• SimpleDateFormat


    SimpleDateFormat

    /*
     * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
     * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
     */
    
    /*
     * (C) Copyright Taligent, Inc. 1996 - All Rights Reserved
     * (C) Copyright IBM Corp. 1996-1998 - All Rights Reserved
     *
     *   The original version of this source code and documentation is copyrighted
     * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
     * materials are provided under terms of a License Agreement between Taligent
     * and Sun. This technology is protected by multiple US and International
     * patents. This notice and attribution to Taligent may not be removed.
     *   Taligent is a registered trademark of Taligent, Inc.
     *
     */
    
    package java.text;
    
    import java.io.IOException;
    import java.io.InvalidObjectException;
    import java.io.ObjectInputStream;
    import static java.text.DateFormatSymbols.*;
    import java.util.Calendar;
    import java.util.Date;
    import java.util.GregorianCalendar;
    import java.util.Locale;
    import java.util.Map;
    import java.util.SimpleTimeZone;
    import java.util.SortedMap;
    import java.util.TimeZone;
    import java.util.concurrent.ConcurrentHashMap;
    import java.util.concurrent.ConcurrentMap;
    import sun.util.calendar.CalendarUtils;
    import sun.util.calendar.ZoneInfoFile;
    import sun.util.locale.provider.LocaleProviderAdapter;
    
    /**
     * <code>SimpleDateFormat</code> is a concrete class for formatting and
     * parsing dates in a locale-sensitive manner. It allows for formatting
     * (date → text), parsing (text → date), and normalization.
     *
     * <p>
     * <code>SimpleDateFormat</code> allows you to start by choosing
     * any user-defined patterns for date-time formatting. However, you
     * are encouraged to create a date-time formatter with either
     * <code>getTimeInstance</code>, <code>getDateInstance</code>, or
     * <code>getDateTimeInstance</code> in <code>DateFormat</code>. Each
     * of these class methods can return a date/time formatter initialized
     * with a default format pattern. You may modify the format pattern
     * using the <code>applyPattern</code> methods as desired.
     * For more information on using these methods, see
     * {@link DateFormat}.
     *
     * <h3>Date and Time Patterns</h3>
     * <p>
     * Date and time formats are specified by <em>date and time pattern</em>
     * strings.
     * Within date and time pattern strings, unquoted letters from
     * <code>'A'</code> to <code>'Z'</code> and from <code>'a'</code> to
     * <code>'z'</code> are interpreted as pattern letters representing the
     * components of a date or time string.
     * Text can be quoted using single quotes (<code>'</code>) to avoid
     * interpretation.
     * <code>"''"</code> represents a single quote.
     * All other characters are not interpreted; they're simply copied into the
     * output string during formatting or matched against the input string
     * during parsing.
     * <p>
     * The following pattern letters are defined (all other characters from
     * <code>'A'</code> to <code>'Z'</code> and from <code>'a'</code> to
     * <code>'z'</code> are reserved):
     * <blockquote>
     * <table border=0 cellspacing=3 cellpadding=0 summary="Chart shows pattern letters, date/time component, presentation, and examples.">
     *     <tr style="background-color: rgb(204, 204, 255);">
     *         <th align=left>Letter
     *         <th align=left>Date or Time Component
     *         <th align=left>Presentation
     *         <th align=left>Examples
     *     <tr>
     *         <td><code>G</code>
     *         <td>Era designator
     *         <td><a href="#text">Text</a>
     *         <td><code>AD</code>
     *     <tr style="background-color: rgb(238, 238, 255);">
     *         <td><code>y</code>
     *         <td>Year
     *         <td><a href="#year">Year</a>
     *         <td><code>1996</code>; <code>96</code>
     *     <tr>
     *         <td><code>Y</code>
     *         <td>Week year
     *         <td><a href="#year">Year</a>
     *         <td><code>2009</code>; <code>09</code>
     *     <tr style="background-color: rgb(238, 238, 255);">
     *         <td><code>M</code>
     *         <td>Month in year (context sensitive)
     *         <td><a href="#month">Month</a>
     *         <td><code>July</code>; <code>Jul</code>; <code>07</code>
     *     <tr>
     *         <td><code>L</code>
     *         <td>Month in year (standalone form)
     *         <td><a href="#month">Month</a>
     *         <td><code>July</code>; <code>Jul</code>; <code>07</code>
     *     <tr style="background-color: rgb(238, 238, 255);">
     *         <td><code>w</code>
     *         <td>Week in year
     *         <td><a href="#number">Number</a>
     *         <td><code>27</code>
     *     <tr>
     *         <td><code>W</code>
     *         <td>Week in month
     *         <td><a href="#number">Number</a>
     *         <td><code>2</code>
     *     <tr style="background-color: rgb(238, 238, 255);">
     *         <td><code>D</code>
     *         <td>Day in year
     *         <td><a href="#number">Number</a>
     *         <td><code>189</code>
     *     <tr>
     *         <td><code>d</code>
     *         <td>Day in month
     *         <td><a href="#number">Number</a>
     *         <td><code>10</code>
     *     <tr style="background-color: rgb(238, 238, 255);">
     *         <td><code>F</code>
     *         <td>Day of week in month
     *         <td><a href="#number">Number</a>
     *         <td><code>2</code>
     *     <tr>
     *         <td><code>E</code>
     *         <td>Day name in week
     *         <td><a href="#text">Text</a>
     *         <td><code>Tuesday</code>; <code>Tue</code>
     *     <tr style="background-color: rgb(238, 238, 255);">
     *         <td><code>u</code>
     *         <td>Day number of week (1 = Monday, ..., 7 = Sunday)
     *         <td><a href="#number">Number</a>
     *         <td><code>1</code>
     *     <tr>
     *         <td><code>a</code>
     *         <td>Am/pm marker
     *         <td><a href="#text">Text</a>
     *         <td><code>PM</code>
     *     <tr style="background-color: rgb(238, 238, 255);">
     *         <td><code>H</code>
     *         <td>Hour in day (0-23)
     *         <td><a href="#number">Number</a>
     *         <td><code>0</code>
     *     <tr>
     *         <td><code>k</code>
     *         <td>Hour in day (1-24)
     *         <td><a href="#number">Number</a>
     *         <td><code>24</code>
     *     <tr style="background-color: rgb(238, 238, 255);">
     *         <td><code>K</code>
     *         <td>Hour in am/pm (0-11)
     *         <td><a href="#number">Number</a>
     *         <td><code>0</code>
     *     <tr>
     *         <td><code>h</code>
     *         <td>Hour in am/pm (1-12)
     *         <td><a href="#number">Number</a>
     *         <td><code>12</code>
     *     <tr style="background-color: rgb(238, 238, 255);">
     *         <td><code>m</code>
     *         <td>Minute in hour
     *         <td><a href="#number">Number</a>
     *         <td><code>30</code>
     *     <tr>
     *         <td><code>s</code>
     *         <td>Second in minute
     *         <td><a href="#number">Number</a>
     *         <td><code>55</code>
     *     <tr style="background-color: rgb(238, 238, 255);">
     *         <td><code>S</code>
     *         <td>Millisecond
     *         <td><a href="#number">Number</a>
     *         <td><code>978</code>
     *     <tr>
     *         <td><code>z</code>
     *         <td>Time zone
     *         <td><a href="#timezone">General time zone</a>
     *         <td><code>Pacific Standard Time</code>; <code>PST</code>; <code>GMT-08:00</code>
     *     <tr style="background-color: rgb(238, 238, 255);">
     *         <td><code>Z</code>
     *         <td>Time zone
     *         <td><a href="#rfc822timezone">RFC 822 time zone</a>
     *         <td><code>-0800</code>
     *     <tr>
     *         <td><code>X</code>
     *         <td>Time zone
     *         <td><a href="#iso8601timezone">ISO 8601 time zone</a>
     *         <td><code>-08</code>; <code>-0800</code>;  <code>-08:00</code>
     * </table>
     * </blockquote>
     * Pattern letters are usually repeated, as their number determines the
     * exact presentation:
     * <ul>
     * <li><strong><a name="text">Text:</a></strong>
     *     For formatting, if the number of pattern letters is 4 or more,
     *     the full form is used; otherwise a short or abbreviated form
     *     is used if available.
     *     For parsing, both forms are accepted, independent of the number
     *     of pattern letters.<br><br></li>
     * <li><strong><a name="number">Number:</a></strong>
     *     For formatting, the number of pattern letters is the minimum
     *     number of digits, and shorter numbers are zero-padded to this amount.
     *     For parsing, the number of pattern letters is ignored unless
     *     it's needed to separate two adjacent fields.<br><br></li>
     * <li><strong><a name="year">Year:</a></strong>
     *     If the formatter's {@link #getCalendar() Calendar} is the Gregorian
     *     calendar, the following rules are applied.<br>
     *     <ul>
     *     <li>For formatting, if the number of pattern letters is 2, the year
     *         is truncated to 2 digits; otherwise it is interpreted as a
     *         <a href="#number">number</a>.
     *     <li>For parsing, if the number of pattern letters is more than 2,
     *         the year is interpreted literally, regardless of the number of
     *         digits. So using the pattern "MM/dd/yyyy", "01/11/12" parses to
     *         Jan 11, 12 A.D.
     *     <li>For parsing with the abbreviated year pattern ("y" or "yy"),
     *         <code>SimpleDateFormat</code> must interpret the abbreviated year
     *         relative to some century.  It does this by adjusting dates to be
     *         within 80 years before and 20 years after the time the <code>SimpleDateFormat</code>
     *         instance is created. For example, using a pattern of "MM/dd/yy" and a
     *         <code>SimpleDateFormat</code> instance created on Jan 1, 1997,  the string
     *         "01/11/12" would be interpreted as Jan 11, 2012 while the string "05/04/64"
     *         would be interpreted as May 4, 1964.
     *         During parsing, only strings consisting of exactly two digits, as defined by
     *         {@link Character#isDigit(char)}, will be parsed into the default century.
     *         Any other numeric string, such as a one digit string, a three or more digit
     *         string, or a two digit string that isn't all digits (for example, "-1"), is
     *         interpreted literally.  So "01/02/3" or "01/02/003" are parsed, using the
     *         same pattern, as Jan 2, 3 AD.  Likewise, "01/02/-3" is parsed as Jan 2, 4 BC.
     *     </ul>
     *     Otherwise, calendar system specific forms are applied.
     *     For both formatting and parsing, if the number of pattern
     *     letters is 4 or more, a calendar specific {@linkplain
     *     Calendar#LONG long form} is used. Otherwise, a calendar
     *     specific {@linkplain Calendar#SHORT short or abbreviated form}
     *     is used.<br>
     *     <br>
     *     If week year {@code 'Y'} is specified and the {@linkplain
     *     #getCalendar() calendar} doesn't support any <a
     *     href="../util/GregorianCalendar.html#week_year"> week
     *     years</a>, the calendar year ({@code 'y'}) is used instead. The
     *     support of week years can be tested with a call to {@link
     *     DateFormat#getCalendar() getCalendar()}.{@link
     *     java.util.Calendar#isWeekDateSupported()
     *     isWeekDateSupported()}.<br><br></li>
     * <li><strong><a name="month">Month:</a></strong>
     *     If the number of pattern letters is 3 or more, the month is
     *     interpreted as <a href="#text">text</a>; otherwise,
     *     it is interpreted as a <a href="#number">number</a>.<br>
     *     <ul>
     *     <li>Letter <em>M</em> produces context-sensitive month names, such as the
     *         embedded form of names. If a {@code DateFormatSymbols} has been set
     *         explicitly with constructor {@link #SimpleDateFormat(String,
     *         DateFormatSymbols)} or method {@link
     *         #setDateFormatSymbols(DateFormatSymbols)}, the month names given by
     *         the {@code DateFormatSymbols} are used.</li>
     *     <li>Letter <em>L</em> produces the standalone form of month names.</li>
     *     </ul>
     *     <br></li>
     * <li><strong><a name="timezone">General time zone:</a></strong>
     *     Time zones are interpreted as <a href="#text">text</a> if they have
     *     names. For time zones representing a GMT offset value, the
     *     following syntax is used:
     *     <pre>
     *     <a name="GMTOffsetTimeZone"><i>GMTOffsetTimeZone:</i></a>
     *             <code>GMT</code> <i>Sign</i> <i>Hours</i> <code>:</code> <i>Minutes</i>
     *     <i>Sign:</i> one of
     *             <code>+ -</code>
     *     <i>Hours:</i>
     *             <i>Digit</i>
     *             <i>Digit</i> <i>Digit</i>
     *     <i>Minutes:</i>
     *             <i>Digit</i> <i>Digit</i>
     *     <i>Digit:</i> one of
     *             <code>0 1 2 3 4 5 6 7 8 9</code></pre>
     *     <i>Hours</i> must be between 0 and 23, and <i>Minutes</i> must be between
     *     00 and 59. The format is locale independent and digits must be taken
     *     from the Basic Latin block of the Unicode standard.
     *     <p>For parsing, <a href="#rfc822timezone">RFC 822 time zones</a> are also
     *     accepted.<br><br></li>
     * <li><strong><a name="rfc822timezone">RFC 822 time zone:</a></strong>
     *     For formatting, the RFC 822 4-digit time zone format is used:
     *
     *     <pre>
     *     <i>RFC822TimeZone:</i>
     *             <i>Sign</i> <i>TwoDigitHours</i> <i>Minutes</i>
     *     <i>TwoDigitHours:</i>
     *             <i>Digit Digit</i></pre>
     *     <i>TwoDigitHours</i> must be between 00 and 23. Other definitions
     *     are as for <a href="#timezone">general time zones</a>.
     *
     *     <p>For parsing, <a href="#timezone">general time zones</a> are also
     *     accepted.
     * <li><strong><a name="iso8601timezone">ISO 8601 Time zone:</a></strong>
     *     The number of pattern letters designates the format for both formatting
     *     and parsing as follows:
     *     <pre>
     *     <i>ISO8601TimeZone:</i>
     *             <i>OneLetterISO8601TimeZone</i>
     *             <i>TwoLetterISO8601TimeZone</i>
     *             <i>ThreeLetterISO8601TimeZone</i>
     *     <i>OneLetterISO8601TimeZone:</i>
     *             <i>Sign</i> <i>TwoDigitHours</i>
     *             {@code Z}
     *     <i>TwoLetterISO8601TimeZone:</i>
     *             <i>Sign</i> <i>TwoDigitHours</i> <i>Minutes</i>
     *             {@code Z}
     *     <i>ThreeLetterISO8601TimeZone:</i>
     *             <i>Sign</i> <i>TwoDigitHours</i> {@code :} <i>Minutes</i>
     *             {@code Z}</pre>
     *     Other definitions are as for <a href="#timezone">general time zones</a> or
     *     <a href="#rfc822timezone">RFC 822 time zones</a>.
     *
     *     <p>For formatting, if the offset value from GMT is 0, {@code "Z"} is
     *     produced. If the number of pattern letters is 1, any fraction of an hour
     *     is ignored. For example, if the pattern is {@code "X"} and the time zone is
     *     {@code "GMT+05:30"}, {@code "+05"} is produced.
     *
     *     <p>For parsing, {@code "Z"} is parsed as the UTC time zone designator.
     *     <a href="#timezone">General time zones</a> are <em>not</em> accepted.
     *
     *     <p>If the number of pattern letters is 4 or more, {@link
     *     IllegalArgumentException} is thrown when constructing a {@code
     *     SimpleDateFormat} or {@linkplain #applyPattern(String) applying a
     *     pattern}.
     * </ul>
     * <code>SimpleDateFormat</code> also supports <em>localized date and time
     * pattern</em> strings. In these strings, the pattern letters described above
     * may be replaced with other, locale dependent, pattern letters.
     * <code>SimpleDateFormat</code> does not deal with the localization of text
     * other than the pattern letters; that's up to the client of the class.
     *
     * <h4>Examples</h4>
     *
     * The following examples show how date and time patterns are interpreted in
     * the U.S. locale. The given date and time are 2001-07-04 12:08:56 local time
     * in the U.S. Pacific Time time zone.
     * <blockquote>
     * <table border=0 cellspacing=3 cellpadding=0 summary="Examples of date and time patterns interpreted in the U.S. locale">
     *     <tr style="background-color: rgb(204, 204, 255);">
     *         <th align=left>Date and Time Pattern
     *         <th align=left>Result
     *     <tr>
     *         <td><code>"yyyy.MM.dd G 'at' HH:mm:ss z"</code>
     *         <td><code>2001.07.04 AD at 12:08:56 PDT</code>
     *     <tr style="background-color: rgb(238, 238, 255);">
     *         <td><code>"EEE, MMM d, ''yy"</code>
     *         <td><code>Wed, Jul 4, '01</code>
     *     <tr>
     *         <td><code>"h:mm a"</code>
     *         <td><code>12:08 PM</code>
     *     <tr style="background-color: rgb(238, 238, 255);">
     *         <td><code>"hh 'o''clock' a, zzzz"</code>
     *         <td><code>12 o'clock PM, Pacific Daylight Time</code>
     *     <tr>
     *         <td><code>"K:mm a, z"</code>
     *         <td><code>0:08 PM, PDT</code>
     *     <tr style="background-color: rgb(238, 238, 255);">
     *         <td><code>"yyyyy.MMMMM.dd GGG hh:mm aaa"</code>
     *         <td><code>02001.July.04 AD 12:08 PM</code>
     *     <tr>
     *         <td><code>"EEE, d MMM yyyy HH:mm:ss Z"</code>
     *         <td><code>Wed, 4 Jul 2001 12:08:56 -0700</code>
     *     <tr style="background-color: rgb(238, 238, 255);">
     *         <td><code>"yyMMddHHmmssZ"</code>
     *         <td><code>010704120856-0700</code>
     *     <tr>
     *         <td><code>"yyyy-MM-dd'T'HH:mm:ss.SSSZ"</code>
     *         <td><code>2001-07-04T12:08:56.235-0700</code>
     *     <tr style="background-color: rgb(238, 238, 255);">
     *         <td><code>"yyyy-MM-dd'T'HH:mm:ss.SSSXXX"</code>
     *         <td><code>2001-07-04T12:08:56.235-07:00</code>
     *     <tr>
     *         <td><code>"YYYY-'W'ww-u"</code>
     *         <td><code>2001-W27-3</code>
     * </table>
     * </blockquote>
     *
     * <h4><a name="synchronization">Synchronization</a></h4>
     *
     * <p>
     * Date formats are not synchronized.
     * It is recommended to create separate format instances for each thread.
     * If multiple threads access a format concurrently, it must be synchronized
     * externally.
     *
     * @see          <a href="https://docs.oracle.com/javase/tutorial/i18n/format/simpleDateFormat.html">Java Tutorial</a>
     * @see          java.util.Calendar
     * @see          java.util.TimeZone
     * @see          DateFormat
     * @see          DateFormatSymbols
     * @author       Mark Davis, Chen-Lieh Huang, Alan Liu
     */
    public class SimpleDateFormat extends DateFormat {
    
        // the official serial version ID which says cryptically
        // which version we're compatible with
        static final long serialVersionUID = 4774881970558875024L;
    
        // the internal serial version which says which version was written
        // - 0 (default) for version up to JDK 1.1.3
        // - 1 for version from JDK 1.1.4, which includes a new field
        static final int currentSerialVersion = 1;
    
        /**
         * The version of the serialized data on the stream.  Possible values:
         * <ul>
         * <li><b>0</b> or not present on stream: JDK 1.1.3.  This version
         * has no <code>defaultCenturyStart</code> on stream.
         * <li><b>1</b> JDK 1.1.4 or later.  This version adds
         * <code>defaultCenturyStart</code>.
         * </ul>
         * When streaming out this class, the most recent format
         * and the highest allowable <code>serialVersionOnStream</code>
         * is written.
         * @serial
         * @since JDK1.1.4
         */
        private int serialVersionOnStream = currentSerialVersion;
    
        /**
         * The pattern string of this formatter.  This is always a non-localized
         * pattern.  May not be null.  See class documentation for details.
         * @serial
         */
        private String pattern;
    
        /**
         * Saved numberFormat and pattern.
         * @see SimpleDateFormat#checkNegativeNumberExpression
         */
        transient private NumberFormat originalNumberFormat;
        transient private String originalNumberPattern;
    
        /**
         * The minus sign to be used with format and parse.
         */
        transient private char minusSign = '-';
    
        /**
         * True when a negative sign follows a number.
         * (True as default in Arabic.)
         */
        transient private boolean hasFollowingMinusSign = false;
    
        /**
         * True if standalone form needs to be used.
         */
        transient private boolean forceStandaloneForm = false;
    
        /**
         * The compiled pattern.
         */
        transient private char[] compiledPattern;
    
        /**
         * Tags for the compiled pattern.
         */
        private final static int TAG_QUOTE_ASCII_CHAR       = 100;
        private final static int TAG_QUOTE_CHARS            = 101;
    
        /**
         * Locale dependent digit zero.
         * @see #zeroPaddingNumber
         * @see java.text.DecimalFormatSymbols#getZeroDigit
         */
        transient private char zeroDigit;
    
        /**
         * The symbols used by this formatter for week names, month names,
         * etc.  May not be null.
         * @serial
         * @see java.text.DateFormatSymbols
         */
        private DateFormatSymbols formatData;
    
        /**
         * We map dates with two-digit years into the century starting at
         * <code>defaultCenturyStart</code>, which may be any date.  May
         * not be null.
         * @serial
         * @since JDK1.1.4
         */
        private Date defaultCenturyStart;
    
        transient private int defaultCenturyStartYear;
    
        private static final int MILLIS_PER_MINUTE = 60 * 1000;
    
        // For time zones that have no names, use strings GMT+minutes and
        // GMT-minutes. For instance, in France the time zone is GMT+60.
        private static final String GMT = "GMT";
    
        /**
         * Cache NumberFormat instances with Locale key.
         */
        private static final ConcurrentMap<Locale, NumberFormat> cachedNumberFormatData
            = new ConcurrentHashMap<>(3);
    
        /**
         * The Locale used to instantiate this
         * <code>SimpleDateFormat</code>. The value may be null if this object
         * has been created by an older <code>SimpleDateFormat</code> and
         * deserialized.
         *
         * @serial
         * @since 1.6
         */
        private Locale locale;
    
        /**
         * Indicates whether this <code>SimpleDateFormat</code> should use
         * the DateFormatSymbols. If true, the format and parse methods
         * use the DateFormatSymbols values. If false, the format and
         * parse methods call Calendar.getDisplayName or
         * Calendar.getDisplayNames.
         */
        transient boolean useDateFormatSymbols;
    
        /**
         * Constructs a <code>SimpleDateFormat</code> using the default pattern and
         * date format symbols for the default
         * {@link java.util.Locale.Category#FORMAT FORMAT} locale.
         * <b>Note:</b> This constructor may not support all locales.
         * For full coverage, use the factory methods in the {@link DateFormat}
         * class.
         */
        public SimpleDateFormat() {
            this("", Locale.getDefault(Locale.Category.FORMAT));
            applyPatternImpl(LocaleProviderAdapter.getResourceBundleBased().getLocaleResources(locale)
                             .getDateTimePattern(SHORT, SHORT, calendar));
        }
    
        /**
         * Constructs a <code>SimpleDateFormat</code> using the given pattern and
         * the default date format symbols for the default
         * {@link java.util.Locale.Category#FORMAT FORMAT} locale.
         * <b>Note:</b> This constructor may not support all locales.
         * For full coverage, use the factory methods in the {@link DateFormat}
         * class.
         * <p>This is equivalent to calling
         * {@link #SimpleDateFormat(String, Locale)
         *     SimpleDateFormat(pattern, Locale.getDefault(Locale.Category.FORMAT))}.
         *
         * @see java.util.Locale#getDefault(java.util.Locale.Category)
         * @see java.util.Locale.Category#FORMAT
         * @param pattern the pattern describing the date and time format
         * @exception NullPointerException if the given pattern is null
         * @exception IllegalArgumentException if the given pattern is invalid
         */
        public SimpleDateFormat(String pattern)
        {
            this(pattern, Locale.getDefault(Locale.Category.FORMAT));
        }
    
        /**
         * Constructs a <code>SimpleDateFormat</code> using the given pattern and
         * the default date format symbols for the given locale.
         * <b>Note:</b> This constructor may not support all locales.
         * For full coverage, use the factory methods in the {@link DateFormat}
         * class.
         *
         * @param pattern the pattern describing the date and time format
         * @param locale the locale whose date format symbols should be used
         * @exception NullPointerException if the given pattern or locale is null
         * @exception IllegalArgumentException if the given pattern is invalid
         */
        public SimpleDateFormat(String pattern, Locale locale)
        {
            if (pattern == null || locale == null) {
                throw new NullPointerException();
            }
    
            initializeCalendar(locale);
            this.pattern = pattern;
            this.formatData = DateFormatSymbols.getInstanceRef(locale);
            this.locale = locale;
            initialize(locale);
        }
    
        /**
         * Constructs a <code>SimpleDateFormat</code> using the given pattern and
         * date format symbols.
         *
         * @param pattern the pattern describing the date and time format
         * @param formatSymbols the date format symbols to be used for formatting
         * @exception NullPointerException if the given pattern or formatSymbols is null
         * @exception IllegalArgumentException if the given pattern is invalid
         */
        public SimpleDateFormat(String pattern, DateFormatSymbols formatSymbols)
        {
            if (pattern == null || formatSymbols == null) {
                throw new NullPointerException();
            }
    
            this.pattern = pattern;
            this.formatData = (DateFormatSymbols) formatSymbols.clone();
            this.locale = Locale.getDefault(Locale.Category.FORMAT);
            initializeCalendar(this.locale);
            initialize(this.locale);
            useDateFormatSymbols = true;
        }
    
        /* Initialize compiledPattern and numberFormat fields */
        private void initialize(Locale loc) {
            // Verify and compile the given pattern.
            compiledPattern = compile(pattern);
    
            /* try the cache first */
            numberFormat = cachedNumberFormatData.get(loc);
            if (numberFormat == null) { /* cache miss */
                numberFormat = NumberFormat.getIntegerInstance(loc);
                numberFormat.setGroupingUsed(false);
    
                /* update cache */
                cachedNumberFormatData.putIfAbsent(loc, numberFormat);
            }
            numberFormat = (NumberFormat) numberFormat.clone();
    
            initializeDefaultCentury();
        }
    
        private void initializeCalendar(Locale loc) {
            if (calendar == null) {
                assert loc != null;
                // The format object must be constructed using the symbols for this zone.
                // However, the calendar should use the current default TimeZone.
                // If this is not contained in the locale zone strings, then the zone
                // will be formatted using generic GMT+/-H:MM nomenclature.
                calendar = Calendar.getInstance(TimeZone.getDefault(), loc);
            }
        }
    
        /**
         * Returns the compiled form of the given pattern. The syntax of
         * the compiled pattern is:
         * <blockquote>
         * CompiledPattern:
         *     EntryList
         * EntryList:
         *     Entry
         *     EntryList Entry
         * Entry:
         *     TagField
         *     TagField data
         * TagField:
         *     Tag Length
         *     TaggedData
         * Tag:
         *     pattern_char_index
         *     TAG_QUOTE_CHARS
         * Length:
         *     short_length
         *     long_length
         * TaggedData:
         *     TAG_QUOTE_ASCII_CHAR ascii_char
         *
         * </blockquote>
         *
         * where `short_length' is an 8-bit unsigned integer between 0 and
         * 254.  `long_length' is a sequence of an 8-bit integer 255 and a
         * 32-bit signed integer value which is split into upper and lower
         * 16-bit fields in two char's. `pattern_char_index' is an 8-bit
         * integer between 0 and 18. `ascii_char' is an 7-bit ASCII
         * character value. `data' depends on its Tag value.
         * <p>
         * If Length is short_length, Tag and short_length are packed in a
         * single char, as illustrated below.
         * <blockquote>
         *     char[0] = (Tag << 8) | short_length;
         * </blockquote>
         *
         * If Length is long_length, Tag and 255 are packed in the first
         * char and a 32-bit integer, as illustrated below.
         * <blockquote>
         *     char[0] = (Tag << 8) | 255;
         *     char[1] = (char) (long_length >>> 16);
         *     char[2] = (char) (long_length & 0xffff);
         * </blockquote>
         * <p>
         * If Tag is a pattern_char_index, its Length is the number of
         * pattern characters. For example, if the given pattern is
         * "yyyy", Tag is 1 and Length is 4, followed by no data.
         * <p>
         * If Tag is TAG_QUOTE_CHARS, its Length is the number of char's
         * following the TagField. For example, if the given pattern is
         * "'o''clock'", Length is 7 followed by a char sequence of
         * <code>o&nbs;'&nbs;c&nbs;l&nbs;o&nbs;c&nbs;k</code>.
         * <p>
         * TAG_QUOTE_ASCII_CHAR is a special tag and has an ASCII
         * character in place of Length. For example, if the given pattern
         * is "'o'", the TaggedData entry is
         * <code>((TAG_QUOTE_ASCII_CHAR&nbs;<<&nbs;8)&nbs;|&nbs;'o')</code>.
         *
         * @exception NullPointerException if the given pattern is null
         * @exception IllegalArgumentException if the given pattern is invalid
         */
        private char[] compile(String pattern) {
            int length = pattern.length();
            boolean inQuote = false;
            StringBuilder compiledCode = new StringBuilder(length * 2);
            StringBuilder tmpBuffer = null;
            int count = 0, tagcount = 0;
            int lastTag = -1, prevTag = -1;
    
            for (int i = 0; i < length; i++) {
                char c = pattern.charAt(i);
    
                if (c == '\'') {
                    // '' is treated as a single quote regardless of being
                    // in a quoted section.
                    if ((i + 1) < length) {
                        c = pattern.charAt(i + 1);
                        if (c == '\'') {
                            i++;
                            if (count != 0) {
                                encode(lastTag, count, compiledCode);
                                tagcount++;
                                prevTag = lastTag;
                                lastTag = -1;
                                count = 0;
                            }
                            if (inQuote) {
                                tmpBuffer.append(c);
                            } else {
                                compiledCode.append((char)(TAG_QUOTE_ASCII_CHAR << 8 | c));
                            }
                            continue;
                        }
                    }
                    if (!inQuote) {
                        if (count != 0) {
                            encode(lastTag, count, compiledCode);
                            tagcount++;
                            prevTag = lastTag;
                            lastTag = -1;
                            count = 0;
                        }
                        if (tmpBuffer == null) {
                            tmpBuffer = new StringBuilder(length);
                        } else {
                            tmpBuffer.setLength(0);
                        }
                        inQuote = true;
                    } else {
                        int len = tmpBuffer.length();
                        if (len == 1) {
                            char ch = tmpBuffer.charAt(0);
                            if (ch < 128) {
                                compiledCode.append((char)(TAG_QUOTE_ASCII_CHAR << 8 | ch));
                            } else {
                                compiledCode.append((char)(TAG_QUOTE_CHARS << 8 | 1));
                                compiledCode.append(ch);
                            }
                        } else {
                            encode(TAG_QUOTE_CHARS, len, compiledCode);
                            compiledCode.append(tmpBuffer);
                        }
                        inQuote = false;
                    }
                    continue;
                }
                if (inQuote) {
                    tmpBuffer.append(c);
                    continue;
                }
                if (!(c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z')) {
                    if (count != 0) {
                        encode(lastTag, count, compiledCode);
                        tagcount++;
                        prevTag = lastTag;
                        lastTag = -1;
                        count = 0;
                    }
                    if (c < 128) {
                        // In most cases, c would be a delimiter, such as ':'.
                        compiledCode.append((char)(TAG_QUOTE_ASCII_CHAR << 8 | c));
                    } else {
                        // Take any contiguous non-ASCII alphabet characters and
                        // put them in a single TAG_QUOTE_CHARS.
                        int j;
                        for (j = i + 1; j < length; j++) {
                            char d = pattern.charAt(j);
                            if (d == '\'' || (d >= 'a' && d <= 'z' || d >= 'A' && d <= 'Z')) {
                                break;
                            }
                        }
                        compiledCode.append((char)(TAG_QUOTE_CHARS << 8 | (j - i)));
                        for (; i < j; i++) {
                            compiledCode.append(pattern.charAt(i));
                        }
                        i--;
                    }
                    continue;
                }
    
                int tag;
                if ((tag = DateFormatSymbols.patternChars.indexOf(c)) == -1) {
                    throw new IllegalArgumentException("Illegal pattern character " +
                                                       "'" + c + "'");
                }
                if (lastTag == -1 || lastTag == tag) {
                    lastTag = tag;
                    count++;
                    continue;
                }
                encode(lastTag, count, compiledCode);
                tagcount++;
                prevTag = lastTag;
                lastTag = tag;
                count = 1;
            }
    
            if (inQuote) {
                throw new IllegalArgumentException("Unterminated quote");
            }
    
            if (count != 0) {
                encode(lastTag, count, compiledCode);
                tagcount++;
                prevTag = lastTag;
            }
    
            forceStandaloneForm = (tagcount == 1 && prevTag == PATTERN_MONTH);
    
            // Copy the compiled pattern to a char array
            int len = compiledCode.length();
            char[] r = new char[len];
            compiledCode.getChars(0, len, r, 0);
            return r;
        }
    
        /**
         * Encodes the given tag and length and puts encoded char(s) into buffer.
         */
        private static void encode(int tag, int length, StringBuilder buffer) {
            if (tag == PATTERN_ISO_ZONE && length >= 4) {
                throw new IllegalArgumentException("invalid ISO 8601 format: length=" + length);
            }
            if (length < 255) {
                buffer.append((char)(tag << 8 | length));
            } else {
                buffer.append((char)((tag << 8) | 0xff));
                buffer.append((char)(length >>> 16));
                buffer.append((char)(length & 0xffff));
            }
        }
    
        /* Initialize the fields we use to disambiguate ambiguous years. Separate
         * so we can call it from readObject().
         */
        private void initializeDefaultCentury() {
            calendar.setTimeInMillis(System.currentTimeMillis());
            calendar.add( Calendar.YEAR, -80 );
            parseAmbiguousDatesAsAfter(calendar.getTime());
        }
    
        /* Define one-century window into which to disambiguate dates using
         * two-digit years.
         */
        private void parseAmbiguousDatesAsAfter(Date startDate) {
            defaultCenturyStart = startDate;
            calendar.setTime(startDate);
            defaultCenturyStartYear = calendar.get(Calendar.YEAR);
        }
    
        /**
         * Sets the 100-year period 2-digit years will be interpreted as being in
         * to begin on the date the user specifies.
         *
         * @param startDate During parsing, two digit years will be placed in the range
         * <code>startDate</code> to <code>startDate + 100 years</code>.
         * @see #get2DigitYearStart
         * @since 1.2
         */
        public void set2DigitYearStart(Date startDate) {
            parseAmbiguousDatesAsAfter(new Date(startDate.getTime()));
        }
    
        /**
         * Returns the beginning date of the 100-year period 2-digit years are interpreted
         * as being within.
         *
         * @return the start of the 100-year period into which two digit years are
         * parsed
         * @see #set2DigitYearStart
         * @since 1.2
         */
        public Date get2DigitYearStart() {
            return (Date) defaultCenturyStart.clone();
        }
    
        /**
         * Formats the given <code>Date</code> into a date/time string and appends
         * the result to the given <code>StringBuffer</code>.
         *
         * @param date the date-time value to be formatted into a date-time string.
         * @param toAppendTo where the new date-time text is to be appended.
         * @param pos the formatting position. On input: an alignment field,
         * if desired. On output: the offsets of the alignment field.
         * @return the formatted date-time string.
         * @exception NullPointerException if the given {@code date} is {@code null}.
         */
        @Override
        public StringBuffer format(Date date, StringBuffer toAppendTo,
                                   FieldPosition pos)
        {
            pos.beginIndex = pos.endIndex = 0;
            return format(date, toAppendTo, pos.getFieldDelegate());
        }
    
        // Called from Format after creating a FieldDelegate
        private StringBuffer format(Date date, StringBuffer toAppendTo,
                                    FieldDelegate delegate) {
            // Convert input date to time field list
            calendar.setTime(date);
    
            boolean useDateFormatSymbols = useDateFormatSymbols();
    
            for (int i = 0; i < compiledPattern.length; ) {
                int tag = compiledPattern[i] >>> 8;
                int count = compiledPattern[i++] & 0xff;
                if (count == 255) {
                    count = compiledPattern[i++] << 16;
                    count |= compiledPattern[i++];
                }
    
                switch (tag) {
                case TAG_QUOTE_ASCII_CHAR:
                    toAppendTo.append((char)count);
                    break;
    
                case TAG_QUOTE_CHARS:
                    toAppendTo.append(compiledPattern, i, count);
                    i += count;
                    break;
    
                default:
                    subFormat(tag, count, delegate, toAppendTo, useDateFormatSymbols);
                    break;
                }
            }
            return toAppendTo;
        }
    
        /**
         * Formats an Object producing an <code>AttributedCharacterIterator</code>.
         * You can use the returned <code>AttributedCharacterIterator</code>
         * to build the resulting String, as well as to determine information
         * about the resulting String.
         * <p>
         * Each attribute key of the AttributedCharacterIterator will be of type
         * <code>DateFormat.Field</code>, with the corresponding attribute value
         * being the same as the attribute key.
         *
         * @exception NullPointerException if obj is null.
         * @exception IllegalArgumentException if the Format cannot format the
         *            given object, or if the Format's pattern string is invalid.
         * @param obj The object to format
         * @return AttributedCharacterIterator describing the formatted value.
         * @since 1.4
         */
        @Override
        public AttributedCharacterIterator formatToCharacterIterator(Object obj) {
            StringBuffer sb = new StringBuffer();
            CharacterIteratorFieldDelegate delegate = new
                             CharacterIteratorFieldDelegate();
    
            if (obj instanceof Date) {
                format((Date)obj, sb, delegate);
            }
            else if (obj instanceof Number) {
                format(new Date(((Number)obj).longValue()), sb, delegate);
            }
            else if (obj == null) {
                throw new NullPointerException(
                       "formatToCharacterIterator must be passed non-null object");
            }
            else {
                throw new IllegalArgumentException(
                                 "Cannot format given Object as a Date");
            }
            return delegate.getIterator(sb.toString());
        }
    
        // Map index into pattern character string to Calendar field number
        private static final int[] PATTERN_INDEX_TO_CALENDAR_FIELD = {
            Calendar.ERA,
            Calendar.YEAR,
            Calendar.MONTH,
            Calendar.DATE,
            Calendar.HOUR_OF_DAY,
            Calendar.HOUR_OF_DAY,
            Calendar.MINUTE,
            Calendar.SECOND,
            Calendar.MILLISECOND,
            Calendar.DAY_OF_WEEK,
            Calendar.DAY_OF_YEAR,
            Calendar.DAY_OF_WEEK_IN_MONTH,
            Calendar.WEEK_OF_YEAR,
            Calendar.WEEK_OF_MONTH,
            Calendar.AM_PM,
            Calendar.HOUR,
            Calendar.HOUR,
            Calendar.ZONE_OFFSET,
            Calendar.ZONE_OFFSET,
            CalendarBuilder.WEEK_YEAR,         // Pseudo Calendar field
            CalendarBuilder.ISO_DAY_OF_WEEK,   // Pseudo Calendar field
            Calendar.ZONE_OFFSET,
            Calendar.MONTH
        };
    
        // Map index into pattern character string to DateFormat field number
        private static final int[] PATTERN_INDEX_TO_DATE_FORMAT_FIELD = {
            DateFormat.ERA_FIELD,
            DateFormat.YEAR_FIELD,
            DateFormat.MONTH_FIELD,
            DateFormat.DATE_FIELD,
            DateFormat.HOUR_OF_DAY1_FIELD,
            DateFormat.HOUR_OF_DAY0_FIELD,
            DateFormat.MINUTE_FIELD,
            DateFormat.SECOND_FIELD,
            DateFormat.MILLISECOND_FIELD,
            DateFormat.DAY_OF_WEEK_FIELD,
            DateFormat.DAY_OF_YEAR_FIELD,
            DateFormat.DAY_OF_WEEK_IN_MONTH_FIELD,
            DateFormat.WEEK_OF_YEAR_FIELD,
            DateFormat.WEEK_OF_MONTH_FIELD,
            DateFormat.AM_PM_FIELD,
            DateFormat.HOUR1_FIELD,
            DateFormat.HOUR0_FIELD,
            DateFormat.TIMEZONE_FIELD,
            DateFormat.TIMEZONE_FIELD,
            DateFormat.YEAR_FIELD,
            DateFormat.DAY_OF_WEEK_FIELD,
            DateFormat.TIMEZONE_FIELD,
            DateFormat.MONTH_FIELD
        };
    
        // Maps from DecimalFormatSymbols index to Field constant
        private static final Field[] PATTERN_INDEX_TO_DATE_FORMAT_FIELD_ID = {
            Field.ERA,
            Field.YEAR,
            Field.MONTH,
            Field.DAY_OF_MONTH,
            Field.HOUR_OF_DAY1,
            Field.HOUR_OF_DAY0,
            Field.MINUTE,
            Field.SECOND,
            Field.MILLISECOND,
            Field.DAY_OF_WEEK,
            Field.DAY_OF_YEAR,
            Field.DAY_OF_WEEK_IN_MONTH,
            Field.WEEK_OF_YEAR,
            Field.WEEK_OF_MONTH,
            Field.AM_PM,
            Field.HOUR1,
            Field.HOUR0,
            Field.TIME_ZONE,
            Field.TIME_ZONE,
            Field.YEAR,
            Field.DAY_OF_WEEK,
            Field.TIME_ZONE,
            Field.MONTH
        };
    
        /**
         * Private member function that does the real date/time formatting.
         */
        private void subFormat(int patternCharIndex, int count,
                               FieldDelegate delegate, StringBuffer buffer,
                               boolean useDateFormatSymbols)
        {
            int     maxIntCount = Integer.MAX_VALUE;
            String  current = null;
            int     beginOffset = buffer.length();
    
            int field = PATTERN_INDEX_TO_CALENDAR_FIELD[patternCharIndex];
            int value;
            if (field == CalendarBuilder.WEEK_YEAR) {
                if (calendar.isWeekDateSupported()) {
                    value = calendar.getWeekYear();
                } else {
                    // use calendar year 'y' instead
                    patternCharIndex = PATTERN_YEAR;
                    field = PATTERN_INDEX_TO_CALENDAR_FIELD[patternCharIndex];
                    value = calendar.get(field);
                }
            } else if (field == CalendarBuilder.ISO_DAY_OF_WEEK) {
                value = CalendarBuilder.toISODayOfWeek(calendar.get(Calendar.DAY_OF_WEEK));
            } else {
                value = calendar.get(field);
            }
    
            int style = (count >= 4) ? Calendar.LONG : Calendar.SHORT;
            if (!useDateFormatSymbols && field < Calendar.ZONE_OFFSET
                && patternCharIndex != PATTERN_MONTH_STANDALONE) {
                current = calendar.getDisplayName(field, style, locale);
            }
    
            // Note: zeroPaddingNumber() assumes that maxDigits is either
            // 2 or maxIntCount. If we make any changes to this,
            // zeroPaddingNumber() must be fixed.
    
            switch (patternCharIndex) {
            case PATTERN_ERA: // 'G'
                if (useDateFormatSymbols) {
                    String[] eras = formatData.getEras();
                    if (value < eras.length) {
                        current = eras[value];
                    }
                }
                if (current == null) {
                    current = "";
                }
                break;
    
            case PATTERN_WEEK_YEAR: // 'Y'
            case PATTERN_YEAR:      // 'y'
                if (calendar instanceof GregorianCalendar) {
                    if (count != 2) {
                        zeroPaddingNumber(value, count, maxIntCount, buffer);
                    } else {
                        zeroPaddingNumber(value, 2, 2, buffer);
                    } // clip 1996 to 96
                } else {
                    if (current == null) {
                        zeroPaddingNumber(value, style == Calendar.LONG ? 1 : count,
                                          maxIntCount, buffer);
                    }
                }
                break;
    
            case PATTERN_MONTH:            // 'M' (context seinsive)
                if (useDateFormatSymbols) {
                    String[] months;
                    if (count >= 4) {
                        months = formatData.getMonths();
                        current = months[value];
                    } else if (count == 3) {
                        months = formatData.getShortMonths();
                        current = months[value];
                    }
                } else {
                    if (count < 3) {
                        current = null;
                    } else if (forceStandaloneForm) {
                        current = calendar.getDisplayName(field, style | 0x8000, locale);
                        if (current == null) {
                            current = calendar.getDisplayName(field, style, locale);
                        }
                    }
                }
                if (current == null) {
                    zeroPaddingNumber(value+1, count, maxIntCount, buffer);
                }
                break;
    
            case PATTERN_MONTH_STANDALONE: // 'L'
                assert current == null;
                if (locale == null) {
                    String[] months;
                    if (count >= 4) {
                        months = formatData.getMonths();
                        current = months[value];
                    } else if (count == 3) {
                        months = formatData.getShortMonths();
                        current = months[value];
                    }
                } else {
                    if (count >= 3) {
                        current = calendar.getDisplayName(field, style | 0x8000, locale);
                    }
                }
                if (current == null) {
                    zeroPaddingNumber(value+1, count, maxIntCount, buffer);
                }
                break;
    
            case PATTERN_HOUR_OF_DAY1: // 'k' 1-based.  eg, 23:59 + 1 hour =>> 24:59
                if (current == null) {
                    if (value == 0) {
                        zeroPaddingNumber(calendar.getMaximum(Calendar.HOUR_OF_DAY) + 1,
                                          count, maxIntCount, buffer);
                    } else {
                        zeroPaddingNumber(value, count, maxIntCount, buffer);
                    }
                }
                break;
    
            case PATTERN_DAY_OF_WEEK: // 'E'
                if (useDateFormatSymbols) {
                    String[] weekdays;
                    if (count >= 4) {
                        weekdays = formatData.getWeekdays();
                        current = weekdays[value];
                    } else { // count < 4, use abbreviated form if exists
                        weekdays = formatData.getShortWeekdays();
                        current = weekdays[value];
                    }
                }
                break;
    
            case PATTERN_AM_PM:    // 'a'
                if (useDateFormatSymbols) {
                    String[] ampm = formatData.getAmPmStrings();
                    current = ampm[value];
                }
                break;
    
            case PATTERN_HOUR1:    // 'h' 1-based.  eg, 11PM + 1 hour =>> 12 AM
                if (current == null) {
                    if (value == 0) {
                        zeroPaddingNumber(calendar.getLeastMaximum(Calendar.HOUR) + 1,
                                          count, maxIntCount, buffer);
                    } else {
                        zeroPaddingNumber(value, count, maxIntCount, buffer);
                    }
                }
                break;
    
            case PATTERN_ZONE_NAME: // 'z'
                if (current == null) {
                    if (formatData.locale == null || formatData.isZoneStringsSet) {
                        int zoneIndex =
                            formatData.getZoneIndex(calendar.getTimeZone().getID());
                        if (zoneIndex == -1) {
                            value = calendar.get(Calendar.ZONE_OFFSET) +
                                calendar.get(Calendar.DST_OFFSET);
                            buffer.append(ZoneInfoFile.toCustomID(value));
                        } else {
                            int index = (calendar.get(Calendar.DST_OFFSET) == 0) ? 1: 3;
                            if (count < 4) {
                                // Use the short name
                                index++;
                            }
                            String[][] zoneStrings = formatData.getZoneStringsWrapper();
                            buffer.append(zoneStrings[zoneIndex][index]);
                        }
                    } else {
                        TimeZone tz = calendar.getTimeZone();
                        boolean daylight = (calendar.get(Calendar.DST_OFFSET) != 0);
                        int tzstyle = (count < 4 ? TimeZone.SHORT : TimeZone.LONG);
                        buffer.append(tz.getDisplayName(daylight, tzstyle, formatData.locale));
                    }
                }
                break;
    
            case PATTERN_ZONE_VALUE: // 'Z' ("-/+hhmm" form)
                value = (calendar.get(Calendar.ZONE_OFFSET) +
                         calendar.get(Calendar.DST_OFFSET)) / 60000;
    
                int width = 4;
                if (value >= 0) {
                    buffer.append('+');
                } else {
                    width++;
                }
    
                int num = (value / 60) * 100 + (value % 60);
                CalendarUtils.sprintf0d(buffer, num, width);
                break;
    
            case PATTERN_ISO_ZONE:   // 'X'
                value = calendar.get(Calendar.ZONE_OFFSET)
                        + calendar.get(Calendar.DST_OFFSET);
    
                if (value == 0) {
                    buffer.append('Z');
                    break;
                }
    
                value /=  60000;
                if (value >= 0) {
                    buffer.append('+');
                } else {
                    buffer.append('-');
                    value = -value;
                }
    
                CalendarUtils.sprintf0d(buffer, value / 60, 2);
                if (count == 1) {
                    break;
                }
    
                if (count == 3) {
                    buffer.append(':');
                }
                CalendarUtils.sprintf0d(buffer, value % 60, 2);
                break;
    
            default:
         // case PATTERN_DAY_OF_MONTH:         // 'd'
         // case PATTERN_HOUR_OF_DAY0:         // 'H' 0-based.  eg, 23:59 + 1 hour =>> 00:59
         // case PATTERN_MINUTE:               // 'm'
         // case PATTERN_SECOND:               // 's'
         // case PATTERN_MILLISECOND:          // 'S'
         // case PATTERN_DAY_OF_YEAR:          // 'D'
         // case PATTERN_DAY_OF_WEEK_IN_MONTH: // 'F'
         // case PATTERN_WEEK_OF_YEAR:         // 'w'
         // case PATTERN_WEEK_OF_MONTH:        // 'W'
         // case PATTERN_HOUR0:                // 'K' eg, 11PM + 1 hour =>> 0 AM
         // case PATTERN_ISO_DAY_OF_WEEK:      // 'u' pseudo field, Monday = 1, ..., Sunday = 7
                if (current == null) {
                    zeroPaddingNumber(value, count, maxIntCount, buffer);
                }
                break;
            } // switch (patternCharIndex)
    
            if (current != null) {
                buffer.append(current);
            }
    
            int fieldID = PATTERN_INDEX_TO_DATE_FORMAT_FIELD[patternCharIndex];
            Field f = PATTERN_INDEX_TO_DATE_FORMAT_FIELD_ID[patternCharIndex];
    
            delegate.formatted(fieldID, f, f, beginOffset, buffer.length(), buffer);
        }
    
        /**
         * Formats a number with the specified minimum and maximum number of digits.
         */
        private void zeroPaddingNumber(int value, int minDigits, int maxDigits, StringBuffer buffer)
        {
            // Optimization for 1, 2 and 4 digit numbers. This should
            // cover most cases of formatting date/time related items.
            // Note: This optimization code assumes that maxDigits is
            // either 2 or Integer.MAX_VALUE (maxIntCount in format()).
            try {
                if (zeroDigit == 0) {
                    zeroDigit = ((DecimalFormat)numberFormat).getDecimalFormatSymbols().getZeroDigit();
                }
                if (value >= 0) {
                    if (value < 100 && minDigits >= 1 && minDigits <= 2) {
                        if (value < 10) {
                            if (minDigits == 2) {
                                buffer.append(zeroDigit);
                            }
                            buffer.append((char)(zeroDigit + value));
                        } else {
                            buffer.append((char)(zeroDigit + value / 10));
                            buffer.append((char)(zeroDigit + value % 10));
                        }
                        return;
                    } else if (value >= 1000 && value < 10000) {
                        if (minDigits == 4) {
                            buffer.append((char)(zeroDigit + value / 1000));
                            value %= 1000;
                            buffer.append((char)(zeroDigit + value / 100));
                            value %= 100;
                            buffer.append((char)(zeroDigit + value / 10));
                            buffer.append((char)(zeroDigit + value % 10));
                            return;
                        }
                        if (minDigits == 2 && maxDigits == 2) {
                            zeroPaddingNumber(value % 100, 2, 2, buffer);
                            return;
                        }
                    }
                }
            } catch (Exception e) {
            }
    
            numberFormat.setMinimumIntegerDigits(minDigits);
            numberFormat.setMaximumIntegerDigits(maxDigits);
            numberFormat.format((long)value, buffer, DontCareFieldPosition.INSTANCE);
        }
    
    
        /**
         * Parses text from a string to produce a <code>Date</code>.
         * <p>
         * The method attempts to parse text starting at the index given by
         * <code>pos</code>.
         * If parsing succeeds, then the index of <code>pos</code> is updated
         * to the index after the last character used (parsing does not necessarily
         * use all characters up to the end of the string), and the parsed
         * date is returned. The updated <code>pos</code> can be used to
         * indicate the starting point for the next call to this method.
         * If an error occurs, then the index of <code>pos</code> is not
         * changed, the error index of <code>pos</code> is set to the index of
         * the character where the error occurred, and null is returned.
         *
         * <p>This parsing operation uses the {@link DateFormat#calendar
         * calendar} to produce a {@code Date}. All of the {@code
         * calendar}'s date-time fields are {@linkplain Calendar#clear()
         * cleared} before parsing, and the {@code calendar}'s default
         * values of the date-time fields are used for any missing
         * date-time information. For example, the year value of the
         * parsed {@code Date} is 1970 with {@link GregorianCalendar} if
         * no year value is given from the parsing operation.  The {@code
         * TimeZone} value may be overwritten, depending on the given
         * pattern and the time zone value in {@code text}. Any {@code
         * TimeZone} value that has previously been set by a call to
         * {@link #setTimeZone(java.util.TimeZone) setTimeZone} may need
         * to be restored for further operations.
         *
         * @param text  A <code>String</code>, part of which should be parsed.
         * @param pos   A <code>ParsePosition</code> object with index and error
         *              index information as described above.
         * @return A <code>Date</code> parsed from the string. In case of
         *         error, returns null.
         * @exception NullPointerException if <code>text</code> or <code>pos</code> is null.
         */
        @Override
        public Date parse(String text, ParsePosition pos)
        {
            checkNegativeNumberExpression();
    
            int start = pos.index;
            int oldStart = start;
            int textLength = text.length();
    
            boolean[] ambiguousYear = {false};
    
            CalendarBuilder calb = new CalendarBuilder();
    
            for (int i = 0; i < compiledPattern.length; ) {
                int tag = compiledPattern[i] >>> 8;
                int count = compiledPattern[i++] & 0xff;
                if (count == 255) {
                    count = compiledPattern[i++] << 16;
                    count |= compiledPattern[i++];
                }
    
                switch (tag) {
                case TAG_QUOTE_ASCII_CHAR:
                    if (start >= textLength || text.charAt(start) != (char)count) {
                        pos.index = oldStart;
                        pos.errorIndex = start;
                        return null;
                    }
                    start++;
                    break;
    
                case TAG_QUOTE_CHARS:
                    while (count-- > 0) {
                        if (start >= textLength || text.charAt(start) != compiledPattern[i++]) {
                            pos.index = oldStart;
                            pos.errorIndex = start;
                            return null;
                        }
                        start++;
                    }
                    break;
    
                default:
                    // Peek the next pattern to determine if we need to
                    // obey the number of pattern letters for
                    // parsing. It's required when parsing contiguous
                    // digit text (e.g., "20010704") with a pattern which
                    // has no delimiters between fields, like "yyyyMMdd".
                    boolean obeyCount = false;
    
                    // In Arabic, a minus sign for a negative number is put after
                    // the number. Even in another locale, a minus sign can be
                    // put after a number using DateFormat.setNumberFormat().
                    // If both the minus sign and the field-delimiter are '-',
                    // subParse() needs to determine whether a '-' after a number
                    // in the given text is a delimiter or is a minus sign for the
                    // preceding number. We give subParse() a clue based on the
                    // information in compiledPattern.
                    boolean useFollowingMinusSignAsDelimiter = false;
    
                    if (i < compiledPattern.length) {
                        int nextTag = compiledPattern[i] >>> 8;
                        if (!(nextTag == TAG_QUOTE_ASCII_CHAR ||
                              nextTag == TAG_QUOTE_CHARS)) {
                            obeyCount = true;
                        }
    
                        if (hasFollowingMinusSign &&
                            (nextTag == TAG_QUOTE_ASCII_CHAR ||
                             nextTag == TAG_QUOTE_CHARS)) {
                            int c;
                            if (nextTag == TAG_QUOTE_ASCII_CHAR) {
                                c = compiledPattern[i] & 0xff;
                            } else {
                                c = compiledPattern[i+1];
                            }
    
                            if (c == minusSign) {
                                useFollowingMinusSignAsDelimiter = true;
                            }
                        }
                    }
                    start = subParse(text, start, tag, count, obeyCount,
                                     ambiguousYear, pos,
                                     useFollowingMinusSignAsDelimiter, calb);
                    if (start < 0) {
                        pos.index = oldStart;
                        return null;
                    }
                }
            }
    
            // At this point the fields of Calendar have been set.  Calendar
            // will fill in default values for missing fields when the time
            // is computed.
    
            pos.index = start;
    
            Date parsedDate;
            try {
                parsedDate = calb.establish(calendar).getTime();
                // If the year value is ambiguous,
                // then the two-digit year == the default start year
                if (ambiguousYear[0]) {
                    if (parsedDate.before(defaultCenturyStart)) {
                        parsedDate = calb.addYear(100).establish(calendar).getTime();
                    }
                }
            }
            // An IllegalArgumentException will be thrown by Calendar.getTime()
            // if any fields are out of range, e.g., MONTH == 17.
            catch (IllegalArgumentException e) {
                pos.errorIndex = start;
                pos.index = oldStart;
                return null;
            }
    
            return parsedDate;
        }
    
        /**
         * Private code-size reduction function used by subParse.
         * @param text the time text being parsed.
         * @param start where to start parsing.
         * @param field the date field being parsed.
         * @param data the string array to parsed.
         * @return the new start position if matching succeeded; a negative number
         * indicating matching failure, otherwise.
         */
        private int matchString(String text, int start, int field, String[] data, CalendarBuilder calb)
        {
            int i = 0;
            int count = data.length;
    
            if (field == Calendar.DAY_OF_WEEK) {
                i = 1;
            }
    
            // There may be multiple strings in the data[] array which begin with
            // the same prefix (e.g., Cerven and Cervenec (June and July) in Czech).
            // We keep track of the longest match, and return that.  Note that this
            // unfortunately requires us to test all array elements.
            int bestMatchLength = 0, bestMatch = -1;
            for (; i<count; ++i)
            {
                int length = data[i].length();
                // Always compare if we have no match yet; otherwise only compare
                // against potentially better matches (longer strings).
                if (length > bestMatchLength &&
                    text.regionMatches(true, start, data[i], 0, length))
                {
                    bestMatch = i;
                    bestMatchLength = length;
                }
            }
            if (bestMatch >= 0)
            {
                calb.set(field, bestMatch);
                return start + bestMatchLength;
            }
            return -start;
        }
    
        /**
         * Performs the same thing as matchString(String, int, int,
         * String[]). This method takes a Map<String, Integer> instead of
         * String[].
         */
        private int matchString(String text, int start, int field,
                                Map<String,Integer> data, CalendarBuilder calb) {
            if (data != null) {
                // TODO: make this default when it's in the spec.
                if (data instanceof SortedMap) {
                    for (String name : data.keySet()) {
                        if (text.regionMatches(true, start, name, 0, name.length())) {
                            calb.set(field, data.get(name));
                            return start + name.length();
                        }
                    }
                    return -start;
                }
    
                String bestMatch = null;
    
                for (String name : data.keySet()) {
                    int length = name.length();
                    if (bestMatch == null || length > bestMatch.length()) {
                        if (text.regionMatches(true, start, name, 0, length)) {
                            bestMatch = name;
                        }
                    }
                }
    
                if (bestMatch != null) {
                    calb.set(field, data.get(bestMatch));
                    return start + bestMatch.length();
                }
            }
            return -start;
        }
    
        private int matchZoneString(String text, int start, String[] zoneNames) {
            for (int i = 1; i <= 4; ++i) {
                // Checking long and short zones [1 & 2],
                // and long and short daylight [3 & 4].
                String zoneName = zoneNames[i];
                if (text.regionMatches(true, start,
                                       zoneName, 0, zoneName.length())) {
                    return i;
                }
            }
            return -1;
        }
    
        private boolean matchDSTString(String text, int start, int zoneIndex, int standardIndex,
                                       String[][] zoneStrings) {
            int index = standardIndex + 2;
            String zoneName  = zoneStrings[zoneIndex][index];
            if (text.regionMatches(true, start,
                                   zoneName, 0, zoneName.length())) {
                return true;
            }
            return false;
        }
    
        /**
         * find time zone 'text' matched zoneStrings and set to internal
         * calendar.
         */
        private int subParseZoneString(String text, int start, CalendarBuilder calb) {
            boolean useSameName = false; // true if standard and daylight time use the same abbreviation.
            TimeZone currentTimeZone = getTimeZone();
    
            // At this point, check for named time zones by looking through
            // the locale data from the TimeZoneNames strings.
            // Want to be able to parse both short and long forms.
            int zoneIndex = formatData.getZoneIndex(currentTimeZone.getID());
            TimeZone tz = null;
            String[][] zoneStrings = formatData.getZoneStringsWrapper();
            String[] zoneNames = null;
            int nameIndex = 0;
            if (zoneIndex != -1) {
                zoneNames = zoneStrings[zoneIndex];
                if ((nameIndex = matchZoneString(text, start, zoneNames)) > 0) {
                    if (nameIndex <= 2) {
                        // Check if the standard name (abbr) and the daylight name are the same.
                        useSameName = zoneNames[nameIndex].equalsIgnoreCase(zoneNames[nameIndex + 2]);
                    }
                    tz = TimeZone.getTimeZone(zoneNames[0]);
                }
            }
            if (tz == null) {
                zoneIndex = formatData.getZoneIndex(TimeZone.getDefault().getID());
                if (zoneIndex != -1) {
                    zoneNames = zoneStrings[zoneIndex];
                    if ((nameIndex = matchZoneString(text, start, zoneNames)) > 0) {
                        if (nameIndex <= 2) {
                            useSameName = zoneNames[nameIndex].equalsIgnoreCase(zoneNames[nameIndex + 2]);
                        }
                        tz = TimeZone.getTimeZone(zoneNames[0]);
                    }
                }
            }
    
            if (tz == null) {
                int len = zoneStrings.length;
                for (int i = 0; i < len; i++) {
                    zoneNames = zoneStrings[i];
                    if ((nameIndex = matchZoneString(text, start, zoneNames)) > 0) {
                        if (nameIndex <= 2) {
                            useSameName = zoneNames[nameIndex].equalsIgnoreCase(zoneNames[nameIndex + 2]);
                        }
                        tz = TimeZone.getTimeZone(zoneNames[0]);
                        break;
                    }
                }
            }
            if (tz != null) { // Matched any ?
                if (!tz.equals(currentTimeZone)) {
                    setTimeZone(tz);
                }
                // If the time zone matched uses the same name
                // (abbreviation) for both standard and daylight time,
                // let the time zone in the Calendar decide which one.
                //
                // Also if tz.getDSTSaving() returns 0 for DST, use tz to
                // determine the local time. (6645292)
                int dstAmount = (nameIndex >= 3) ? tz.getDSTSavings() : 0;
                if (!(useSameName || (nameIndex >= 3 && dstAmount == 0))) {
                    calb.clear(Calendar.ZONE_OFFSET).set(Calendar.DST_OFFSET, dstAmount);
                }
                return (start + zoneNames[nameIndex].length());
            }
            return -start;
        }
    
        /**
         * Parses numeric forms of time zone offset, such as "hh:mm", and
         * sets calb to the parsed value.
         *
         * @param text  the text to be parsed
         * @param start the character position to start parsing
         * @param sign  1: positive; -1: negative
         * @param count 0: 'Z' or "GMT+hh:mm" parsing; 1 - 3: the number of 'X's
         * @param colon true - colon required between hh and mm; false - no colon required
         * @param calb  a CalendarBuilder in which the parsed value is stored
         * @return updated parsed position, or its negative value to indicate a parsing error
         */
        private int subParseNumericZone(String text, int start, int sign, int count,
                                        boolean colon, CalendarBuilder calb) {
            int index = start;
    
          parse:
            try {
                char c = text.charAt(index++);
                // Parse hh
                int hours;
                if (!isDigit(c)) {
                    break parse;
                }
                hours = c - '0';
                c = text.charAt(index++);
                if (isDigit(c)) {
                    hours = hours * 10 + (c - '0');
                } else {
                    // If no colon in RFC 822 or 'X' (ISO), two digits are
                    // required.
                    if (count > 0 || !colon) {
                        break parse;
                    }
                    --index;
                }
                if (hours > 23) {
                    break parse;
                }
                int minutes = 0;
                if (count != 1) {
                    // Proceed with parsing mm
                    c = text.charAt(index++);
                    if (colon) {
                        if (c != ':') {
                            break parse;
                        }
                        c = text.charAt(index++);
                    }
                    if (!isDigit(c)) {
                        break parse;
                    }
                    minutes = c - '0';
                    c = text.charAt(index++);
                    if (!isDigit(c)) {
                        break parse;
                    }
                    minutes = minutes * 10 + (c - '0');
                    if (minutes > 59) {
                        break parse;
                    }
                }
                minutes += hours * 60;
                calb.set(Calendar.ZONE_OFFSET, minutes * MILLIS_PER_MINUTE * sign)
                    .set(Calendar.DST_OFFSET, 0);
                return index;
            } catch (IndexOutOfBoundsException e) {
            }
            return  1 - index; // -(index - 1)
        }
    
        private boolean isDigit(char c) {
            return c >= '0' && c <= '9';
        }
    
        /**
         * Private member function that converts the parsed date strings into
         * timeFields. Returns -start (for ParsePosition) if failed.
         * @param text the time text to be parsed.
         * @param start where to start parsing.
         * @param patternCharIndex the index of the pattern character.
         * @param count the count of a pattern character.
         * @param obeyCount if true, then the next field directly abuts this one,
         * and we should use the count to know when to stop parsing.
         * @param ambiguousYear return parameter; upon return, if ambiguousYear[0]
         * is true, then a two-digit year was parsed and may need to be readjusted.
         * @param origPos origPos.errorIndex is used to return an error index
         * at which a parse error occurred, if matching failure occurs.
         * @return the new start position if matching succeeded; -1 indicating
         * matching failure, otherwise. In case matching failure occurred,
         * an error index is set to origPos.errorIndex.
         */
        private int subParse(String text, int start, int patternCharIndex, int count,
                             boolean obeyCount, boolean[] ambiguousYear,
                             ParsePosition origPos,
                             boolean useFollowingMinusSignAsDelimiter, CalendarBuilder calb) {
            Number number;
            int value = 0;
            ParsePosition pos = new ParsePosition(0);
            pos.index = start;
            if (patternCharIndex == PATTERN_WEEK_YEAR && !calendar.isWeekDateSupported()) {
                // use calendar year 'y' instead
                patternCharIndex = PATTERN_YEAR;
            }
            int field = PATTERN_INDEX_TO_CALENDAR_FIELD[patternCharIndex];
    
            // If there are any spaces here, skip over them.  If we hit the end
            // of the string, then fail.
            for (;;) {
                if (pos.index >= text.length()) {
                    origPos.errorIndex = start;
                    return -1;
                }
                char c = text.charAt(pos.index);
                if (c != ' ' && c != '\t') {
                    break;
                }
                ++pos.index;
            }
            // Remember the actual start index
            int actualStart = pos.index;
    
          parsing:
            {
                // We handle a few special cases here where we need to parse
                // a number value.  We handle further, more generic cases below.  We need
                // to handle some of them here because some fields require extra processing on
                // the parsed value.
                if (patternCharIndex == PATTERN_HOUR_OF_DAY1 ||
                    patternCharIndex == PATTERN_HOUR1 ||
                    (patternCharIndex == PATTERN_MONTH && count <= 2) ||
                    patternCharIndex == PATTERN_YEAR ||
                    patternCharIndex == PATTERN_WEEK_YEAR) {
                    // It would be good to unify this with the obeyCount logic below,
                    // but that's going to be difficult.
                    if (obeyCount) {
                        if ((start+count) > text.length()) {
                            break parsing;
                        }
                        number = numberFormat.parse(text.substring(0, start+count), pos);
                    } else {
                        number = numberFormat.parse(text, pos);
                    }
                    if (number == null) {
                        if (patternCharIndex != PATTERN_YEAR || calendar instanceof GregorianCalendar) {
                            break parsing;
                        }
                    } else {
                        value = number.intValue();
    
                        if (useFollowingMinusSignAsDelimiter && (value < 0) &&
                            (((pos.index < text.length()) &&
                             (text.charAt(pos.index) != minusSign)) ||
                             ((pos.index == text.length()) &&
                              (text.charAt(pos.index-1) == minusSign)))) {
                            value = -value;
                            pos.index--;
                        }
                    }
                }
    
                boolean useDateFormatSymbols = useDateFormatSymbols();
    
                int index;
                switch (patternCharIndex) {
                case PATTERN_ERA: // 'G'
                    if (useDateFormatSymbols) {
                        if ((index = matchString(text, start, Calendar.ERA, formatData.getEras(), calb)) > 0) {
                            return index;
                        }
                    } else {
                        Map<String, Integer> map = getDisplayNamesMap(field, locale);
                        if ((index = matchString(text, start, field, map, calb)) > 0) {
                            return index;
                        }
                    }
                    break parsing;
    
                case PATTERN_WEEK_YEAR: // 'Y'
                case PATTERN_YEAR:      // 'y'
                    if (!(calendar instanceof GregorianCalendar)) {
                        // calendar might have text representations for year values,
                        // such as "\u5143" in JapaneseImperialCalendar.
                        int style = (count >= 4) ? Calendar.LONG : Calendar.SHORT;
                        Map<String, Integer> map = calendar.getDisplayNames(field, style, locale);
                        if (map != null) {
                            if ((index = matchString(text, start, field, map, calb)) > 0) {
                                return index;
                            }
                        }
                        calb.set(field, value);
                        return pos.index;
                    }
    
                    // If there are 3 or more YEAR pattern characters, this indicates
                    // that the year value is to be treated literally, without any
                    // two-digit year adjustments (e.g., from "01" to 2001).  Otherwise
                    // we made adjustments to place the 2-digit year in the proper
                    // century, for parsed strings from "00" to "99".  Any other string
                    // is treated literally:  "2250", "-1", "1", "002".
                    if (count <= 2 && (pos.index - actualStart) == 2
                        && Character.isDigit(text.charAt(actualStart))
                        && Character.isDigit(text.charAt(actualStart + 1))) {
                        // Assume for example that the defaultCenturyStart is 6/18/1903.
                        // This means that two-digit years will be forced into the range
                        // 6/18/1903 to 6/17/2003.  As a result, years 00, 01, and 02
                        // correspond to 2000, 2001, and 2002.  Years 04, 05, etc. correspond
                        // to 1904, 1905, etc.  If the year is 03, then it is 2003 if the
                        // other fields specify a date before 6/18, or 1903 if they specify a
                        // date afterwards.  As a result, 03 is an ambiguous year.  All other
                        // two-digit years are unambiguous.
                        int ambiguousTwoDigitYear = defaultCenturyStartYear % 100;
                        ambiguousYear[0] = value == ambiguousTwoDigitYear;
                        value += (defaultCenturyStartYear/100)*100 +
                            (value < ambiguousTwoDigitYear ? 100 : 0);
                    }
                    calb.set(field, value);
                    return pos.index;
    
                case PATTERN_MONTH: // 'M'
                    if (count <= 2) // i.e., M or MM.
                    {
                        // Don't want to parse the month if it is a string
                        // while pattern uses numeric style: M or MM.
                        // [We computed 'value' above.]
                        calb.set(Calendar.MONTH, value - 1);
                        return pos.index;
                    }
    
                    if (useDateFormatSymbols) {
                        // count >= 3 // i.e., MMM or MMMM
                        // Want to be able to parse both short and long forms.
                        // Try count == 4 first:
                        int newStart;
                        if ((newStart = matchString(text, start, Calendar.MONTH,
                                                    formatData.getMonths(), calb)) > 0) {
                            return newStart;
                        }
                        // count == 4 failed, now try count == 3
                        if ((index = matchString(text, start, Calendar.MONTH,
                                                 formatData.getShortMonths(), calb)) > 0) {
                            return index;
                        }
                    } else {
                        Map<String, Integer> map = getDisplayNamesMap(field, locale);
                        if ((index = matchString(text, start, field, map, calb)) > 0) {
                            return index;
                        }
                    }
                    break parsing;
    
                case PATTERN_HOUR_OF_DAY1: // 'k' 1-based.  eg, 23:59 + 1 hour =>> 24:59
                    if (!isLenient()) {
                        // Validate the hour value in non-lenient
                        if (value < 1 || value > 24) {
                            break parsing;
                        }
                    }
                    // [We computed 'value' above.]
                    if (value == calendar.getMaximum(Calendar.HOUR_OF_DAY) + 1) {
                        value = 0;
                    }
                    calb.set(Calendar.HOUR_OF_DAY, value);
                    return pos.index;
    
                case PATTERN_DAY_OF_WEEK:  // 'E'
                    {
                        if (useDateFormatSymbols) {
                            // Want to be able to parse both short and long forms.
                            // Try count == 4 (DDDD) first:
                            int newStart;
                            if ((newStart=matchString(text, start, Calendar.DAY_OF_WEEK,
                                                      formatData.getWeekdays(), calb)) > 0) {
                                return newStart;
                            }
                            // DDDD failed, now try DDD
                            if ((index = matchString(text, start, Calendar.DAY_OF_WEEK,
                                                     formatData.getShortWeekdays(), calb)) > 0) {
                                return index;
                            }
                        } else {
                            int[] styles = { Calendar.LONG, Calendar.SHORT };
                            for (int style : styles) {
                                Map<String,Integer> map = calendar.getDisplayNames(field, style, locale);
                                if ((index = matchString(text, start, field, map, calb)) > 0) {
                                    return index;
                                }
                            }
                        }
                    }
                    break parsing;
    
                case PATTERN_AM_PM:    // 'a'
                    if (useDateFormatSymbols) {
                        if ((index = matchString(text, start, Calendar.AM_PM,
                                                 formatData.getAmPmStrings(), calb)) > 0) {
                            return index;
                        }
                    } else {
                        Map<String,Integer> map = getDisplayNamesMap(field, locale);
                        if ((index = matchString(text, start, field, map, calb)) > 0) {
                            return index;
                        }
                    }
                    break parsing;
    
                case PATTERN_HOUR1: // 'h' 1-based.  eg, 11PM + 1 hour =>> 12 AM
                    if (!isLenient()) {
                        // Validate the hour value in non-lenient
                        if (value < 1 || value > 12) {
                            break parsing;
                        }
                    }
                    // [We computed 'value' above.]
                    if (value == calendar.getLeastMaximum(Calendar.HOUR) + 1) {
                        value = 0;
                    }
                    calb.set(Calendar.HOUR, value);
                    return pos.index;
    
                case PATTERN_ZONE_NAME:  // 'z'
                case PATTERN_ZONE_VALUE: // 'Z'
                    {
                        int sign = 0;
                        try {
                            char c = text.charAt(pos.index);
                            if (c == '+') {
                                sign = 1;
                            } else if (c == '-') {
                                sign = -1;
                            }
                            if (sign == 0) {
                                // Try parsing a custom time zone "GMT+hh:mm" or "GMT".
                                if ((c == 'G' || c == 'g')
                                    && (text.length() - start) >= GMT.length()
                                    && text.regionMatches(true, start, GMT, 0, GMT.length())) {
                                    pos.index = start + GMT.length();
    
                                    if ((text.length() - pos.index) > 0) {
                                        c = text.charAt(pos.index);
                                        if (c == '+') {
                                            sign = 1;
                                        } else if (c == '-') {
                                            sign = -1;
                                        }
                                    }
    
                                    if (sign == 0) {    /* "GMT" without offset */
                                        calb.set(Calendar.ZONE_OFFSET, 0)
                                            .set(Calendar.DST_OFFSET, 0);
                                        return pos.index;
                                    }
    
                                    // Parse the rest as "hh:mm"
                                    int i = subParseNumericZone(text, ++pos.index,
                                                                sign, 0, true, calb);
                                    if (i > 0) {
                                        return i;
                                    }
                                    pos.index = -i;
                                } else {
                                    // Try parsing the text as a time zone
                                    // name or abbreviation.
                                    int i = subParseZoneString(text, pos.index, calb);
                                    if (i > 0) {
                                        return i;
                                    }
                                    pos.index = -i;
                                }
                            } else {
                                // Parse the rest as "hhmm" (RFC 822)
                                int i = subParseNumericZone(text, ++pos.index,
                                                            sign, 0, false, calb);
                                if (i > 0) {
                                    return i;
                                }
                                pos.index = -i;
                            }
                        } catch (IndexOutOfBoundsException e) {
                        }
                    }
                    break parsing;
    
                case PATTERN_ISO_ZONE:   // 'X'
                    {
                        if ((text.length() - pos.index) <= 0) {
                            break parsing;
                        }
    
                        int sign;
                        char c = text.charAt(pos.index);
                        if (c == 'Z') {
                            calb.set(Calendar.ZONE_OFFSET, 0).set(Calendar.DST_OFFSET, 0);
                            return ++pos.index;
                        }
    
                        // parse text as "+/-hh[[:]mm]" based on count
                        if (c == '+') {
                            sign = 1;
                        } else if (c == '-') {
                            sign = -1;
                        } else {
                            ++pos.index;
                            break parsing;
                        }
                        int i = subParseNumericZone(text, ++pos.index, sign, count,
                                                    count == 3, calb);
                        if (i > 0) {
                            return i;
                        }
                        pos.index = -i;
                    }
                    break parsing;
    
                default:
             // case PATTERN_DAY_OF_MONTH:         // 'd'
             // case PATTERN_HOUR_OF_DAY0:         // 'H' 0-based.  eg, 23:59 + 1 hour =>> 00:59
             // case PATTERN_MINUTE:               // 'm'
             // case PATTERN_SECOND:               // 's'
             // case PATTERN_MILLISECOND:          // 'S'
             // case PATTERN_DAY_OF_YEAR:          // 'D'
             // case PATTERN_DAY_OF_WEEK_IN_MONTH: // 'F'
             // case PATTERN_WEEK_OF_YEAR:         // 'w'
             // case PATTERN_WEEK_OF_MONTH:        // 'W'
             // case PATTERN_HOUR0:                // 'K' 0-based.  eg, 11PM + 1 hour =>> 0 AM
             // case PATTERN_ISO_DAY_OF_WEEK:      // 'u' (pseudo field);
    
                    // Handle "generic" fields
                    if (obeyCount) {
                        if ((start+count) > text.length()) {
                            break parsing;
                        }
                        number = numberFormat.parse(text.substring(0, start+count), pos);
                    } else {
                        number = numberFormat.parse(text, pos);
                    }
                    if (number != null) {
                        value = number.intValue();
    
                        if (useFollowingMinusSignAsDelimiter && (value < 0) &&
                            (((pos.index < text.length()) &&
                             (text.charAt(pos.index) != minusSign)) ||
                             ((pos.index == text.length()) &&
                              (text.charAt(pos.index-1) == minusSign)))) {
                            value = -value;
                            pos.index--;
                        }
    
                        calb.set(field, value);
                        return pos.index;
                    }
                    break parsing;
                }
            }
    
            // Parsing failed.
            origPos.errorIndex = pos.index;
            return -1;
        }
    
        /**
         * Returns true if the DateFormatSymbols has been set explicitly or locale
         * is null.
         */
        private boolean useDateFormatSymbols() {
            return useDateFormatSymbols || locale == null;
        }
    
        /**
         * Translates a pattern, mapping each character in the from string to the
         * corresponding character in the to string.
         *
         * @exception IllegalArgumentException if the given pattern is invalid
         */
        private String translatePattern(String pattern, String from, String to) {
            StringBuilder result = new StringBuilder();
            boolean inQuote = false;
            for (int i = 0; i < pattern.length(); ++i) {
                char c = pattern.charAt(i);
                if (inQuote) {
                    if (c == '\'') {
                        inQuote = false;
                    }
                }
                else {
                    if (c == '\'') {
                        inQuote = true;
                    } else if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {
                        int ci = from.indexOf(c);
                        if (ci >= 0) {
                            // patternChars is longer than localPatternChars due
                            // to serialization compatibility. The pattern letters
                            // unsupported by localPatternChars pass through.
                            if (ci < to.length()) {
                                c = to.charAt(ci);
                            }
                        } else {
                            throw new IllegalArgumentException("Illegal pattern " +
                                                               " character '" +
                                                               c + "'");
                        }
                    }
                }
                result.append(c);
            }
            if (inQuote) {
                throw new IllegalArgumentException("Unfinished quote in pattern");
            }
            return result.toString();
        }
    
        /**
         * Returns a pattern string describing this date format.
         *
         * @return a pattern string describing this date format.
         */
        public String toPattern() {
            return pattern;
        }
    
        /**
         * Returns a localized pattern string describing this date format.
         *
         * @return a localized pattern string describing this date format.
         */
        public String toLocalizedPattern() {
            return translatePattern(pattern,
                                    DateFormatSymbols.patternChars,
                                    formatData.getLocalPatternChars());
        }
    
        /**
         * Applies the given pattern string to this date format.
         *
         * @param pattern the new date and time pattern for this date format
         * @exception NullPointerException if the given pattern is null
         * @exception IllegalArgumentException if the given pattern is invalid
         */
        public void applyPattern(String pattern)
        {
            applyPatternImpl(pattern);
        }
    
        private void applyPatternImpl(String pattern) {
            compiledPattern = compile(pattern);
            this.pattern = pattern;
        }
    
        /**
         * Applies the given localized pattern string to this date format.
         *
         * @param pattern a String to be mapped to the new date and time format
         *        pattern for this format
         * @exception NullPointerException if the given pattern is null
         * @exception IllegalArgumentException if the given pattern is invalid
         */
        public void applyLocalizedPattern(String pattern) {
             String p = translatePattern(pattern,
                                         formatData.getLocalPatternChars(),
                                         DateFormatSymbols.patternChars);
             compiledPattern = compile(p);
             this.pattern = p;
        }
    
        /**
         * Gets a copy of the date and time format symbols of this date format.
         *
         * @return the date and time format symbols of this date format
         * @see #setDateFormatSymbols
         */
        public DateFormatSymbols getDateFormatSymbols()
        {
            return (DateFormatSymbols)formatData.clone();
        }
    
        /**
         * Sets the date and time format symbols of this date format.
         *
         * @param newFormatSymbols the new date and time format symbols
         * @exception NullPointerException if the given newFormatSymbols is null
         * @see #getDateFormatSymbols
         */
        public void setDateFormatSymbols(DateFormatSymbols newFormatSymbols)
        {
            this.formatData = (DateFormatSymbols)newFormatSymbols.clone();
            useDateFormatSymbols = true;
        }
    
        /**
         * Creates a copy of this <code>SimpleDateFormat</code>. This also
         * clones the format's date format symbols.
         *
         * @return a clone of this <code>SimpleDateFormat</code>
         */
        @Override
        public Object clone() {
            SimpleDateFormat other = (SimpleDateFormat) super.clone();
            other.formatData = (DateFormatSymbols) formatData.clone();
            return other;
        }
    
        /**
         * Returns the hash code value for this <code>SimpleDateFormat</code> object.
         *
         * @return the hash code value for this <code>SimpleDateFormat</code> object.
         */
        @Override
        public int hashCode()
        {
            return pattern.hashCode();
            // just enough fields for a reasonable distribution
        }
    
        /**
         * Compares the given object with this <code>SimpleDateFormat</code> for
         * equality.
         *
         * @return true if the given object is equal to this
         * <code>SimpleDateFormat</code>
         */
        @Override
        public boolean equals(Object obj)
        {
            if (!super.equals(obj)) {
                return false; // super does class check
            }
            SimpleDateFormat that = (SimpleDateFormat) obj;
            return (pattern.equals(that.pattern)
                    && formatData.equals(that.formatData));
        }
    
        private static final int[] REST_OF_STYLES = {
            Calendar.SHORT_STANDALONE, Calendar.LONG_FORMAT, Calendar.LONG_STANDALONE,
        };
        private Map<String, Integer> getDisplayNamesMap(int field, Locale locale) {
            Map<String, Integer> map = calendar.getDisplayNames(field, Calendar.SHORT_FORMAT, locale);
            // Get all SHORT and LONG styles (avoid NARROW styles).
            for (int style : REST_OF_STYLES) {
                Map<String, Integer> m = calendar.getDisplayNames(field, style, locale);
                if (m != null) {
                    map.putAll(m);
                }
            }
            return map;
        }
    
        /**
         * After reading an object from the input stream, the format
         * pattern in the object is verified.
         * <p>
         * @exception InvalidObjectException if the pattern is invalid
         */
        private void readObject(ObjectInputStream stream)
                             throws IOException, ClassNotFoundException {
            stream.defaultReadObject();
    
            try {
                compiledPattern = compile(pattern);
            } catch (Exception e) {
                throw new InvalidObjectException("invalid pattern");
            }
    
            if (serialVersionOnStream < 1) {
                // didn't have defaultCenturyStart field
                initializeDefaultCentury();
            }
            else {
                // fill in dependent transient field
                parseAmbiguousDatesAsAfter(defaultCenturyStart);
            }
            serialVersionOnStream = currentSerialVersion;
    
            // If the deserialized object has a SimpleTimeZone, try
            // to replace it with a ZoneInfo equivalent in order to
            // be compatible with the SimpleTimeZone-based
            // implementation as much as possible.
            TimeZone tz = getTimeZone();
            if (tz instanceof SimpleTimeZone) {
                String id = tz.getID();
                TimeZone zi = TimeZone.getTimeZone(id);
                if (zi != null && zi.hasSameRules(tz) && zi.getID().equals(id)) {
                    setTimeZone(zi);
                }
            }
        }
    
        /**
         * Analyze the negative subpattern of DecimalFormat and set/update values
         * as necessary.
         */
        private void checkNegativeNumberExpression() {
            if ((numberFormat instanceof DecimalFormat) &&
                !numberFormat.equals(originalNumberFormat)) {
                String numberPattern = ((DecimalFormat)numberFormat).toPattern();
                if (!numberPattern.equals(originalNumberPattern)) {
                    hasFollowingMinusSign = false;
    
                    int separatorIndex = numberPattern.indexOf(';');
                    // If the negative subpattern is not absent, we have to analayze
                    // it in order to check if it has a following minus sign.
                    if (separatorIndex > -1) {
                        int minusIndex = numberPattern.indexOf('-', separatorIndex);
                        if ((minusIndex > numberPattern.lastIndexOf('0')) &&
                            (minusIndex > numberPattern.lastIndexOf('#'))) {
                            hasFollowingMinusSign = true;
                            minusSign = ((DecimalFormat)numberFormat).getDecimalFormatSymbols().getMinusSign();
                        }
                    }
                    originalNumberPattern = numberPattern;
                }
                originalNumberFormat = numberFormat;
            }
        }
    
    }
    

      

    #########################

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  • 原文地址:https://www.cnblogs.com/herd/p/16268310.html
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