */
    782        @Override
    783        public final void appendTo(final Appendable buffer, final int value) throws IOException {
    784            if (value < 10) {
    785                buffer.append((char) (value + '0'));
    786            } else {
    787                appendDigits(buffer, value);
    788            }
    789        }
    790
    791        /**
    792         * {@inheritDoc}
    793         */
    794        @Override
    795        public int estimateLength() {
    796            return 2;
    797        }
    798    }
    799
    800    /**
    801     * Inner class to output an unpadded number.
    802     */
    803    private static class UnpaddedNumberField implements NumberRule {
    804        private final int field;
    805
    806        /**
    807         * Constructs an instance of {@link UnpaddedNumberField} with the specified field.
    808         *
    809         * @param field the field
    810         */
    811        UnpaddedNumberField(final int field) {
    812            this.field = field;
    813        }
    814
    815        /**
    816         * {@inheritDoc}
    817         */
    818        @Override
    819        public void appendTo(final Appendable buffer, final Calendar calendar) throws IOException {
    820            appendTo(buffer, calendar.get(field));
    821        }
    822
    823        /**
    824         * {@inheritDoc}
    825         */
    826        @Override
    827        public final void appendTo(final Appendable buffer, final int value) throws IOException {
    828            if (value < 10) {
    829                buffer.append((char) (value + '0'));
    830            } else if (value < 100) {
    831                appendDigits(buffer, value);
    832            } else {
    833               appendFullDigits(buffer, value, 1);
    834            }
    835        }
    836
    837        /**
    838         * {@inheritDoc}
    839         */
    840        @Override
    841        public int estimateLength() {
    842            return 4;
    843        }
    844    }
    845
    846    /**
    847     * Inner class to output the numeric day in week.
    848     */
    849    private static class WeekYear implements NumberRule {
    850        private final NumberRule rule;
    851
    852        WeekYear(final NumberRule rule) {
    853            this.rule = rule;
    854        }
    855
    856        @Override
    857        public void appendTo(final Appendable buffer, final Calendar calendar) throws IOException {
    858            rule.appendTo(buffer, calendar.getWeekYear());
    859        }
    860
    861        @Override
    862        public void appendTo(final Appendable buffer, final int value) throws IOException {
    863            rule.appendTo(buffer, value);
    864        }
    865
    866        @Override
    867        public int estimateLength() {
    868            return rule.estimateLength();
    869        }
    870    }
    871
    872    /** Empty array. */
    873    private static final Rule[] EMPTY_RULE_ARRAY = {};
    874
    875    /**
    876     * Required for serialization support.
    877     *
    878     * @see java.io.Serializable
    879     */
    880    private static final long serialVersionUID = 1L;
    881
    882    /**
    883     * FULL locale dependent date or time style.
    884     */
    885    public static final int FULL = DateFormat.FULL;
    886
    887    /**
    888     * LONG locale dependent date or time style.
    889     */
    890    public static final int LONG = DateFormat.LONG;
    891
    892    /**
    893     * MEDIUM locale dependent date or time style.
    894     */
    895    public static final int MEDIUM = DateFormat.MEDIUM;
    896
    897    /**
    898     * SHORT locale dependent date or time style.
    899     */
    900    public static final int SHORT = DateFormat.SHORT;
    901
    902    private static final int MAX_DIGITS = 10; // log10(Integer.MAX_VALUE) ~= 9.3
    903
    904    private static final ConcurrentMap<TimeZoneDisplayKey, String> cTimeZoneDisplayCache =
    905        new ConcurrentHashMap<>(7);
    906
    907    /**
    908     * Appends two digits to the given buffer.
    909     *
    910     * @param buffer the buffer to append to.
    911     * @param value the value to append digits from.
    912     * @throws IOException If an I/O error occurs
    913     */
    914    private static void appendDigits(final Appendable buffer, final int value) throws IOException {
    915        buffer.append((char) (value / 10 + '0'));
    916        buffer.append((char) (value % 10 + '0'));
    917    }
    918
    919    /**
    920     * Appends all digits to the given buffer.
    921     *
    922     * @param buffer the buffer to append to.
    923     * @param value the value to append digits from.
    924     * @param minFieldWidth Minimum field width.
    925     * @throws IOException If an I/O error occurs
    926     */
    927    private static void appendFullDigits(final Appendable buffer, int value, int minFieldWidth) throws IOException {
    928        // specialized paths for 1 to 4 digits -> avoid the memory allocation from the temporary work array
    929        // see LANG-1248
    930        if (value < 10000) {
    931            // less memory allocation path works for four digits or less
    932
    933            int nDigits = 4;
    934            if (value < 1000) {
    935                --nDigits;
    936                if (value < 100) {
    937                    --nDigits;
    938                    if (value < 10) {
    939                        --nDigits;
    940                    }
    941                }
    942            }
    943            // left zero pad
    944            for (int i = minFieldWidth - nDigits; i > 0; --i) {
    945                buffer.append('0');
    946            }
    947
    948            switch (nDigits) {
    949            case 4:
    950                buffer.append((char) (value / 1000 + '0'));
    951                value %= 1000;
    952            case 3:
    953                if (value >= 100) {
    954                    buffer.append((char) (value / 100 + '0'));
    955                    value %= 100;
    956                } else {
    957                    buffer.append('0');
    958                }
    959            case 2:
    960                if (value >= 10) {
    961                    buffer.append((char) (value / 10 + '0'));
    962                    value %= 10;
    963                } else {
    964                    buffer.append('0');
    965                }
    966            case 1:
    967                buffer.append((char) (value + '0'));
    968            }
    969        } else {
    970            // more memory allocation path works for any digits
    971
    972            // build up decimal representation in reverse
    973            final char[] work = new char[MAX_DIGITS];
    974            int digit = 0;
    975            while (value != 0) {
    976                work[digit++] = (char) (value % 10 + '0');
    977                value = value / 10;
    978            }
    979
    980            // pad with zeros
    981            while (digit < minFieldWidth) {
    982                buffer.append('0');
    983                --minFieldWidth;
    984            }
    985
    986            // reverse
    987            while (--digit >= 0) {
    988                buffer.append(work[digit]);
    989            }
    990        }
    991    }
    992
    993    /**
    994     * Gets the time zone display name, using a cache for performance.
    995     *
    996     * @param tz  the zone to query
    997     * @param daylight  true if daylight savings
    998     * @param style  the style to use {@code TimeZone.LONG} or {@code TimeZone.SHORT}
    999     * @param locale  the locale to use
    1000     * @return the textual name of the time zone
    1001     */
    1002    static String getTimeZoneDisplay(final TimeZone tz, final boolean daylight, final int style, final Locale locale) {
    1003        final TimeZoneDisplayKey key = new TimeZoneDisplayKey(tz, daylight, style, locale);
    1004        // This is a very slow call, so cache the results.
    1005        return cTimeZoneDisplayCache.computeIfAbsent(key, k -> tz.getDisplayName(daylight, style, locale));
    1006    }
    1007
    1008    /**
    1009     * The pattern.
    1010     */
    1011    private final String pattern;
    1012
    1013    /**
    1014     * The time zone.
    1015     */
    1016    private final TimeZone timeZone;
    1017
    1018    /**
    1019     * The locale.
    1020     */
    1021    private final Locale locale;
    1022
    1023    /**
    1024     * The parsed rules.
    1025     */
    1026    private transient Rule[] rules;
    1027
    1028    /**
    1029     * The estimated maximum length.
    1030     */
    1031    private transient int maxLengthEstimate;
    1032
    1033    // Constructor
    1034    /**
    1035     * Constructs a new FastDatePrinter.
    1036     * Use {@link FastDateFormat#getInstance(String, TimeZone, Locale)}  or another variation of the
    1037     * factory methods of {@link FastDateFormat} to get a cached FastDatePrinter instance.
    1038     *
    1039     * @param pattern  {@link java.text.SimpleDateFormat} compatible pattern
    1040     * @param timeZone  non-null time zone to use
    1041     * @param locale  non-null locale to use
    1042     * @throws NullPointerException if pattern, timeZone, or locale is null.
    1043     */
    1044    protected FastDatePrinter(final String pattern, final TimeZone timeZone, final Locale locale) {
    1045        this.pattern = pattern;
    1046        this.timeZone = timeZone;
    1047        this.locale = LocaleUtils.toLocale(locale);
    1048        init();
    1049    }
    1050
    1051    /**
    1052     * Performs the formatting by applying the rules to the
    1053     * specified calendar.
    1054     *
    1055     * @param calendar  the calendar to format
    1056     * @param buf  the buffer to format into
    1057     * @param <B> the Appendable class type, usually StringBuilder or StringBuffer.
    1058     * @return the specified string buffer
    1059     */
    1060    private <B extends Appendable> B applyRules(final Calendar calendar, final B buf) {
    1061        try {
    1062            for (final Rule rule : rules) {
    1063                rule.appendTo(buf, calendar);
    1064            }
    1065        } catch (final IOException ioe) {
    1066            ExceptionUtils.asRuntimeException(ioe);
    1067        }
    1068        return buf;
    1069    }
    1070
    1071    /**
    1072     * Performs the formatting by applying the rules to the
    1073     * specified calendar.
    1074     *
    1075     * @param calendar the calendar to format
    1076     * @param buf the buffer to format into
    1077     * @return the specified string buffer
    1078     *
    1079     * @deprecated use {@link #format(Calendar)} or {@link #format(Calendar, Appendable)}
    1080     */
    1081    @Deprecated
    1082    protected StringBuffer applyRules(final Calendar calendar, final StringBuffer buf) {
    1083        return (StringBuffer) applyRules(calendar, (Appendable) buf);
    1084    }
    1085
    1086    /**
    1087     * Creates a String representation of the given Calendar by applying the rules of this printer to it.
    1088     * @param c the Calendar to apply the rules to.
    1089     * @return a String representation of the given Calendar.
    1090     */
    1091    private String applyRulesToString(final Calendar c) {
    1092        return applyRules(c, new StringBuilder(maxLengthEstimate)).toString();
    1093    }
    1094
    1095    // Basics
    1096    /**
    1097     * Compares two objects for equality.
    1098     *
    1099     * @param obj  the object to compare to
    1100     * @return {@code true} if equal
    1101     */
    1102    @Override
    1103    public boolean equals(final Object obj) {
    1104        if (!(obj instanceof FastDatePrinter)) {
    1105            return false;
    1106        }
    1107        final FastDatePrinter other = (FastDatePrinter) obj;
    1108        return pattern.equals(other.pattern)
    1109            && timeZone.equals(other.timeZone)
    1110            && locale.equals(other.locale);
    1111    }
    1112
    1113    /* (non-Javadoc)
    1114     * @see org.apache.commons.lang3.time.DatePrinter#format(java.util.Calendar)
    1115     */
    1116    @Override
    1117    public String format(final Calendar calendar) {
    1118        return format(calendar, new StringBuilder(maxLengthEstimate)).toString();
    1119    }
    1120
    1121    /* (non-Javadoc)
    1122     * @see org.apache.commons.lang3.time.DatePrinter#format(java.util.Calendar, Appendable)
    1123     */
    1124    @Override
    1125    public <B extends Appendable> B format(Calendar calendar, final B buf) {
    1126        // do not pass in calendar directly, this will cause TimeZone of FastDatePrinter to be ignored
    1127        if (!calendar.getTimeZone().equals(timeZone)) {
    1128            calendar = (Calendar) calendar.clone();
    1129            calendar.setTimeZone(timeZone);
    1130        }
    1131        return applyRules(calendar, buf);
    1132    }
    1133
    1134    /* (non-Javadoc)
    1135     * @see org.apache.commons.lang3.time.DatePrinter#format(java.util.Calendar, StringBuffer)
    1136     */
    1137    @Override
    1138    public StringBuffer format(final Calendar calendar, final StringBuffer buf) {
    1139        // do not pass in calendar directly, this will cause TimeZone of FastDatePrinter to be ignored
    1140        return format(calendar.getTime(), buf);
    1141    }
    1142
    1143    /* (non-Javadoc)
    1144     * @see org.apache.commons.lang3.time.DatePrinter#format(java.util.Date)
    1145     */
    1146    @Override
    1147    public String format(final Date date) {
    1148        final Calendar c = newCalendar();
    1149        c.setTime(date);
    1150        return applyRulesToString(c);
    1151    }
    1152
    1153    /* (non-Javadoc)
    1154     * @see org.apache.commons.lang3.time.DatePrinter#format(java.util.Date, Appendable)
    1155     */
    1156    @Override
    1157    public <B extends Appendable> B format(final Date date, final B buf) {
    1158        final Calendar c = newCalendar();
    1159        c.setTime(date);
    1160        return applyRules(c, buf);
    1161    }
    1162
    1163    /* (non-Javadoc)
    1164     * @see org.apache.commons.lang3.time.DatePrinter#format(java.util.Date, StringBuffer)
    1165     */
    1166    @Override
    1167    public StringBuffer format(final Date date, final StringBuffer buf) {
    1168        final Calendar c = newCalendar();
    1169        c.setTime(date);
    1170        return (StringBuffer) applyRules(c, (Appendable) buf);
    1171    }
    1172
    1173    /* (non-Javadoc)
    1174     * @see org.apache.commons.lang3.time.DatePrinter#format(long)
    1175     */
    1176    @Override
    1177    public String format(final long millis) {
    1178        final Calendar c = newCalendar();
    1179        c.setTimeInMillis(millis);
    1180        return applyRulesToString(c);
    1181    }
    1182
    1183    /* (non-Javadoc)
    1184     * @see org.apache.commons.lang3.time.DatePrinter#format(long, Appendable)
    1185     */
    1186    @Override
    1187    public <B extends Appendable> B format(final long millis, final B buf) {
    1188        final Calendar c = newCalendar();
    1189        c.setTimeInMillis(millis);
    1190        return applyRules(c, buf);
    1191    }
    1192
    1193    /* (non-Javadoc)
    1194     * @see org.apache.commons.lang3.time.DatePrinter#format(long, StringBuffer)
    1195     */
    1196    @Override
    1197    public StringBuffer format(final long millis, final StringBuffer buf) {
    1198        final Calendar c = newCalendar();
    1199        c.setTimeInMillis(millis);
    1200        return (StringBuffer) applyRules(c, (Appendable) buf);
    1201    }
    1202
    1203    /**
    1204     * Formats a {@link Date}, {@link Calendar} or
    1205     * {@link Long} (milliseconds) object.
    1206     * @since 3.5
    1207     * @param obj  the object to format
    1208     * @return The formatted value.
    1209     */
    1210    String format(final Object obj) {
    1211        if (obj instanceof Date) {
    1212            return format((Date) obj);
    1213        }
    1214        if (obj instanceof Calendar) {
    1215            return format((Calendar) obj);
    1216        }
    1217        if (obj instanceof Long) {
    1218            return format(((Long) obj).longValue());
    1219        }
    1220        throw new IllegalArgumentException("Unknown class: " + ClassUtils.getName(obj, "<null>"));
    1221    }
    1222
    1223    // Format methods
    1224    /**
    1225     * Formats a {@link Date}, {@link Calendar} or
    1226     * {@link Long} (milliseconds) object.
    1227     * @deprecated Use {{@link #format(Date)}, {{@link #format(Calendar)}, {{@link #format(long)}.
    1228     * @param obj  the object to format
    1229     * @param toAppendTo  the buffer to append to
    1230     * @param pos  the position - ignored
    1231     * @return the buffer passed in
    1232     */
    1233    @Deprecated
    1234    @Override
    1235    public StringBuffer format(final Object obj, final StringBuffer toAppendTo, final FieldPosition pos) {
    1236        if (obj instanceof Date) {
    1237            return format((Date) obj, toAppendTo);
    1238        }
    1239        if (obj instanceof Calendar) {
    1240            return format((Calendar) obj, toAppendTo);
    1241        }
    1242        if (obj instanceof Long) {
    1243            return format(((Long) obj).longValue(), toAppendTo);
    1244        }
    1245        throw new IllegalArgumentException("Unknown class: " + ClassUtils.getName(obj, "<null>"));
    1246    }
    1247
    1248    /* (non-Javadoc)
    1249     * @see org.apache.commons.lang3.time.DatePrinter#getLocale()
    1250     */
    1251    @Override
    1252    public Locale getLocale() {
    1253        return locale;
    1254    }
    1255
    1256    /**
    1257     * Gets an estimate for the maximum string length that the
    1258     * formatter will produce.
    1259     *
    1260     * <p>The actual formatted length will almost always be less than or
    1261     * equal to this amount.</p>
    1262     *
    1263     * @return the maximum formatted length
    1264     */
    1265    public int getMaxLengthEstimate() {
    1266        return maxLengthEstimate;
    1267    }
    1268
    1269    // Accessors
    1270    /* (non-Javadoc)
    1271     * @see org.apache.commons.lang3.time.DatePrinter#getPattern()
    1272     */
    1273    @Override
    1274    public String getPattern() {
    1275        return pattern;
    1276    }
    1277
    1278    /* (non-Javadoc)
    1279     * @see org.apache.commons.lang3.time.DatePrinter#getTimeZone()
    1280     */
    1281    @Override
    1282    public TimeZone getTimeZone() {
    1283        return timeZone;
    1284    }
    1285
    1286    /**
    1287     * Returns a hash code compatible with equals.
    1288     *
    1289     * @return a hash code compatible with equals
    1290     */
    1291    @Override
    1292    public int hashCode() {
    1293        return pattern.hashCode() + 13 * (timeZone.hashCode() + 13 * locale.hashCode());
    1294    }
    1295
    1296    /**
    1297     * Initializes the instance for first use.
    1298     */
    1299    private void init() {
    1300        final List<Rule> rulesList = parsePattern();
    1301        rules = rulesList.toArray(EMPTY_RULE_ARRAY);
    1302
    1303        int len = 0;
    1304        for (int i = rules.length; --i >= 0;) {
    1305            len += rules[i].estimateLength();
    1306        }
    1307
    1308        maxLengthEstimate = len;
    1309    }
    1310
    1311
    1312    /**
    1313     * Creates a new Calendar instance.
    1314     * @return a new Calendar instance.
    1315     */
    1316    private Calendar newCalendar() {
    1317        return Calendar.getInstance(timeZone, locale);
    1318    }
    1319
    1320    // Parse the pattern
    1321    /**
    1322     * Returns a list of Rules given a pattern.
    1323     *
    1324     * @return a {@link List} of Rule objects
    1325     * @throws IllegalArgumentException if pattern is invalid
    1326     */
    1327    protected List<Rule> parsePattern() {
    1328        final DateFormatSymbols symbols = new DateFormatSymbols(locale);
    1329        final List<Rule> rules = new ArrayList<>();
    1330
    1331        final String[] ERAs = symbols.getEras();
    1332        final String[] months = symbols.getMonths();
    1333        final String[] shortMonths = symbols.getShortMonths();
    1334        final String[] weekdays = symbols.getWeekdays();
    1335        final String[] shortWeekdays = symbols.getShortWeekdays();
    1336        final String[] AmPmStrings = symbols.getAmPmStrings();
    1337
    1338        final int length = pattern.length();
    1339        final int[] indexRef = new int[1];
    1340
    1341        for (int i = 0; i < length; i++) {
    1342            indexRef[0] = i;
    1343            final String token = parseToken(pattern, indexRef);
    1344            i = indexRef[0];
    1345
    1346            final int tokenLen = token.length();
    1347            if (tokenLen == 0) {
    1348                break;
    1349            }
    1350
    1351            Rule rule;
    1352            final char c = token.charAt(0);
    1353
    1354            switch (c) {
    1355            case 'G': // era designator (text)
    1356                rule = new TextField(Calendar.ERA, ERAs);
    1357                break;
    1358            case 'y': // year (number)
    1359            case 'Y': // week year
    1360                if (tokenLen == 2) {
    1361                    rule = TwoDigitYearField.INSTANCE;
    1362                } else {
    1363                    rule = selectNumberRule(Calendar.YEAR, Math.max(tokenLen, 4));
    1364                }
    1365                if (c == 'Y') {
    1366                    rule = new WeekYear((NumberRule) rule);
    1367                }
    1368                break;
    1369            case 'M': // month in year (text and number)
    1370                if (tokenLen >= 4) {
    1371                    rule = new TextField(Calendar.MONTH, months);
    1372                } else if (tokenLen == 3) {
    1373                    rule = new TextField(Calendar.MONTH, shortMonths);
    1374                } else if (tokenLen == 2) {
    1375                    rule = TwoDigitMonthField.INSTANCE;
    1376                } else {
    1377                    rule = UnpaddedMonthField.INSTANCE;
    1378                }
    1379                break;
    1380            case 'L': // month in year (text and number)
    1381                if (tokenLen >= 4) {
    1382                    rule = new TextField(Calendar.MONTH, CalendarUtils.getInstance(locale).getStandaloneLongMonthNames());
    1383                } else if (tokenLen == 3) {
    1384                    rule = new TextField(Calendar.MONTH, CalendarUtils.getInstance(locale).getStandaloneShortMonthNames());
    1385                } else if (tokenLen == 2) {
    1386                    rule = TwoDigitMonthField.INSTANCE;
    1387                } else {
    1388                    rule = UnpaddedMonthField.INSTANCE;
    1389                }
    1390                break;
    1391            case 'd': // day in month (number)
    1392                rule = selectNumberRule(Calendar.DAY_OF_MONTH, tokenLen);
    1393                break;
    1394            case 'h': // hour in am/pm (number, 1..12)
    1395                rule = new TwelveHourField(selectNumberRule(Calendar.HOUR, tokenLen));
    1396                break;
    1397            case 'H': // hour in day (number, 0..23)
    1398                rule = selectNumberRule(Calendar.HOUR_OF_DAY, tokenLen);
    1399                break;
    1400            case 'm': // minute in hour (number)
    1401                rule = selectNumberRule(Calendar.MINUTE, tokenLen);
    1402                break;
    1403            case 's': // second in minute (number)
    1404                rule = selectNumberRule(Calendar.SECOND, tokenLen);
    1405                break;
    1406            case 'S': // millisecond (number)
    1407                rule = selectNumberRule(Calendar.MILLISECOND, tokenLen);
    1408                break;
    1409            case 'E': // day in week (text)
    1410                rule = new TextField(Calendar.DAY_OF_WEEK, tokenLen < 4 ? shortWeekdays : weekdays);
    1411                break;
    1412            case 'u': // day in week (number)
    1413                rule = new DayInWeekField(selectNumberRule(Calendar.DAY_OF_WEEK, tokenLen));
    1414                break;
    1415            case 'D': // day in year (number)
    1416                rule = selectNumberRule(Calendar.DAY_OF_YEAR, tokenLen);
    1417                break;
    1418            case 'F': // day of week in month (number)
    1419                rule = selectNumberRule(Calendar.DAY_OF_WEEK_IN_MONTH, tokenLen);
    1420                break;
    1421            case 'w': // week in year (number)
    1422                rule = selectNumberRule(Calendar.WEEK_OF_YEAR, tokenLen);
    1423                break;
    1424            case 'W': // week in month (number)
    1425                rule = selectNumberRule(Calendar.WEEK_OF_MONTH, tokenLen);
    1426                break;
    1427            case 'a': // am/pm marker (text)
    1428                rule = new TextField(Calendar.AM_PM, AmPmStrings);
    1429                break;
    1430            case 'k': // hour in day (1..24)
    1431                rule = new TwentyFourHourField(selectNumberRule(Calendar.HOUR_OF_DAY, tokenLen));
    1432                break;
    1433            case 'K': // hour in am/pm (0..11)
    1434                rule = selectNumberRule(Calendar.HOUR, tokenLen);
    1435                break;
    1436            case 'X': // ISO 8601
    1437                rule = Iso8601_Rule.getRule(tokenLen);
    1438                break;
    1439            case 'z': // time zone (text)
    1440                if (tokenLen >= 4) {
    1441                    rule = new TimeZoneNameRule(timeZone, locale, TimeZone.LONG);
    1442                } else {
    1443                    rule = new TimeZoneNameRule(timeZone, locale, TimeZone.SHORT);
    1444                }
    1445                break;
    1446            case 'Z': // time zone (value)
    1447                if (tokenLen == 1) {
    1448                    rule = TimeZoneNumberRule.INSTANCE_NO_COLON;
    1449                } else if (tokenLen == 2) {
    1450                    rule = Iso8601_Rule.ISO8601_HOURS_COLON_MINUTES;
    1451                } else {
    1452                    rule = TimeZoneNumberRule.INSTANCE_COLON;
    1453                }
    1454                break;
    1455            case '\'': // literal text
    1456                final String sub = token.substring(1);
    1457                if (sub.length() == 1) {
    1458                    rule = new CharacterLiteral(sub.charAt(0));
    1459                } else {
    1460                    rule = new StringLiteral(sub);
    1461                }
    1462                break;
    1463            default:
    1464                throw new IllegalArgumentException("Illegal pattern component: " + token);
    1465            }
    1466
    1467            rules.add(rule);
    1468        }
    1469
    1470        return rules;
    1471    }
    1472
    1473    /**
    1474     * Performs the parsing of tokens.
    1475     *
    1476     * @param pattern  the pattern
    1477     * @param indexRef  index references
    1478     * @return parsed token
    1479     */
    1480    protected String parseToken(final String pattern, final int[] indexRef) {
    1481        final StringBuilder buf = new StringBuilder();
    1482
    1483        int i = indexRef[0];
    1484        final int length = pattern.length();
    1485
    1486        char c = pattern.charAt(i);
    1487        if (c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z') {
    1488            // Scan a run of the same character, which indicates a time
    1489            // pattern.
    1490            buf.append(c);
    1491
    1492            while (i + 1 < length) {
    1493                final char peek = pattern.charAt(i + 1);
    1494                if (peek != c) {
    1495                    break;
    1496                }
    1497                buf.append(c);
    1498                i++;
    1499            }
    1500        } else {
    1501            // This will identify token as text.
    1502            buf.append('\'');
    1503
    1504            boolean inLiteral = false;
    1505
    1506            for (; i < length; i++) {
    1507                c = pattern.charAt(i);
    1508
    1509                if (c == '\'') {
    1510                    if (i + 1 < length && pattern.charAt(i + 1) == '\'') {
    1511                        // '' is treated as escaped '
    1512                        i++;
    1513                        buf.append(c);
    1514                    } else {
    1515                        inLiteral = !inLiteral;
    1516                    }
    1517                } else if (!inLiteral &&
    1518                         (c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z')) {
    1519                    i--;
    1520                    break;
    1521                } else {
    1522                    buf.append(c);
    1523                }
    1524            }
    1525        }
    1526
    1527        indexRef[0] = i;
    1528        return buf.toString();
    1529    }
    1530
    1531    // Serializing
    1532    /**
    1533     * Create the object after serialization. This implementation reinitializes the
    1534     * transient properties.
    1535     *
    1536     * @param in ObjectInputStream from which the object is being deserialized.
    1537     * @throws IOException if there is an IO issue.
    1538     * @throws ClassNotFoundException if a class cannot be found.
    1539     */
    1540    private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException {
    1541        in.defaultReadObject();
    1542        init();
    1543    }
    1544
    1545    /**
    1546     * Gets an appropriate rule for the padding required.
    1547     *
    1548     * @param field  the field to get a rule for
    1549     * @param padding  the padding required
    1550     * @return a new rule with the correct padding
    1551     */
    1552    protected NumberRule selectNumberRule(final int field, final int padding) {
    1553        switch (padding) {
    1554        case 1:
    1555            return new UnpaddedNumberField(field);
    1556        case 2:
    1557            return new TwoDigitNumberField(field);
    1558        default:
    1559            return new PaddedNumberField(field, padding);
    1560        }
    1561    }
    1562
    1563    /**
    1564     * Gets a debugging string version of this formatter.
    1565     *
    1566     * @return a debugging string
    1567     */
    1568    @Override
    1569    public String toString() {
    1570        return "FastDatePrinter[" + pattern + "," + locale + "," + timeZone.getID() + "]";
    1571    }
    1572}