java/11 : java.base/java/time/format/DateTimeFormatter.java

DateTimeFormatter
https://openjdk.java.net/
GPLv2 + Classpath Exception
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 * Copyright (c) 2008-2012, Stephen Colebourne & Michael Nascimento Santos
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package java.time.format;

import static java.time.temporal.ChronoField.DAY_OF_MONTH;
import static java.time.temporal.ChronoField.DAY_OF_WEEK;
import static java.time.temporal.ChronoField.DAY_OF_YEAR;
import static java.time.temporal.ChronoField.HOUR_OF_DAY;
import static java.time.temporal.ChronoField.MINUTE_OF_HOUR;
import static java.time.temporal.ChronoField.MONTH_OF_YEAR;
import static java.time.temporal.ChronoField.NANO_OF_SECOND;
import static java.time.temporal.ChronoField.SECOND_OF_MINUTE;
import static java.time.temporal.ChronoField.YEAR;

import java.io.IOException;
import java.text.FieldPosition;
import java.text.Format;
import java.text.ParseException;
import java.text.ParsePosition;
import java.time.DateTimeException;
import java.time.Period;
import java.time.ZoneId;
import java.time.ZoneOffset;
import java.time.chrono.ChronoLocalDateTime;
import java.time.chrono.Chronology;
import java.time.chrono.IsoChronology;
import java.time.format.DateTimeFormatterBuilder.CompositePrinterParser;
import java.time.temporal.ChronoField;
import java.time.temporal.IsoFields;
import java.time.temporal.TemporalAccessor;
import java.time.temporal.TemporalField;
import java.time.temporal.TemporalQuery;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Locale;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import sun.util.locale.provider.TimeZoneNameUtility;

Formatter for printing and parsing date-time objects.
 This class provides the main application entry point for printing and parsing and provides common implementations of DateTimeFormatter: 

Using predefined constants, such as ISO_LOCAL_DATE
Using pattern letters, such as uuuu-MMM-dd
Using localized styles, such as long or medium

 More complex formatters are provided by DateTimeFormatterBuilder. 
 The main date-time classes provide two methods - one for formatting, format(DateTimeFormatter formatter), and one for parsing, parse(CharSequence text, DateTimeFormatter formatter). 
For example:
 LocalDate date = LocalDate.now();
 String text = date.format(formatter);
 LocalDate parsedDate = LocalDate.parse(text, formatter);


In addition to the format, formatters can be created with desired Locale,
Chronology, ZoneId, and DecimalStyle.
 The withLocale method returns a new formatter that overrides the locale. The locale affects some aspects of formatting and parsing. For example, the ofLocalizedDate provides a formatter that uses the locale specific date format. 
 The withChronology method returns a new formatter that overrides the chronology. If overridden, the date-time value is converted to the chronology before formatting. During parsing the date-time value is converted to the chronology before it is returned. 
 The withZone method returns a new formatter that overrides the zone. If overridden, the date-time value is converted to a ZonedDateTime with the requested ZoneId before formatting. During parsing the ZoneId is applied before the value is returned. 
 The withDecimalStyle method returns a new formatter that overrides the DecimalStyle. The DecimalStyle symbols are used for formatting and parsing. 
 Some applications may need to use the older java.text.Format class for formatting. The toFormat() method returns an implementation of java.text.Format. 
Predefined Formatters

Predefined Formatters


Formatter
Description
Example




ofLocalizedDate(dateStyle) 
 Formatter with date style from the locale 
 '2011-12-03'


 ofLocalizedTime(timeStyle) 
 Formatter with time style from the locale 
 '10:15:30'


 ofLocalizedDateTime(dateTimeStyle) 
 Formatter with a style for date and time from the locale
 '3 Jun 2008 11:05:30'


 ofLocalizedDateTime(dateStyle,timeStyle) 
 Formatter with date and time styles from the locale 
 '3 Jun 2008 11:05'


 BASIC_ISO_DATE
Basic ISO date  '20111203'


 ISO_LOCAL_DATE
 ISO Local Date 
'2011-12-03'


 ISO_OFFSET_DATE
 ISO Date with offset 
'2011-12-03+01:00'


 ISO_DATE
 ISO Date with or without offset 
 '2011-12-03+01:00'; '2011-12-03'


 ISO_LOCAL_TIME
 Time without offset 
'10:15:30'


 ISO_OFFSET_TIME
 Time with offset 
'10:15:30+01:00'


 ISO_TIME
 Time with or without offset 
'10:15:30+01:00'; '10:15:30'


 ISO_LOCAL_DATE_TIME
 ISO Local Date and Time 
'2011-12-03T10:15:30'


 ISO_OFFSET_DATE_TIME
 Date Time with Offset
'2011-12-03T10:15:30+01:00'


 ISO_ZONED_DATE_TIME
 Zoned Date Time 
'2011-12-03T10:15:30+01:00[Europe/Paris]'


 ISO_DATE_TIME
 Date and time with ZoneId 
'2011-12-03T10:15:30+01:00[Europe/Paris]'


 ISO_ORDINAL_DATE
 Year and day of year 
'2012-337'


 ISO_WEEK_DATE
 Year and Week 
'2012-W48-6'

 ISO_INSTANT
 Date and Time of an Instant 
'2011-12-03T10:15:30Z' 


 RFC_1123_DATE_TIME
 RFC 1123 / RFC 822 
'Tue, 3 Jun 2008 11:05:30 GMT'



Patterns for Formatting and Parsing
 Patterns are based on a simple sequence of letters and symbols. A pattern is used to create a Formatter using the ofPattern(String) and ofPattern(String, Locale) methods. For example, "d MMM uuuu" will format 2011-12-03 as '3 Dec 2011'. A formatter created from a pattern can be used as many times as necessary, it is immutable and is thread-safe. 
For example:
 LocalDate date = LocalDate.now();
 DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy MM dd");
 String text = date.format(formatter);
 LocalDate parsedDate = LocalDate.parse(text, formatter);


All letters 'A' to 'Z' and 'a' to 'z' are reserved as pattern letters. The
following pattern letters are defined:

Pattern Letters and Symbols

 Symbol    Meaning          Presentation  Examples


  G        era                          text               AD; Anno Domini; A
  
u        year                         year               2004; 04
  
y        year-of-era                  year               2004; 04
  
D        day-of-year                  number             189
  
M/L      month-of-year                number/text        7; 07; Jul; July; J
  
d        day-of-month                 number             10
  
g        modified-julian-day          number             2451334
  
Q/q      quarter-of-year              number/text        3; 03; Q3; 3rd quarter
  
Y        week-based-year              year               1996; 96
  
w        week-of-week-based-year      number             27
  
W        week-of-month                number             4
  
E        day-of-week                  text               Tue; Tuesday; T
  
e/c      localized day-of-week        number/text        2; 02; Tue; Tuesday; T
  
F        day-of-week-in-month         number             3
  
a        am-pm-of-day                 text               PM
  
h        clock-hour-of-am-pm (1-12)   number             12
  
K        hour-of-am-pm (0-11)         number             0
  
k        clock-hour-of-day (1-24)     number             24
  
H        hour-of-day (0-23)           number             0
  
m        minute-of-hour               number             30
  
s        second-of-minute             number             55
  
S        fraction-of-second           fraction           978
  
A        milli-of-day                 number             1234
  
n        nano-of-second               number             987654321
  
N        nano-of-day                  number             1234000000
  
V        time-zone ID                 zone-id            America/Los_Angeles; Z; -08:30
  
v        generic time-zone name       zone-name          Pacific Time; PT
  
z        time-zone name               zone-name          Pacific Standard Time; PST
  
O        localized zone-offset        offset-O           GMT+8; GMT+08:00; UTC-08:00
  
X        zone-offset 'Z' for zero     offset-X           Z; -08; -0830; -08:30; -083015; -08:30:15
  
x        zone-offset                  offset-x           +0000; -08; -0830; -08:30; -083015; -08:30:15
  
Z        zone-offset                  offset-Z           +0000; -0800; -08:00
  
p        pad next                     pad modifier       1
  
'        escape for text              delimiter          
  
''       single quote                 literal            '
  
[        optional section start                         
  
]        optional section end                           
  
#        reserved for future use                        
  
{        reserved for future use                        
  
}        reserved for future use                        



The count of pattern letters determines the format.

Text: The text style is determined based on the number of pattern letters used. Less than 4 pattern letters will use the short form. Exactly 4 pattern letters will use the full form. Exactly 5 pattern letters will use the narrow form. Pattern letters 'L', 'c', and 'q' specify the stand-alone form of the text styles. 

Number: If the count of letters is one, then the value is output using
the minimum number of digits and without padding. Otherwise, the count of digits
is used as the width of the output field, with the value zero-padded as necessary.
The following pattern letters have constraints on the count of letters.
Only one letter of 'c' and 'F' can be specified.
Up to two letters of 'd', 'H', 'h', 'K', 'k', 'm', and 's' can be specified.
Up to three letters of 'D' can be specified.

Number/Text: If the count of pattern letters is 3 or greater, use the
Text rules above. Otherwise use the Number rules above.

Fraction: Outputs the nano-of-second field as a fraction-of-second.
The nano-of-second value has nine digits, thus the count of pattern letters
is from 1 to 9. If it is less than 9, then the nano-of-second value is
truncated, with only the most significant digits being output.

Year: The count of letters determines the minimum field width below which padding is used. If the count of letters is two, then a reduced two digit form is used. For printing, this outputs the rightmost two digits. For parsing, this will parse using the base value of 2000, resulting in a year within the range 2000 to 2099 inclusive. If the count of letters is less than four (but not two), then the sign is only output for negative years as per SignStyle.NORMAL. Otherwise, the sign is output if the pad width is exceeded, as per SignStyle.EXCEEDS_PAD. 

ZoneId: This outputs the time-zone ID, such as 'Europe/Paris'. If the count of letters is two, then the time-zone ID is output. Any other count of letters throws IllegalArgumentException. 

Zone names: This outputs the display name of the time-zone ID. If the pattern letter is 'z' the output is the daylight savings aware zone name. If there is insufficient information to determine whether DST applies, the name ignoring daylight savings time will be used. If the count of letters is one, two or three, then the short name is output. If the count of letters is four, then the full name is output. Five or more letters throws IllegalArgumentException. 
 If the pattern letter is 'v' the output provides the zone name ignoring daylight savings time. If the count of letters is one, then the short name is output. If the count of letters is four, then the full name is output. Two, three and five or more letters throw IllegalArgumentException. 

Offset X and x: This formats the offset based on the number of pattern letters. One letter outputs just the hour, such as '+01', unless the minute is non-zero in which case the minute is also output, such as '+0130'. Two letters outputs the hour and minute, without a colon, such as '+0130'. Three letters outputs the hour and minute, with a colon, such as '+01:30'. Four letters outputs the hour and minute and optional second, without a colon, such as '+013015'. Five letters outputs the hour and minute and optional second, with a colon, such as '+01:30:15'. Six or more letters throws IllegalArgumentException. Pattern letter 'X' (upper case) will output 'Z' when the offset to be output would be zero, whereas pattern letter 'x' (lower case) will output '+00', '+0000', or '+00:00'. 

Offset O: This formats the localized offset based on the number of pattern letters. One letter outputs the short form of the localized offset, which is localized offset text, such as 'GMT', with hour without leading zero, optional 2-digit minute and second if non-zero, and colon, for example 'GMT+8'. Four letters outputs the full form, which is localized offset text, such as 'GMT, with 2-digit hour and minute field, optional second field if non-zero, and colon, for example 'GMT+08:00'. Any other count of letters throws IllegalArgumentException. 

Offset Z: This formats the offset based on the number of pattern letters. One, two or three letters outputs the hour and minute, without a colon, such as '+0130'. The output will be '+0000' when the offset is zero. Four letters outputs the full form of localized offset, equivalent to four letters of Offset-O. The output will be the corresponding localized offset text if the offset is zero. Five letters outputs the hour, minute, with optional second if non-zero, with colon. It outputs 'Z' if the offset is zero. Six or more letters throws IllegalArgumentException. 

Optional section: The optional section markers work exactly like calling DateTimeFormatterBuilder.optionalStart() and DateTimeFormatterBuilder.optionalEnd(). 

Pad modifier: Modifies the pattern that immediately follows to be padded with spaces. The pad width is determined by the number of pattern letters. This is the same as calling DateTimeFormatterBuilder.padNext(int). 

For example, 'ppH' outputs the hour-of-day padded on the left with spaces to
a width of 2.

Any unrecognized letter is an error. Any non-letter character, other than
'[', ']', '{', '}', '#' and the single quote will be output directly.
Despite this, it is recommended to use single quotes around all characters
that you want to output directly to ensure that future changes do not break
your application.
Resolving
 Parsing is implemented as a two-phase operation. First, the text is parsed using the layout defined by the formatter, producing a Map of field to value, a ZoneId and a Chronology. Second, the parsed data is resolved, by validating, combining and
simplifying the various fields into more useful ones.
 Five parsing methods are supplied by this class. Four of these perform both the parse and resolve phases. The fifth method, parseUnresolved(CharSequence, ParsePosition), only performs the first phase, leaving the result unresolved. As such, it is essentially a low-level operation. 

The resolve phase is controlled by two parameters, set on this class.
 The ResolverStyle is an enum that offers three different approaches, strict, smart and lenient. The smart option is the default. It can be set using withResolverStyle(ResolverStyle). 
 The withResolverFields(TemporalField...) parameter allows the set of fields that will be resolved to be filtered before resolving starts. For example, if the formatter has parsed a year, month, day-of-month and day-of-year, then there are two approaches to resolve a date: (year + month + day-of-month) and (year + day-of-year). The resolver fields allows one of the two approaches to be selected. If no resolver fields are set then both approaches must result in the same date. 

Resolving separate fields to form a complete date and time is a complex
process with behaviour distributed across a number of classes.
It follows these steps:

The chronology is determined. The chronology of the result is either the chronology that was parsed, or if no chronology was parsed, it is the chronology set on this class, or if that is null, it is IsoChronology. 
The ChronoField date fields are resolved. This is achieved using Chronology.resolveDate(Map<TemporalField,Long>, ResolverStyle). Documentation about field resolution is located in the implementation of Chronology. 
The ChronoField time fields are resolved. This is documented on ChronoField and is the same for all chronologies. 
Any fields that are not ChronoField are processed. This is achieved using TemporalField.resolve(Map<TemporalField,Long>, TemporalAccessor, ResolverStyle). Documentation about field resolution is located in the implementation of TemporalField. 
The ChronoField date and time fields are re-resolved. This allows fields in step four to produce ChronoField values and have them be processed into dates and times. 
A LocalTime is formed if there is at least an hour-of-day available. This involves providing default values for minute, second and fraction of second. 
Any remaining unresolved fields are cross-checked against any
date and/or time that was resolved. Thus, an earlier stage would resolve
(year + month + day-of-month) to a date, and this stage would check that
day-of-week was valid for the date.
If an excess number of days was parsed then it is added to the date if a date is available. 
 If a second-based field is present, but LocalTime was not parsed, then the resolver ensures that milli, micro and nano second values are available to meet the contract of ChronoField. These will be set to zero if missing. 
If both date and time were parsed and either an offset or zone is present, the field ChronoField.INSTANT_SECONDS is created. If an offset was parsed then the offset will be combined with the LocalDateTime to form the instant, with any zone ignored. If a ZoneId was parsed without an offset then the zone will be combined with the LocalDateTime to form the instant using the rules of ChronoLocalDateTime.atZone(ZoneId). 
Implementation Requirements: 
This class is immutable and thread-safe.
Since: 1.8/**
 * Formatter for printing and parsing date-time objects.
 * <p>
 * This class provides the main application entry point for printing and parsing
 * and provides common implementations of {@code DateTimeFormatter}:
 * <ul>
 * <li>Using predefined constants, such as {@link #ISO_LOCAL_DATE}</li>
 * <li>Using pattern letters, such as {@code uuuu-MMM-dd}</li>
 * <li>Using localized styles, such as {@code long} or {@code medium}</li>
 * </ul>
 * <p>
 * More complex formatters are provided by
 * {@link DateTimeFormatterBuilder DateTimeFormatterBuilder}.
 *
 * <p>
 * The main date-time classes provide two methods - one for formatting,
 * {@code format(DateTimeFormatter formatter)}, and one for parsing,
 * {@code parse(CharSequence text, DateTimeFormatter formatter)}.
 * <p>For example:
 * <blockquote><pre>
 *  LocalDate date = LocalDate.now();
 *  String text = date.format(formatter);
 *  LocalDate parsedDate = LocalDate.parse(text, formatter);
 * </pre></blockquote>
 * <p>
 * In addition to the format, formatters can be created with desired Locale,
 * Chronology, ZoneId, and DecimalStyle.
 * <p>
 * The {@link #withLocale withLocale} method returns a new formatter that
 * overrides the locale. The locale affects some aspects of formatting and
 * parsing. For example, the {@link #ofLocalizedDate ofLocalizedDate} provides a
 * formatter that uses the locale specific date format.
 * <p>
 * The {@link #withChronology withChronology} method returns a new formatter
 * that overrides the chronology. If overridden, the date-time value is
 * converted to the chronology before formatting. During parsing the date-time
 * value is converted to the chronology before it is returned.
 * <p>
 * The {@link #withZone withZone} method returns a new formatter that overrides
 * the zone. If overridden, the date-time value is converted to a ZonedDateTime
 * with the requested ZoneId before formatting. During parsing the ZoneId is
 * applied before the value is returned.
 * <p>
 * The {@link #withDecimalStyle withDecimalStyle} method returns a new formatter that
 * overrides the {@link DecimalStyle}. The DecimalStyle symbols are used for
 * formatting and parsing.
 * <p>
 * Some applications may need to use the older {@link Format java.text.Format}
 * class for formatting. The {@link #toFormat()} method returns an
 * implementation of {@code java.text.Format}.
 *
 * <h3 id="predefined">Predefined Formatters</h3>
 * <table class="striped" style="text-align:left">
 * <caption>Predefined Formatters</caption>
 * <thead>
 * <tr>
 * <th scope="col">Formatter</th>
 * <th scope="col">Description</th>
 * <th scope="col">Example</th>
 * </tr>
 * </thead>
 * <tbody>
 * <tr>
 * <th scope="row">{@link #ofLocalizedDate ofLocalizedDate(dateStyle)} </th>
 * <td> Formatter with date style from the locale </td>
 * <td> '2011-12-03'</td>
 * </tr>
 * <tr>
 * <th scope="row"> {@link #ofLocalizedTime ofLocalizedTime(timeStyle)} </th>
 * <td> Formatter with time style from the locale </td>
 * <td> '10:15:30'</td>
 * </tr>
 * <tr>
 * <th scope="row"> {@link #ofLocalizedDateTime ofLocalizedDateTime(dateTimeStyle)} </th>
 * <td> Formatter with a style for date and time from the locale</td>
 * <td> '3 Jun 2008 11:05:30'</td>
 * </tr>
 * <tr>
 * <th scope="row"> {@link #ofLocalizedDateTime ofLocalizedDateTime(dateStyle,timeStyle)}
 * </th>
 * <td> Formatter with date and time styles from the locale </td>
 * <td> '3 Jun 2008 11:05'</td>
 * </tr>
 * <tr>
 * <th scope="row"> {@link #BASIC_ISO_DATE}</th>
 * <td>Basic ISO date </td> <td>'20111203'</td>
 * </tr>
 * <tr>
 * <th scope="row"> {@link #ISO_LOCAL_DATE}</th>
 * <td> ISO Local Date </td>
 * <td>'2011-12-03'</td>
 * </tr>
 * <tr>
 * <th scope="row"> {@link #ISO_OFFSET_DATE}</th>
 * <td> ISO Date with offset </td>
 * <td>'2011-12-03+01:00'</td>
 * </tr>
 * <tr>
 * <th scope="row"> {@link #ISO_DATE}</th>
 * <td> ISO Date with or without offset </td>
 * <td> '2011-12-03+01:00'; '2011-12-03'</td>
 * </tr>
 * <tr>
 * <th scope="row"> {@link #ISO_LOCAL_TIME}</th>
 * <td> Time without offset </td>
 * <td>'10:15:30'</td>
 * </tr>
 * <tr>
 * <th scope="row"> {@link #ISO_OFFSET_TIME}</th>
 * <td> Time with offset </td>
 * <td>'10:15:30+01:00'</td>
 * </tr>
 * <tr>
 * <th scope="row"> {@link #ISO_TIME}</th>
 * <td> Time with or without offset </td>
 * <td>'10:15:30+01:00'; '10:15:30'</td>
 * </tr>
 * <tr>
 * <th scope="row"> {@link #ISO_LOCAL_DATE_TIME}</th>
 * <td> ISO Local Date and Time </td>
 * <td>'2011-12-03T10:15:30'</td>
 * </tr>
 * <tr>
 * <th scope="row"> {@link #ISO_OFFSET_DATE_TIME}</th>
 * <td> Date Time with Offset
 * </td><td>'2011-12-03T10:15:30+01:00'</td>
 * </tr>
 * <tr>
 * <th scope="row"> {@link #ISO_ZONED_DATE_TIME}</th>
 * <td> Zoned Date Time </td>
 * <td>'2011-12-03T10:15:30+01:00[Europe/Paris]'</td>
 * </tr>
 * <tr>
 * <th scope="row"> {@link #ISO_DATE_TIME}</th>
 * <td> Date and time with ZoneId </td>
 * <td>'2011-12-03T10:15:30+01:00[Europe/Paris]'</td>
 * </tr>
 * <tr>
 * <th scope="row"> {@link #ISO_ORDINAL_DATE}</th>
 * <td> Year and day of year </td>
 * <td>'2012-337'</td>
 * </tr>
 * <tr>
 * <th scope="row"> {@link #ISO_WEEK_DATE}</th>
 * <td> Year and Week </td>
 * <td>'2012-W48-6'</td></tr>
 * <tr>
 * <th scope="row"> {@link #ISO_INSTANT}</th>
 * <td> Date and Time of an Instant </td>
 * <td>'2011-12-03T10:15:30Z' </td>
 * </tr>
 * <tr>
 * <th scope="row"> {@link #RFC_1123_DATE_TIME}</th>
 * <td> RFC 1123 / RFC 822 </td>
 * <td>'Tue, 3 Jun 2008 11:05:30 GMT'</td>
 * </tr>
 * </tbody>
 * </table>
 *
 * <h3 id="patterns">Patterns for Formatting and Parsing</h3>
 * Patterns are based on a simple sequence of letters and symbols.
 * A pattern is used to create a Formatter using the
 * {@link #ofPattern(String)} and {@link #ofPattern(String, Locale)} methods.
 * For example,
 * {@code "d MMM uuuu"} will format 2011-12-03 as '3&nbsp;Dec&nbsp;2011'.
 * A formatter created from a pattern can be used as many times as necessary,
 * it is immutable and is thread-safe.
 * <p>
 * For example:
 * <blockquote><pre>
 *  LocalDate date = LocalDate.now();
 *  DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy MM dd");
 *  String text = date.format(formatter);
 *  LocalDate parsedDate = LocalDate.parse(text, formatter);
 * </pre></blockquote>
 * <p>
 * All letters 'A' to 'Z' and 'a' to 'z' are reserved as pattern letters. The
 * following pattern letters are defined:
 * <table class="striped">
 * <caption>Pattern Letters and Symbols</caption>
 * <thead>
 *  <tr><th scope="col">Symbol</th>   <th scope="col">Meaning</th>         <th scope="col">Presentation</th> <th scope="col">Examples</th>
 * </thead>
 * <tbody>
 *   <tr><th scope="row">G</th>       <td>era</td>                         <td>text</td>              <td>AD; Anno Domini; A</td>
 *   <tr><th scope="row">u</th>       <td>year</td>                        <td>year</td>              <td>2004; 04</td>
 *   <tr><th scope="row">y</th>       <td>year-of-era</td>                 <td>year</td>              <td>2004; 04</td>
 *   <tr><th scope="row">D</th>       <td>day-of-year</td>                 <td>number</td>            <td>189</td>
 *   <tr><th scope="row">M/L</th>     <td>month-of-year</td>               <td>number/text</td>       <td>7; 07; Jul; July; J</td>
 *   <tr><th scope="row">d</th>       <td>day-of-month</td>                <td>number</td>            <td>10</td>
 *   <tr><th scope="row">g</th>       <td>modified-julian-day</td>         <td>number</td>            <td>2451334</td>
 *
 *   <tr><th scope="row">Q/q</th>     <td>quarter-of-year</td>             <td>number/text</td>       <td>3; 03; Q3; 3rd quarter</td>
 *   <tr><th scope="row">Y</th>       <td>week-based-year</td>             <td>year</td>              <td>1996; 96</td>
 *   <tr><th scope="row">w</th>       <td>week-of-week-based-year</td>     <td>number</td>            <td>27</td>
 *   <tr><th scope="row">W</th>       <td>week-of-month</td>               <td>number</td>            <td>4</td>
 *   <tr><th scope="row">E</th>       <td>day-of-week</td>                 <td>text</td>              <td>Tue; Tuesday; T</td>
 *   <tr><th scope="row">e/c</th>     <td>localized day-of-week</td>       <td>number/text</td>       <td>2; 02; Tue; Tuesday; T</td>
 *   <tr><th scope="row">F</th>       <td>day-of-week-in-month</td>        <td>number</td>            <td>3</td>
 *
 *   <tr><th scope="row">a</th>       <td>am-pm-of-day</td>                <td>text</td>              <td>PM</td>
 *   <tr><th scope="row">h</th>       <td>clock-hour-of-am-pm (1-12)</td>  <td>number</td>            <td>12</td>
 *   <tr><th scope="row">K</th>       <td>hour-of-am-pm (0-11)</td>        <td>number</td>            <td>0</td>
 *   <tr><th scope="row">k</th>       <td>clock-hour-of-day (1-24)</td>    <td>number</td>            <td>24</td>
 *
 *   <tr><th scope="row">H</th>       <td>hour-of-day (0-23)</td>          <td>number</td>            <td>0</td>
 *   <tr><th scope="row">m</th>       <td>minute-of-hour</td>              <td>number</td>            <td>30</td>
 *   <tr><th scope="row">s</th>       <td>second-of-minute</td>            <td>number</td>            <td>55</td>
 *   <tr><th scope="row">S</th>       <td>fraction-of-second</td>          <td>fraction</td>          <td>978</td>
 *   <tr><th scope="row">A</th>       <td>milli-of-day</td>                <td>number</td>            <td>1234</td>
 *   <tr><th scope="row">n</th>       <td>nano-of-second</td>              <td>number</td>            <td>987654321</td>
 *   <tr><th scope="row">N</th>       <td>nano-of-day</td>                 <td>number</td>            <td>1234000000</td>
 *
 *   <tr><th scope="row">V</th>       <td>time-zone ID</td>                <td>zone-id</td>           <td>America/Los_Angeles; Z; -08:30</td>
 *   <tr><th scope="row">v</th>       <td>generic time-zone name</td>      <td>zone-name</td>         <td>Pacific Time; PT</td>
 *   <tr><th scope="row">z</th>       <td>time-zone name</td>              <td>zone-name</td>         <td>Pacific Standard Time; PST</td>
 *   <tr><th scope="row">O</th>       <td>localized zone-offset</td>       <td>offset-O</td>          <td>GMT+8; GMT+08:00; UTC-08:00</td>
 *   <tr><th scope="row">X</th>       <td>zone-offset 'Z' for zero</td>    <td>offset-X</td>          <td>Z; -08; -0830; -08:30; -083015; -08:30:15</td>
 *   <tr><th scope="row">x</th>       <td>zone-offset</td>                 <td>offset-x</td>          <td>+0000; -08; -0830; -08:30; -083015; -08:30:15</td>
 *   <tr><th scope="row">Z</th>       <td>zone-offset</td>                 <td>offset-Z</td>          <td>+0000; -0800; -08:00</td>
 *
 *   <tr><th scope="row">p</th>       <td>pad next</td>                    <td>pad modifier</td>      <td>1</td>
 *
 *   <tr><th scope="row">'</th>       <td>escape for text</td>             <td>delimiter</td>         <td></td>
 *   <tr><th scope="row">''</th>      <td>single quote</td>                <td>literal</td>           <td>'</td>
 *   <tr><th scope="row">[</th>       <td>optional section start</td>      <td></td>                  <td></td>
 *   <tr><th scope="row">]</th>       <td>optional section end</td>        <td></td>                  <td></td>
 *   <tr><th scope="row">#</th>       <td>reserved for future use</td>     <td></td>                  <td></td>
 *   <tr><th scope="row">{</th>       <td>reserved for future use</td>     <td></td>                  <td></td>
 *   <tr><th scope="row">}</th>       <td>reserved for future use</td>     <td></td>                  <td></td>
 * </tbody>
 * </table>
 * <p>
 * The count of pattern letters determines the format.
 * <p>
 * <b>Text</b>: The text style is determined based on the number of pattern
 * letters used. Less than 4 pattern letters will use the
 * {@link TextStyle#SHORT short form}. Exactly 4 pattern letters will use the
 * {@link TextStyle#FULL full form}. Exactly 5 pattern letters will use the
 * {@link TextStyle#NARROW narrow form}.
 * Pattern letters 'L', 'c', and 'q' specify the stand-alone form of the text styles.
 * <p>
 * <b>Number</b>: If the count of letters is one, then the value is output using
 * the minimum number of digits and without padding. Otherwise, the count of digits
 * is used as the width of the output field, with the value zero-padded as necessary.
 * The following pattern letters have constraints on the count of letters.
 * Only one letter of 'c' and 'F' can be specified.
 * Up to two letters of 'd', 'H', 'h', 'K', 'k', 'm', and 's' can be specified.
 * Up to three letters of 'D' can be specified.
 * <p>
 * <b>Number/Text</b>: If the count of pattern letters is 3 or greater, use the
 * Text rules above. Otherwise use the Number rules above.
 * <p>
 * <b>Fraction</b>: Outputs the nano-of-second field as a fraction-of-second.
 * The nano-of-second value has nine digits, thus the count of pattern letters
 * is from 1 to 9. If it is less than 9, then the nano-of-second value is
 * truncated, with only the most significant digits being output.
 * <p>
 * <b>Year</b>: The count of letters determines the minimum field width below
 * which padding is used. If the count of letters is two, then a
 * {@link DateTimeFormatterBuilder#appendValueReduced reduced} two digit form is
 * used. For printing, this outputs the rightmost two digits. For parsing, this
 * will parse using the base value of 2000, resulting in a year within the range
 * 2000 to 2099 inclusive. If the count of letters is less than four (but not
 * two), then the sign is only output for negative years as per
 * {@link SignStyle#NORMAL}. Otherwise, the sign is output if the pad width is
 * exceeded, as per {@link SignStyle#EXCEEDS_PAD}.
 * <p>
 * <b>ZoneId</b>: This outputs the time-zone ID, such as 'Europe/Paris'. If the
 * count of letters is two, then the time-zone ID is output. Any other count of
 * letters throws {@code IllegalArgumentException}.
 * <p>
 * <b>Zone names</b>: This outputs the display name of the time-zone ID. If the
 * pattern letter is 'z' the output is the daylight savings aware zone name.
 * If there is insufficient information to determine whether DST applies,
 * the name ignoring daylight savings time will be used.
 * If the count of letters is one, two or three, then the short name is output.
 * If the count of letters is four, then the full name is output.
 * Five or more letters throws {@code IllegalArgumentException}.
 * <p>
 * If the pattern letter is 'v' the output provides the zone name ignoring
 * daylight savings time. If the count of letters is one, then the short name is output.
 * If the count of letters is four, then the full name is output.
 * Two, three and five or more letters throw {@code IllegalArgumentException}.
 * <p>
 * <b>Offset X and x</b>: This formats the offset based on the number of pattern
 * letters. One letter outputs just the hour, such as '+01', unless the minute
 * is non-zero in which case the minute is also output, such as '+0130'. Two
 * letters outputs the hour and minute, without a colon, such as '+0130'. Three
 * letters outputs the hour and minute, with a colon, such as '+01:30'. Four
 * letters outputs the hour and minute and optional second, without a colon,
 * such as '+013015'. Five letters outputs the hour and minute and optional
 * second, with a colon, such as '+01:30:15'. Six or more letters throws
 * {@code IllegalArgumentException}. Pattern letter 'X' (upper case) will output
 * 'Z' when the offset to be output would be zero, whereas pattern letter 'x'
 * (lower case) will output '+00', '+0000', or '+00:00'.
 * <p>
 * <b>Offset O</b>: This formats the localized offset based on the number of
 * pattern letters. One letter outputs the {@linkplain TextStyle#SHORT short}
 * form of the localized offset, which is localized offset text, such as 'GMT',
 * with hour without leading zero, optional 2-digit minute and second if
 * non-zero, and colon, for example 'GMT+8'. Four letters outputs the
 * {@linkplain TextStyle#FULL full} form, which is localized offset text,
 * such as 'GMT, with 2-digit hour and minute field, optional second field
 * if non-zero, and colon, for example 'GMT+08:00'. Any other count of letters
 * throws {@code IllegalArgumentException}.
 * <p>
 * <b>Offset Z</b>: This formats the offset based on the number of pattern
 * letters. One, two or three letters outputs the hour and minute, without a
 * colon, such as '+0130'. The output will be '+0000' when the offset is zero.
 * Four letters outputs the {@linkplain TextStyle#FULL full} form of localized
 * offset, equivalent to four letters of Offset-O. The output will be the
 * corresponding localized offset text if the offset is zero. Five
 * letters outputs the hour, minute, with optional second if non-zero, with
 * colon. It outputs 'Z' if the offset is zero.
 * Six or more letters throws {@code IllegalArgumentException}.
 * <p>
 * <b>Optional section</b>: The optional section markers work exactly like
 * calling {@link DateTimeFormatterBuilder#optionalStart()} and
 * {@link DateTimeFormatterBuilder#optionalEnd()}.
 * <p>
 * <b>Pad modifier</b>: Modifies the pattern that immediately follows to be
 * padded with spaces. The pad width is determined by the number of pattern
 * letters. This is the same as calling
 * {@link DateTimeFormatterBuilder#padNext(int)}.
 * <p>
 * For example, 'ppH' outputs the hour-of-day padded on the left with spaces to
 * a width of 2.
 * <p>
 * Any unrecognized letter is an error. Any non-letter character, other than
 * '[', ']', '{', '}', '#' and the single quote will be output directly.
 * Despite this, it is recommended to use single quotes around all characters
 * that you want to output directly to ensure that future changes do not break
 * your application.
 *
 * <h3 id="resolving">Resolving</h3>
 * Parsing is implemented as a two-phase operation.
 * First, the text is parsed using the layout defined by the formatter, producing
 * a {@code Map} of field to value, a {@code ZoneId} and a {@code Chronology}.
 * Second, the parsed data is <em>resolved</em>, by validating, combining and
 * simplifying the various fields into more useful ones.
 * <p>
 * Five parsing methods are supplied by this class.
 * Four of these perform both the parse and resolve phases.
 * The fifth method, {@link #parseUnresolved(CharSequence, ParsePosition)},
 * only performs the first phase, leaving the result unresolved.
 * As such, it is essentially a low-level operation.
 * <p>
 * The resolve phase is controlled by two parameters, set on this class.
 * <p>
 * The {@link ResolverStyle} is an enum that offers three different approaches,
 * strict, smart and lenient. The smart option is the default.
 * It can be set using {@link #withResolverStyle(ResolverStyle)}.
 * <p>
 * The {@link #withResolverFields(TemporalField...)} parameter allows the
 * set of fields that will be resolved to be filtered before resolving starts.
 * For example, if the formatter has parsed a year, month, day-of-month
 * and day-of-year, then there are two approaches to resolve a date:
 * (year + month + day-of-month) and (year + day-of-year).
 * The resolver fields allows one of the two approaches to be selected.
 * If no resolver fields are set then both approaches must result in the same date.
 * <p>
 * Resolving separate fields to form a complete date and time is a complex
 * process with behaviour distributed across a number of classes.
 * It follows these steps:
 * <ol>
 * <li>The chronology is determined.
 * The chronology of the result is either the chronology that was parsed,
 * or if no chronology was parsed, it is the chronology set on this class,
 * or if that is null, it is {@code IsoChronology}.
 * <li>The {@code ChronoField} date fields are resolved.
 * This is achieved using {@link Chronology#resolveDate(Map, ResolverStyle)}.
 * Documentation about field resolution is located in the implementation
 * of {@code Chronology}.
 * <li>The {@code ChronoField} time fields are resolved.
 * This is documented on {@link ChronoField} and is the same for all chronologies.
 * <li>Any fields that are not {@code ChronoField} are processed.
 * This is achieved using {@link TemporalField#resolve(Map, TemporalAccessor, ResolverStyle)}.
 * Documentation about field resolution is located in the implementation
 * of {@code TemporalField}.
 * <li>The {@code ChronoField} date and time fields are re-resolved.
 * This allows fields in step four to produce {@code ChronoField} values
 * and have them be processed into dates and times.
 * <li>A {@code LocalTime} is formed if there is at least an hour-of-day available.
 * This involves providing default values for minute, second and fraction of second.
 * <li>Any remaining unresolved fields are cross-checked against any
 * date and/or time that was resolved. Thus, an earlier stage would resolve
 * (year + month + day-of-month) to a date, and this stage would check that
 * day-of-week was valid for the date.
 * <li>If an {@linkplain #parsedExcessDays() excess number of days}
 * was parsed then it is added to the date if a date is available.
 * <li> If a second-based field is present, but {@code LocalTime} was not parsed,
 * then the resolver ensures that milli, micro and nano second values are
 * available to meet the contract of {@link ChronoField}.
 * These will be set to zero if missing.
 * <li>If both date and time were parsed and either an offset or zone is present,
 * the field {@link ChronoField#INSTANT_SECONDS} is created.
 * If an offset was parsed then the offset will be combined with the
 * {@code LocalDateTime} to form the instant, with any zone ignored.
 * If a {@code ZoneId} was parsed without an offset then the zone will be
 * combined with the {@code LocalDateTime} to form the instant using the rules
 * of {@link ChronoLocalDateTime#atZone(ZoneId)}.
 * </ol>
 *
 * @implSpec
 * This class is immutable and thread-safe.
 *
 * @since 1.8
 */
public final class DateTimeFormatter {

    The printer and/or parser to use, not null.
/**
     * The printer and/or parser to use, not null.
     */
    private final CompositePrinterParser printerParser;
    The locale to use for formatting, not null.
/**
     * The locale to use for formatting, not null.
     */
    private final Locale locale;
    The symbols to use for formatting, not null.
/**
     * The symbols to use for formatting, not null.
     */
    private final DecimalStyle decimalStyle;
    The resolver style to use, not null.
/**
     * The resolver style to use, not null.
     */
    private final ResolverStyle resolverStyle;
    The fields to use in resolving, null for all fields.
/**
     * The fields to use in resolving, null for all fields.
     */
    private final Set<TemporalField> resolverFields;
    The chronology to use for formatting, null for no override.
/**
     * The chronology to use for formatting, null for no override.
     */
    private final Chronology chrono;
    The zone to use for formatting, null for no override.
/**
     * The zone to use for formatting, null for no override.
     */
    private final ZoneId zone;

    //-----------------------------------------------------------------------
    Creates a formatter using the specified pattern.

This method will create a formatter based on a simple
pattern of letters and symbols as described in the class documentation. For example, d MMM uuuu will format 2011-12-03 as '3 Dec 2011'. 
 The formatter will use the default FORMAT locale. This can be changed using withLocale(Locale) on the returned formatter. Alternatively use the ofPattern(String, Locale) variant of this method. 
 The returned formatter has no override chronology or zone. It uses SMART resolver style. 
Params: pattern –  the pattern to use, not null
Throws: IllegalArgumentException – if the pattern is invalid
See Also: DateTimeFormatterBuilder.appendPattern(String)
Returns: the formatter based on the pattern, not null/**
     * Creates a formatter using the specified pattern.
     * <p>
     * This method will create a formatter based on a simple
     * <a href="#patterns">pattern of letters and symbols</a>
     * as described in the class documentation.
     * For example, {@code d MMM uuuu} will format 2011-12-03 as '3 Dec 2011'.
     * <p>
     * The formatter will use the {@link Locale#getDefault(Locale.Category) default FORMAT locale}.
     * This can be changed using {@link DateTimeFormatter#withLocale(Locale)} on the returned formatter.
     * Alternatively use the {@link #ofPattern(String, Locale)} variant of this method.
     * <p>
     * The returned formatter has no override chronology or zone.
     * It uses {@link ResolverStyle#SMART SMART} resolver style.
     *
     * @param pattern  the pattern to use, not null
     * @return the formatter based on the pattern, not null
     * @throws IllegalArgumentException if the pattern is invalid
     * @see DateTimeFormatterBuilder#appendPattern(String)
     */
    public static DateTimeFormatter ofPattern(String pattern) {
        return new DateTimeFormatterBuilder().appendPattern(pattern).toFormatter();
    }

    Creates a formatter using the specified pattern and locale.

This method will create a formatter based on a simple
pattern of letters and symbols as described in the class documentation. For example, d MMM uuuu will format 2011-12-03 as '3 Dec 2011'. 
 The formatter will use the specified locale. This can be changed using withLocale(Locale) on the returned formatter. 
 The returned formatter has no override chronology or zone. It uses SMART resolver style. 
Params: pattern –  the pattern to use, not null
locale –  the locale to use, not null
Throws: IllegalArgumentException – if the pattern is invalid
See Also: DateTimeFormatterBuilder.appendPattern(String)
Returns: the formatter based on the pattern, not null/**
     * Creates a formatter using the specified pattern and locale.
     * <p>
     * This method will create a formatter based on a simple
     * <a href="#patterns">pattern of letters and symbols</a>
     * as described in the class documentation.
     * For example, {@code d MMM uuuu} will format 2011-12-03 as '3 Dec 2011'.
     * <p>
     * The formatter will use the specified locale.
     * This can be changed using {@link DateTimeFormatter#withLocale(Locale)} on the returned formatter.
     * <p>
     * The returned formatter has no override chronology or zone.
     * It uses {@link ResolverStyle#SMART SMART} resolver style.
     *
     * @param pattern  the pattern to use, not null
     * @param locale  the locale to use, not null
     * @return the formatter based on the pattern, not null
     * @throws IllegalArgumentException if the pattern is invalid
     * @see DateTimeFormatterBuilder#appendPattern(String)
     */
    public static DateTimeFormatter ofPattern(String pattern, Locale locale) {
        return new DateTimeFormatterBuilder().appendPattern(pattern).toFormatter(locale);
    }

    //-----------------------------------------------------------------------
    Returns a locale specific date format for the ISO chronology.

This returns a formatter that will format or parse a date.
The exact format pattern used varies by locale.
 The locale is determined from the formatter. The formatter returned directly by this method will use the default FORMAT locale. The locale can be controlled using withLocale(Locale) on the result of this method. 
 Note that the localized pattern is looked up lazily. This DateTimeFormatter holds the style required and the locale, looking up the pattern required on demand. 
 The returned formatter has a chronology of ISO set to ensure dates in other calendar systems are correctly converted. It has no override zone and uses the SMART resolver style. 
Params: dateStyle –  the formatter style to obtain, not null
Returns: the date formatter, not null/**
     * Returns a locale specific date format for the ISO chronology.
     * <p>
     * This returns a formatter that will format or parse a date.
     * The exact format pattern used varies by locale.
     * <p>
     * The locale is determined from the formatter. The formatter returned directly by
     * this method will use the {@link Locale#getDefault(Locale.Category) default FORMAT locale}.
     * The locale can be controlled using {@link DateTimeFormatter#withLocale(Locale) withLocale(Locale)}
     * on the result of this method.
     * <p>
     * Note that the localized pattern is looked up lazily.
     * This {@code DateTimeFormatter} holds the style required and the locale,
     * looking up the pattern required on demand.
     * <p>
     * The returned formatter has a chronology of ISO set to ensure dates in
     * other calendar systems are correctly converted.
     * It has no override zone and uses the {@link ResolverStyle#SMART SMART} resolver style.
     *
     * @param dateStyle  the formatter style to obtain, not null
     * @return the date formatter, not null
     */
    public static DateTimeFormatter ofLocalizedDate(FormatStyle dateStyle) {
        Objects.requireNonNull(dateStyle, "dateStyle");
        return new DateTimeFormatterBuilder().appendLocalized(dateStyle, null)
                .toFormatter(ResolverStyle.SMART, IsoChronology.INSTANCE);
    }

    Returns a locale specific time format for the ISO chronology.

This returns a formatter that will format or parse a time.
The exact format pattern used varies by locale.
 The locale is determined from the formatter. The formatter returned directly by this method will use the default FORMAT locale. The locale can be controlled using withLocale(Locale) on the result of this method. 
 Note that the localized pattern is looked up lazily. This DateTimeFormatter holds the style required and the locale, looking up the pattern required on demand. 
 The returned formatter has a chronology of ISO set to ensure dates in other calendar systems are correctly converted. It has no override zone and uses the SMART resolver style. The FULL and LONG styles typically require a time-zone. When formatting using these styles, a ZoneId must be available, either by using ZonedDateTime or withZone. 
Params: timeStyle –  the formatter style to obtain, not null
Returns: the time formatter, not null/**
     * Returns a locale specific time format for the ISO chronology.
     * <p>
     * This returns a formatter that will format or parse a time.
     * The exact format pattern used varies by locale.
     * <p>
     * The locale is determined from the formatter. The formatter returned directly by
     * this method will use the {@link Locale#getDefault(Locale.Category) default FORMAT locale}.
     * The locale can be controlled using {@link DateTimeFormatter#withLocale(Locale) withLocale(Locale)}
     * on the result of this method.
     * <p>
     * Note that the localized pattern is looked up lazily.
     * This {@code DateTimeFormatter} holds the style required and the locale,
     * looking up the pattern required on demand.
     * <p>
     * The returned formatter has a chronology of ISO set to ensure dates in
     * other calendar systems are correctly converted.
     * It has no override zone and uses the {@link ResolverStyle#SMART SMART} resolver style.
     * The {@code FULL} and {@code LONG} styles typically require a time-zone.
     * When formatting using these styles, a {@code ZoneId} must be available,
     * either by using {@code ZonedDateTime} or {@link DateTimeFormatter#withZone}.
     *
     * @param timeStyle  the formatter style to obtain, not null
     * @return the time formatter, not null
     */
    public static DateTimeFormatter ofLocalizedTime(FormatStyle timeStyle) {
        Objects.requireNonNull(timeStyle, "timeStyle");
        return new DateTimeFormatterBuilder().appendLocalized(null, timeStyle)
                .toFormatter(ResolverStyle.SMART, IsoChronology.INSTANCE);
    }

    Returns a locale specific date-time formatter for the ISO chronology.

This returns a formatter that will format or parse a date-time.
The exact format pattern used varies by locale.
 The locale is determined from the formatter. The formatter returned directly by this method will use the default FORMAT locale. The locale can be controlled using withLocale(Locale) on the result of this method. 
 Note that the localized pattern is looked up lazily. This DateTimeFormatter holds the style required and the locale, looking up the pattern required on demand. 
 The returned formatter has a chronology of ISO set to ensure dates in other calendar systems are correctly converted. It has no override zone and uses the SMART resolver style. The FULL and LONG styles typically require a time-zone. When formatting using these styles, a ZoneId must be available, either by using ZonedDateTime or withZone. 
Params: dateTimeStyle –  the formatter style to obtain, not null
Returns: the date-time formatter, not null/**
     * Returns a locale specific date-time formatter for the ISO chronology.
     * <p>
     * This returns a formatter that will format or parse a date-time.
     * The exact format pattern used varies by locale.
     * <p>
     * The locale is determined from the formatter. The formatter returned directly by
     * this method will use the {@link Locale#getDefault(Locale.Category) default FORMAT locale}.
     * The locale can be controlled using {@link DateTimeFormatter#withLocale(Locale) withLocale(Locale)}
     * on the result of this method.
     * <p>
     * Note that the localized pattern is looked up lazily.
     * This {@code DateTimeFormatter} holds the style required and the locale,
     * looking up the pattern required on demand.
     * <p>
     * The returned formatter has a chronology of ISO set to ensure dates in
     * other calendar systems are correctly converted.
     * It has no override zone and uses the {@link ResolverStyle#SMART SMART} resolver style.
     * The {@code FULL} and {@code LONG} styles typically require a time-zone.
     * When formatting using these styles, a {@code ZoneId} must be available,
     * either by using {@code ZonedDateTime} or {@link DateTimeFormatter#withZone}.
     *
     * @param dateTimeStyle  the formatter style to obtain, not null
     * @return the date-time formatter, not null
     */
    public static DateTimeFormatter ofLocalizedDateTime(FormatStyle dateTimeStyle) {
        Objects.requireNonNull(dateTimeStyle, "dateTimeStyle");
        return new DateTimeFormatterBuilder().appendLocalized(dateTimeStyle, dateTimeStyle)
                .toFormatter(ResolverStyle.SMART, IsoChronology.INSTANCE);
    }

    Returns a locale specific date and time format for the ISO chronology.

This returns a formatter that will format or parse a date-time.
The exact format pattern used varies by locale.
 The locale is determined from the formatter. The formatter returned directly by this method will use the default FORMAT locale. The locale can be controlled using withLocale(Locale) on the result of this method. 
 Note that the localized pattern is looked up lazily. This DateTimeFormatter holds the style required and the locale, looking up the pattern required on demand. 
 The returned formatter has a chronology of ISO set to ensure dates in other calendar systems are correctly converted. It has no override zone and uses the SMART resolver style. The FULL and LONG styles typically require a time-zone. When formatting using these styles, a ZoneId must be available, either by using ZonedDateTime or withZone. 
Params: dateStyle –  the date formatter style to obtain, not null
timeStyle –  the time formatter style to obtain, not null
Returns: the date, time or date-time formatter, not null/**
     * Returns a locale specific date and time format for the ISO chronology.
     * <p>
     * This returns a formatter that will format or parse a date-time.
     * The exact format pattern used varies by locale.
     * <p>
     * The locale is determined from the formatter. The formatter returned directly by
     * this method will use the {@link Locale#getDefault() default FORMAT locale}.
     * The locale can be controlled using {@link DateTimeFormatter#withLocale(Locale) withLocale(Locale)}
     * on the result of this method.
     * <p>
     * Note that the localized pattern is looked up lazily.
     * This {@code DateTimeFormatter} holds the style required and the locale,
     * looking up the pattern required on demand.
     * <p>
     * The returned formatter has a chronology of ISO set to ensure dates in
     * other calendar systems are correctly converted.
     * It has no override zone and uses the {@link ResolverStyle#SMART SMART} resolver style.
     * The {@code FULL} and {@code LONG} styles typically require a time-zone.
     * When formatting using these styles, a {@code ZoneId} must be available,
     * either by using {@code ZonedDateTime} or {@link DateTimeFormatter#withZone}.
     *
     * @param dateStyle  the date formatter style to obtain, not null
     * @param timeStyle  the time formatter style to obtain, not null
     * @return the date, time or date-time formatter, not null
     */
    public static DateTimeFormatter ofLocalizedDateTime(FormatStyle dateStyle, FormatStyle timeStyle) {
        Objects.requireNonNull(dateStyle, "dateStyle");
        Objects.requireNonNull(timeStyle, "timeStyle");
        return new DateTimeFormatterBuilder().appendLocalized(dateStyle, timeStyle)
                .toFormatter(ResolverStyle.SMART, IsoChronology.INSTANCE);
    }

    //-----------------------------------------------------------------------
    The ISO date formatter that formats or parses a date without an
offset, such as '2011-12-03'.

This returns an immutable formatter capable of formatting and parsing
the ISO-8601 extended local date format.
The format consists of:

Four digits or more for the year. Years in the range 0000 to 9999 will be pre-padded by zero to ensure four digits. Years outside that range will have a prefixed positive or negative symbol. 
A dash
Two digits for the month-of-year. This is pre-padded by zero to ensure two digits. 
A dash
Two digits for the day-of-month. This is pre-padded by zero to ensure two digits. 
 The returned formatter has a chronology of ISO set to ensure dates in other calendar systems are correctly converted. It has no override zone and uses the STRICT resolver style. /**
     * The ISO date formatter that formats or parses a date without an
     * offset, such as '2011-12-03'.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * the ISO-8601 extended local date format.
     * The format consists of:
     * <ul>
     * <li>Four digits or more for the {@link ChronoField#YEAR year}.
     * Years in the range 0000 to 9999 will be pre-padded by zero to ensure four digits.
     * Years outside that range will have a prefixed positive or negative symbol.
     * <li>A dash
     * <li>Two digits for the {@link ChronoField#MONTH_OF_YEAR month-of-year}.
     *  This is pre-padded by zero to ensure two digits.
     * <li>A dash
     * <li>Two digits for the {@link ChronoField#DAY_OF_MONTH day-of-month}.
     *  This is pre-padded by zero to ensure two digits.
     * </ul>
     * <p>
     * The returned formatter has a chronology of ISO set to ensure dates in
     * other calendar systems are correctly converted.
     * It has no override zone and uses the {@link ResolverStyle#STRICT STRICT} resolver style.
     */
    public static final DateTimeFormatter ISO_LOCAL_DATE;
    static {
        ISO_LOCAL_DATE = new DateTimeFormatterBuilder()
                .appendValue(YEAR, 4, 10, SignStyle.EXCEEDS_PAD)
                .appendLiteral('-')
                .appendValue(MONTH_OF_YEAR, 2)
                .appendLiteral('-')
                .appendValue(DAY_OF_MONTH, 2)
                .toFormatter(ResolverStyle.STRICT, IsoChronology.INSTANCE);
    }

    //-----------------------------------------------------------------------
    The ISO date formatter that formats or parses a date with an
offset, such as '2011-12-03+01:00'.

This returns an immutable formatter capable of formatting and parsing
the ISO-8601 extended offset date format.
The format consists of:

The ISO_LOCAL_DATE 
The offset ID. If the offset has seconds then they will be handled even though this is not part of the ISO-8601 standard. Parsing is case insensitive. 
 The returned formatter has a chronology of ISO set to ensure dates in other calendar systems are correctly converted. It has no override zone and uses the STRICT resolver style. /**
     * The ISO date formatter that formats or parses a date with an
     * offset, such as '2011-12-03+01:00'.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * the ISO-8601 extended offset date format.
     * The format consists of:
     * <ul>
     * <li>The {@link #ISO_LOCAL_DATE}
     * <li>The {@link ZoneOffset#getId() offset ID}. If the offset has seconds then
     *  they will be handled even though this is not part of the ISO-8601 standard.
     *  Parsing is case insensitive.
     * </ul>
     * <p>
     * The returned formatter has a chronology of ISO set to ensure dates in
     * other calendar systems are correctly converted.
     * It has no override zone and uses the {@link ResolverStyle#STRICT STRICT} resolver style.
     */
    public static final DateTimeFormatter ISO_OFFSET_DATE;
    static {
        ISO_OFFSET_DATE = new DateTimeFormatterBuilder()
                .parseCaseInsensitive()
                .append(ISO_LOCAL_DATE)
                .appendOffsetId()
                .toFormatter(ResolverStyle.STRICT, IsoChronology.INSTANCE);
    }

    //-----------------------------------------------------------------------
    The ISO date formatter that formats or parses a date with the
offset if available, such as '2011-12-03' or '2011-12-03+01:00'.

This returns an immutable formatter capable of formatting and parsing
the ISO-8601 extended date format.
The format consists of:

The ISO_LOCAL_DATE 
If the offset is not available then the format is complete.
The offset ID. If the offset has seconds then they will be handled even though this is not part of the ISO-8601 standard. Parsing is case insensitive. 
 As this formatter has an optional element, it may be necessary to parse using parseBest. 
 The returned formatter has a chronology of ISO set to ensure dates in other calendar systems are correctly converted. It has no override zone and uses the STRICT resolver style. /**
     * The ISO date formatter that formats or parses a date with the
     * offset if available, such as '2011-12-03' or '2011-12-03+01:00'.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * the ISO-8601 extended date format.
     * The format consists of:
     * <ul>
     * <li>The {@link #ISO_LOCAL_DATE}
     * <li>If the offset is not available then the format is complete.
     * <li>The {@link ZoneOffset#getId() offset ID}. If the offset has seconds then
     *  they will be handled even though this is not part of the ISO-8601 standard.
     *  Parsing is case insensitive.
     * </ul>
     * <p>
     * As this formatter has an optional element, it may be necessary to parse using
     * {@link DateTimeFormatter#parseBest}.
     * <p>
     * The returned formatter has a chronology of ISO set to ensure dates in
     * other calendar systems are correctly converted.
     * It has no override zone and uses the {@link ResolverStyle#STRICT STRICT} resolver style.
     */
    public static final DateTimeFormatter ISO_DATE;
    static {
        ISO_DATE = new DateTimeFormatterBuilder()
                .parseCaseInsensitive()
                .append(ISO_LOCAL_DATE)
                .optionalStart()
                .appendOffsetId()
                .toFormatter(ResolverStyle.STRICT, IsoChronology.INSTANCE);
    }

    //-----------------------------------------------------------------------
    The ISO time formatter that formats or parses a time without an
offset, such as '10:15' or '10:15:30'.

This returns an immutable formatter capable of formatting and parsing
the ISO-8601 extended local time format.
The format consists of:

Two digits for the hour-of-day. This is pre-padded by zero to ensure two digits. 
A colon
Two digits for the minute-of-hour. This is pre-padded by zero to ensure two digits. 
If the second-of-minute is not available then the format is complete.
A colon
Two digits for the second-of-minute. This is pre-padded by zero to ensure two digits. 
If the nano-of-second is zero or not available then the format is complete.
A decimal point
One to nine digits for the nano-of-second. As many digits will be output as required. 
 The returned formatter has no override chronology or zone. It uses the STRICT resolver style. /**
     * The ISO time formatter that formats or parses a time without an
     * offset, such as '10:15' or '10:15:30'.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * the ISO-8601 extended local time format.
     * The format consists of:
     * <ul>
     * <li>Two digits for the {@link ChronoField#HOUR_OF_DAY hour-of-day}.
     *  This is pre-padded by zero to ensure two digits.
     * <li>A colon
     * <li>Two digits for the {@link ChronoField#MINUTE_OF_HOUR minute-of-hour}.
     *  This is pre-padded by zero to ensure two digits.
     * <li>If the second-of-minute is not available then the format is complete.
     * <li>A colon
     * <li>Two digits for the {@link ChronoField#SECOND_OF_MINUTE second-of-minute}.
     *  This is pre-padded by zero to ensure two digits.
     * <li>If the nano-of-second is zero or not available then the format is complete.
     * <li>A decimal point
     * <li>One to nine digits for the {@link ChronoField#NANO_OF_SECOND nano-of-second}.
     *  As many digits will be output as required.
     * </ul>
     * <p>
     * The returned formatter has no override chronology or zone.
     * It uses the {@link ResolverStyle#STRICT STRICT} resolver style.
     */
    public static final DateTimeFormatter ISO_LOCAL_TIME;
    static {
        ISO_LOCAL_TIME = new DateTimeFormatterBuilder()
                .appendValue(HOUR_OF_DAY, 2)
                .appendLiteral(':')
                .appendValue(MINUTE_OF_HOUR, 2)
                .optionalStart()
                .appendLiteral(':')
                .appendValue(SECOND_OF_MINUTE, 2)
                .optionalStart()
                .appendFraction(NANO_OF_SECOND, 0, 9, true)
                .toFormatter(ResolverStyle.STRICT, null);
    }

    //-----------------------------------------------------------------------
    The ISO time formatter that formats or parses a time with an
offset, such as '10:15+01:00' or '10:15:30+01:00'.

This returns an immutable formatter capable of formatting and parsing
the ISO-8601 extended offset time format.
The format consists of:

The ISO_LOCAL_TIME 
The offset ID. If the offset has seconds then they will be handled even though this is not part of the ISO-8601 standard. Parsing is case insensitive. 
 The returned formatter has no override chronology or zone. It uses the STRICT resolver style. /**
     * The ISO time formatter that formats or parses a time with an
     * offset, such as '10:15+01:00' or '10:15:30+01:00'.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * the ISO-8601 extended offset time format.
     * The format consists of:
     * <ul>
     * <li>The {@link #ISO_LOCAL_TIME}
     * <li>The {@link ZoneOffset#getId() offset ID}. If the offset has seconds then
     *  they will be handled even though this is not part of the ISO-8601 standard.
     *  Parsing is case insensitive.
     * </ul>
     * <p>
     * The returned formatter has no override chronology or zone.
     * It uses the {@link ResolverStyle#STRICT STRICT} resolver style.
     */
    public static final DateTimeFormatter ISO_OFFSET_TIME;
    static {
        ISO_OFFSET_TIME = new DateTimeFormatterBuilder()
                .parseCaseInsensitive()
                .append(ISO_LOCAL_TIME)
                .appendOffsetId()
                .toFormatter(ResolverStyle.STRICT, null);
    }

    //-----------------------------------------------------------------------
    The ISO time formatter that formats or parses a time, with the
offset if available, such as '10:15', '10:15:30' or '10:15:30+01:00'.

This returns an immutable formatter capable of formatting and parsing
the ISO-8601 extended offset time format.
The format consists of:

The ISO_LOCAL_TIME 
If the offset is not available then the format is complete.
The offset ID. If the offset has seconds then they will be handled even though this is not part of the ISO-8601 standard. Parsing is case insensitive. 
 As this formatter has an optional element, it may be necessary to parse using parseBest. 
 The returned formatter has no override chronology or zone. It uses the STRICT resolver style. /**
     * The ISO time formatter that formats or parses a time, with the
     * offset if available, such as '10:15', '10:15:30' or '10:15:30+01:00'.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * the ISO-8601 extended offset time format.
     * The format consists of:
     * <ul>
     * <li>The {@link #ISO_LOCAL_TIME}
     * <li>If the offset is not available then the format is complete.
     * <li>The {@link ZoneOffset#getId() offset ID}. If the offset has seconds then
     *  they will be handled even though this is not part of the ISO-8601 standard.
     *  Parsing is case insensitive.
     * </ul>
     * <p>
     * As this formatter has an optional element, it may be necessary to parse using
     * {@link DateTimeFormatter#parseBest}.
     * <p>
     * The returned formatter has no override chronology or zone.
     * It uses the {@link ResolverStyle#STRICT STRICT} resolver style.
     */
    public static final DateTimeFormatter ISO_TIME;
    static {
        ISO_TIME = new DateTimeFormatterBuilder()
                .parseCaseInsensitive()
                .append(ISO_LOCAL_TIME)
                .optionalStart()
                .appendOffsetId()
                .toFormatter(ResolverStyle.STRICT, null);
    }

    //-----------------------------------------------------------------------
    The ISO date-time formatter that formats or parses a date-time without
an offset, such as '2011-12-03T10:15:30'.

This returns an immutable formatter capable of formatting and parsing
the ISO-8601 extended offset date-time format.
The format consists of:

The ISO_LOCAL_DATE 
The letter 'T'. Parsing is case insensitive.
The ISO_LOCAL_TIME 
 The returned formatter has a chronology of ISO set to ensure dates in other calendar systems are correctly converted. It has no override zone and uses the STRICT resolver style. /**
     * The ISO date-time formatter that formats or parses a date-time without
     * an offset, such as '2011-12-03T10:15:30'.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * the ISO-8601 extended offset date-time format.
     * The format consists of:
     * <ul>
     * <li>The {@link #ISO_LOCAL_DATE}
     * <li>The letter 'T'. Parsing is case insensitive.
     * <li>The {@link #ISO_LOCAL_TIME}
     * </ul>
     * <p>
     * The returned formatter has a chronology of ISO set to ensure dates in
     * other calendar systems are correctly converted.
     * It has no override zone and uses the {@link ResolverStyle#STRICT STRICT} resolver style.
     */
    public static final DateTimeFormatter ISO_LOCAL_DATE_TIME;
    static {
        ISO_LOCAL_DATE_TIME = new DateTimeFormatterBuilder()
                .parseCaseInsensitive()
                .append(ISO_LOCAL_DATE)
                .appendLiteral('T')
                .append(ISO_LOCAL_TIME)
                .toFormatter(ResolverStyle.STRICT, IsoChronology.INSTANCE);
    }

    //-----------------------------------------------------------------------
    The ISO date-time formatter that formats or parses a date-time with an
offset, such as '2011-12-03T10:15:30+01:00'.

This returns an immutable formatter capable of formatting and parsing
the ISO-8601 extended offset date-time format.
The format consists of:

The ISO_LOCAL_DATE_TIME 
The offset ID. If the offset has seconds then they will be handled even though this is not part of the ISO-8601 standard. The offset parsing is lenient, which allows the minutes and seconds to be optional. Parsing is case insensitive. 
 The returned formatter has a chronology of ISO set to ensure dates in other calendar systems are correctly converted. It has no override zone and uses the STRICT resolver style. /**
     * The ISO date-time formatter that formats or parses a date-time with an
     * offset, such as '2011-12-03T10:15:30+01:00'.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * the ISO-8601 extended offset date-time format.
     * The format consists of:
     * <ul>
     * <li>The {@link #ISO_LOCAL_DATE_TIME}
     * <li>The {@link ZoneOffset#getId() offset ID}. If the offset has seconds then
     *  they will be handled even though this is not part of the ISO-8601 standard.
     *  The offset parsing is lenient, which allows the minutes and seconds to be optional.
     *  Parsing is case insensitive.
     * </ul>
     * <p>
     * The returned formatter has a chronology of ISO set to ensure dates in
     * other calendar systems are correctly converted.
     * It has no override zone and uses the {@link ResolverStyle#STRICT STRICT} resolver style.
     */
    public static final DateTimeFormatter ISO_OFFSET_DATE_TIME;
    static {
        ISO_OFFSET_DATE_TIME = new DateTimeFormatterBuilder()
                .parseCaseInsensitive()
                .append(ISO_LOCAL_DATE_TIME)
                .parseLenient()
                .appendOffsetId()
                .parseStrict()
                .toFormatter(ResolverStyle.STRICT, IsoChronology.INSTANCE);
    }

    //-----------------------------------------------------------------------
    The ISO-like date-time formatter that formats or parses a date-time with
offset and zone, such as '2011-12-03T10:15:30+01:00[Europe/Paris]'.

This returns an immutable formatter capable of formatting and parsing
a format that extends the ISO-8601 extended offset date-time format
to add the time-zone.
The section in square brackets is not part of the ISO-8601 standard.
The format consists of:

The ISO_OFFSET_DATE_TIME 
If the zone ID is not available or is a ZoneOffset then the format is complete. 
An open square bracket '['.
The zone ID. This is not part of the ISO-8601 standard. Parsing is case sensitive. 
A close square bracket ']'.

 The returned formatter has a chronology of ISO set to ensure dates in other calendar systems are correctly converted. It has no override zone and uses the STRICT resolver style. /**
     * The ISO-like date-time formatter that formats or parses a date-time with
     * offset and zone, such as '2011-12-03T10:15:30+01:00[Europe/Paris]'.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * a format that extends the ISO-8601 extended offset date-time format
     * to add the time-zone.
     * The section in square brackets is not part of the ISO-8601 standard.
     * The format consists of:
     * <ul>
     * <li>The {@link #ISO_OFFSET_DATE_TIME}
     * <li>If the zone ID is not available or is a {@code ZoneOffset} then the format is complete.
     * <li>An open square bracket '['.
     * <li>The {@link ZoneId#getId() zone ID}. This is not part of the ISO-8601 standard.
     *  Parsing is case sensitive.
     * <li>A close square bracket ']'.
     * </ul>
     * <p>
     * The returned formatter has a chronology of ISO set to ensure dates in
     * other calendar systems are correctly converted.
     * It has no override zone and uses the {@link ResolverStyle#STRICT STRICT} resolver style.
     */
    public static final DateTimeFormatter ISO_ZONED_DATE_TIME;
    static {
        ISO_ZONED_DATE_TIME = new DateTimeFormatterBuilder()
                .append(ISO_OFFSET_DATE_TIME)
                .optionalStart()
                .appendLiteral('[')
                .parseCaseSensitive()
                .appendZoneRegionId()
                .appendLiteral(']')
                .toFormatter(ResolverStyle.STRICT, IsoChronology.INSTANCE);
    }

    //-----------------------------------------------------------------------
    The ISO-like date-time formatter that formats or parses a date-time with
the offset and zone if available, such as '2011-12-03T10:15:30',
'2011-12-03T10:15:30+01:00' or '2011-12-03T10:15:30+01:00[Europe/Paris]'.

This returns an immutable formatter capable of formatting and parsing
the ISO-8601 extended local or offset date-time format, as well as the
extended non-ISO form specifying the time-zone.
The format consists of:

The ISO_LOCAL_DATE_TIME 
If the offset is not available to format or parse then the format is complete.
The offset ID. If the offset has seconds then they will be handled even though this is not part of the ISO-8601 standard. 
If the zone ID is not available or is a ZoneOffset then the format is complete. 
An open square bracket '['.
The zone ID. This is not part of the ISO-8601 standard. Parsing is case sensitive. 
A close square bracket ']'.

 As this formatter has an optional element, it may be necessary to parse using parseBest. 
 The returned formatter has a chronology of ISO set to ensure dates in other calendar systems are correctly converted. It has no override zone and uses the STRICT resolver style. /**
     * The ISO-like date-time formatter that formats or parses a date-time with
     * the offset and zone if available, such as '2011-12-03T10:15:30',
     * '2011-12-03T10:15:30+01:00' or '2011-12-03T10:15:30+01:00[Europe/Paris]'.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * the ISO-8601 extended local or offset date-time format, as well as the
     * extended non-ISO form specifying the time-zone.
     * The format consists of:
     * <ul>
     * <li>The {@link #ISO_LOCAL_DATE_TIME}
     * <li>If the offset is not available to format or parse then the format is complete.
     * <li>The {@link ZoneOffset#getId() offset ID}. If the offset has seconds then
     *  they will be handled even though this is not part of the ISO-8601 standard.
     * <li>If the zone ID is not available or is a {@code ZoneOffset} then the format is complete.
     * <li>An open square bracket '['.
     * <li>The {@link ZoneId#getId() zone ID}. This is not part of the ISO-8601 standard.
     *  Parsing is case sensitive.
     * <li>A close square bracket ']'.
     * </ul>
     * <p>
     * As this formatter has an optional element, it may be necessary to parse using
     * {@link DateTimeFormatter#parseBest}.
     * <p>
     * The returned formatter has a chronology of ISO set to ensure dates in
     * other calendar systems are correctly converted.
     * It has no override zone and uses the {@link ResolverStyle#STRICT STRICT} resolver style.
     */
    public static final DateTimeFormatter ISO_DATE_TIME;
    static {
        ISO_DATE_TIME = new DateTimeFormatterBuilder()
                .append(ISO_LOCAL_DATE_TIME)
                .optionalStart()
                .appendOffsetId()
                .optionalStart()
                .appendLiteral('[')
                .parseCaseSensitive()
                .appendZoneRegionId()
                .appendLiteral(']')
                .toFormatter(ResolverStyle.STRICT, IsoChronology.INSTANCE);
    }

    //-----------------------------------------------------------------------
    The ISO date formatter that formats or parses the ordinal date
without an offset, such as '2012-337'.

This returns an immutable formatter capable of formatting and parsing
the ISO-8601 extended ordinal date format.
The format consists of:

Four digits or more for the year. Years in the range 0000 to 9999 will be pre-padded by zero to ensure four digits. Years outside that range will have a prefixed positive or negative symbol. 
A dash
Three digits for the day-of-year. This is pre-padded by zero to ensure three digits. 
If the offset is not available to format or parse then the format is complete.
The offset ID. If the offset has seconds then they will be handled even though this is not part of the ISO-8601 standard. Parsing is case insensitive. 
 As this formatter has an optional element, it may be necessary to parse using parseBest. 
 The returned formatter has a chronology of ISO set to ensure dates in other calendar systems are correctly converted. It has no override zone and uses the STRICT resolver style. /**
     * The ISO date formatter that formats or parses the ordinal date
     * without an offset, such as '2012-337'.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * the ISO-8601 extended ordinal date format.
     * The format consists of:
     * <ul>
     * <li>Four digits or more for the {@link ChronoField#YEAR year}.
     * Years in the range 0000 to 9999 will be pre-padded by zero to ensure four digits.
     * Years outside that range will have a prefixed positive or negative symbol.
     * <li>A dash
     * <li>Three digits for the {@link ChronoField#DAY_OF_YEAR day-of-year}.
     *  This is pre-padded by zero to ensure three digits.
     * <li>If the offset is not available to format or parse then the format is complete.
     * <li>The {@link ZoneOffset#getId() offset ID}. If the offset has seconds then
     *  they will be handled even though this is not part of the ISO-8601 standard.
     *  Parsing is case insensitive.
     * </ul>
     * <p>
     * As this formatter has an optional element, it may be necessary to parse using
     * {@link DateTimeFormatter#parseBest}.
     * <p>
     * The returned formatter has a chronology of ISO set to ensure dates in
     * other calendar systems are correctly converted.
     * It has no override zone and uses the {@link ResolverStyle#STRICT STRICT} resolver style.
     */
    public static final DateTimeFormatter ISO_ORDINAL_DATE;
    static {
        ISO_ORDINAL_DATE = new DateTimeFormatterBuilder()
                .parseCaseInsensitive()
                .appendValue(YEAR, 4, 10, SignStyle.EXCEEDS_PAD)
                .appendLiteral('-')
                .appendValue(DAY_OF_YEAR, 3)
                .optionalStart()
                .appendOffsetId()
                .toFormatter(ResolverStyle.STRICT, IsoChronology.INSTANCE);
    }

    //-----------------------------------------------------------------------
    The ISO date formatter that formats or parses the week-based date
without an offset, such as '2012-W48-6'.

This returns an immutable formatter capable of formatting and parsing
the ISO-8601 extended week-based date format.
The format consists of:

Four digits or more for the week-based-year. Years in the range 0000 to 9999 will be pre-padded by zero to ensure four digits. Years outside that range will have a prefixed positive or negative symbol. 
A dash
The letter 'W'. Parsing is case insensitive.
Two digits for the week-of-week-based-year. This is pre-padded by zero to ensure three digits. 
A dash
One digit for the day-of-week. The value run from Monday (1) to Sunday (7). 
If the offset is not available to format or parse then the format is complete.
The offset ID. If the offset has seconds then they will be handled even though this is not part of the ISO-8601 standard. Parsing is case insensitive. 
 As this formatter has an optional element, it may be necessary to parse using parseBest. 
 The returned formatter has a chronology of ISO set to ensure dates in other calendar systems are correctly converted. It has no override zone and uses the STRICT resolver style. /**
     * The ISO date formatter that formats or parses the week-based date
     * without an offset, such as '2012-W48-6'.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * the ISO-8601 extended week-based date format.
     * The format consists of:
     * <ul>
     * <li>Four digits or more for the {@link IsoFields#WEEK_BASED_YEAR week-based-year}.
     * Years in the range 0000 to 9999 will be pre-padded by zero to ensure four digits.
     * Years outside that range will have a prefixed positive or negative symbol.
     * <li>A dash
     * <li>The letter 'W'. Parsing is case insensitive.
     * <li>Two digits for the {@link IsoFields#WEEK_OF_WEEK_BASED_YEAR week-of-week-based-year}.
     *  This is pre-padded by zero to ensure three digits.
     * <li>A dash
     * <li>One digit for the {@link ChronoField#DAY_OF_WEEK day-of-week}.
     *  The value run from Monday (1) to Sunday (7).
     * <li>If the offset is not available to format or parse then the format is complete.
     * <li>The {@link ZoneOffset#getId() offset ID}. If the offset has seconds then
     *  they will be handled even though this is not part of the ISO-8601 standard.
     *  Parsing is case insensitive.
     * </ul>
     * <p>
     * As this formatter has an optional element, it may be necessary to parse using
     * {@link DateTimeFormatter#parseBest}.
     * <p>
     * The returned formatter has a chronology of ISO set to ensure dates in
     * other calendar systems are correctly converted.
     * It has no override zone and uses the {@link ResolverStyle#STRICT STRICT} resolver style.
     */
    public static final DateTimeFormatter ISO_WEEK_DATE;
    static {
        ISO_WEEK_DATE = new DateTimeFormatterBuilder()
                .parseCaseInsensitive()
                .appendValue(IsoFields.WEEK_BASED_YEAR, 4, 10, SignStyle.EXCEEDS_PAD)
                .appendLiteral("-W")
                .appendValue(IsoFields.WEEK_OF_WEEK_BASED_YEAR, 2)
                .appendLiteral('-')
                .appendValue(DAY_OF_WEEK, 1)
                .optionalStart()
                .appendOffsetId()
                .toFormatter(ResolverStyle.STRICT, IsoChronology.INSTANCE);
    }

    //-----------------------------------------------------------------------
    The ISO instant formatter that formats or parses an instant in UTC,
such as '2011-12-03T10:15:30Z'.

This returns an immutable formatter capable of formatting and parsing
the ISO-8601 instant format.
When formatting, the second-of-minute is always output.
The nano-of-second outputs zero, three, six or nine digits as necessary.
When parsing, time to at least the seconds field is required.
Fractional seconds from zero to nine are parsed.
The localized decimal style is not used.
 This is a special case formatter intended to allow a human readable form of an Instant. The Instant class is designed to only represent a point in time and internally stores a value in nanoseconds from a fixed epoch of 1970-01-01Z. As such, an Instant cannot be formatted as a date or time without providing some form of time-zone. This formatter allows the Instant to be formatted, by providing a suitable conversion using ZoneOffset.UTC. 

The format consists of:

The ISO_OFFSET_DATE_TIME where the instant is converted from ChronoField.INSTANT_SECONDS and ChronoField.NANO_OF_SECOND using the UTC offset. Parsing is case insensitive. 
 The returned formatter has no override chronology or zone. It uses the STRICT resolver style. /**
     * The ISO instant formatter that formats or parses an instant in UTC,
     * such as '2011-12-03T10:15:30Z'.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * the ISO-8601 instant format.
     * When formatting, the second-of-minute is always output.
     * The nano-of-second outputs zero, three, six or nine digits as necessary.
     * When parsing, time to at least the seconds field is required.
     * Fractional seconds from zero to nine are parsed.
     * The localized decimal style is not used.
     * <p>
     * This is a special case formatter intended to allow a human readable form
     * of an {@link java.time.Instant}. The {@code Instant} class is designed to
     * only represent a point in time and internally stores a value in nanoseconds
     * from a fixed epoch of 1970-01-01Z. As such, an {@code Instant} cannot be
     * formatted as a date or time without providing some form of time-zone.
     * This formatter allows the {@code Instant} to be formatted, by providing
     * a suitable conversion using {@code ZoneOffset.UTC}.
     * <p>
     * The format consists of:
     * <ul>
     * <li>The {@link #ISO_OFFSET_DATE_TIME} where the instant is converted from
     *  {@link ChronoField#INSTANT_SECONDS} and {@link ChronoField#NANO_OF_SECOND}
     *  using the {@code UTC} offset. Parsing is case insensitive.
     * </ul>
     * <p>
     * The returned formatter has no override chronology or zone.
     * It uses the {@link ResolverStyle#STRICT STRICT} resolver style.
     */
    public static final DateTimeFormatter ISO_INSTANT;
    static {
        ISO_INSTANT = new DateTimeFormatterBuilder()
                .parseCaseInsensitive()
                .appendInstant()
                .toFormatter(ResolverStyle.STRICT, null);
    }

    //-----------------------------------------------------------------------
    The ISO date formatter that formats or parses a date without an
offset, such as '20111203'.

This returns an immutable formatter capable of formatting and parsing
the ISO-8601 basic local date format.
The format consists of:

Four digits for the year. Only years in the range 0000 to 9999 are supported. 
Two digits for the month-of-year. This is pre-padded by zero to ensure two digits. 
Two digits for the day-of-month. This is pre-padded by zero to ensure two digits. 
If the offset is not available to format or parse then the format is complete.
The offset ID without colons. If the offset has seconds then they will be handled even though this is not part of the ISO-8601 standard. The offset parsing is lenient, which allows the minutes and seconds to be optional. Parsing is case insensitive. 
 As this formatter has an optional element, it may be necessary to parse using parseBest. 
 The returned formatter has a chronology of ISO set to ensure dates in other calendar systems are correctly converted. It has no override zone and uses the STRICT resolver style. /**
     * The ISO date formatter that formats or parses a date without an
     * offset, such as '20111203'.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * the ISO-8601 basic local date format.
     * The format consists of:
     * <ul>
     * <li>Four digits for the {@link ChronoField#YEAR year}.
     *  Only years in the range 0000 to 9999 are supported.
     * <li>Two digits for the {@link ChronoField#MONTH_OF_YEAR month-of-year}.
     *  This is pre-padded by zero to ensure two digits.
     * <li>Two digits for the {@link ChronoField#DAY_OF_MONTH day-of-month}.
     *  This is pre-padded by zero to ensure two digits.
     * <li>If the offset is not available to format or parse then the format is complete.
     * <li>The {@link ZoneOffset#getId() offset ID} without colons. If the offset has
     *  seconds then they will be handled even though this is not part of the ISO-8601 standard.
     *  The offset parsing is lenient, which allows the minutes and seconds to be optional.
     *  Parsing is case insensitive.
     * </ul>
     * <p>
     * As this formatter has an optional element, it may be necessary to parse using
     * {@link DateTimeFormatter#parseBest}.
     * <p>
     * The returned formatter has a chronology of ISO set to ensure dates in
     * other calendar systems are correctly converted.
     * It has no override zone and uses the {@link ResolverStyle#STRICT STRICT} resolver style.
     */
    public static final DateTimeFormatter BASIC_ISO_DATE;
    static {
        BASIC_ISO_DATE = new DateTimeFormatterBuilder()
                .parseCaseInsensitive()
                .appendValue(YEAR, 4)
                .appendValue(MONTH_OF_YEAR, 2)
                .appendValue(DAY_OF_MONTH, 2)
                .optionalStart()
                .parseLenient()
                .appendOffset("+HHMMss", "Z")
                .parseStrict()
                .toFormatter(ResolverStyle.STRICT, IsoChronology.INSTANCE);
    }

    //-----------------------------------------------------------------------
    The RFC-1123 date-time formatter, such as 'Tue, 3 Jun 2008 11:05:30 GMT'.

This returns an immutable formatter capable of formatting and parsing
most of the RFC-1123 format.
RFC-1123 updates RFC-822 changing the year from two digits to four.
This implementation requires a four digit year.
This implementation also does not handle North American or military zone
names, only 'GMT' and offset amounts.

The format consists of:

If the day-of-week is not available to format or parse then jump to day-of-month.
Three letter day-of-week in English. 
A comma
A space
One or two digits for the day-of-month. 
A space
Three letter month-of-year in English. 
A space
Four digits for the year. Only years in the range 0000 to 9999 are supported. 
A space
Two digits for the hour-of-day. This is pre-padded by zero to ensure two digits. 
A colon
Two digits for the minute-of-hour. This is pre-padded by zero to ensure two digits. 
If the second-of-minute is not available then jump to the next space.
A colon
Two digits for the second-of-minute. This is pre-padded by zero to ensure two digits. 
A space
The offset ID without colons or seconds. An offset of zero uses "GMT". North American zone names and military zone names are not handled. 

Parsing is case insensitive.
 The returned formatter has a chronology of ISO set to ensure dates in other calendar systems are correctly converted. It has no override zone and uses the SMART resolver style. /**
     * The RFC-1123 date-time formatter, such as 'Tue, 3 Jun 2008 11:05:30 GMT'.
     * <p>
     * This returns an immutable formatter capable of formatting and parsing
     * most of the RFC-1123 format.
     * RFC-1123 updates RFC-822 changing the year from two digits to four.
     * This implementation requires a four digit year.
     * This implementation also does not handle North American or military zone
     * names, only 'GMT' and offset amounts.
     * <p>
     * The format consists of:
     * <ul>
     * <li>If the day-of-week is not available to format or parse then jump to day-of-month.
     * <li>Three letter {@link ChronoField#DAY_OF_WEEK day-of-week} in English.
     * <li>A comma
     * <li>A space
     * <li>One or two digits for the {@link ChronoField#DAY_OF_MONTH day-of-month}.
     * <li>A space
     * <li>Three letter {@link ChronoField#MONTH_OF_YEAR month-of-year} in English.
     * <li>A space
     * <li>Four digits for the {@link ChronoField#YEAR year}.
     *  Only years in the range 0000 to 9999 are supported.
     * <li>A space
     * <li>Two digits for the {@link ChronoField#HOUR_OF_DAY hour-of-day}.
     *  This is pre-padded by zero to ensure two digits.
     * <li>A colon
     * <li>Two digits for the {@link ChronoField#MINUTE_OF_HOUR minute-of-hour}.
     *  This is pre-padded by zero to ensure two digits.
     * <li>If the second-of-minute is not available then jump to the next space.
     * <li>A colon
     * <li>Two digits for the {@link ChronoField#SECOND_OF_MINUTE second-of-minute}.
     *  This is pre-padded by zero to ensure two digits.
     * <li>A space
     * <li>The {@link ZoneOffset#getId() offset ID} without colons or seconds.
     *  An offset of zero uses "GMT". North American zone names and military zone names are not handled.
     * </ul>
     * <p>
     * Parsing is case insensitive.
     * <p>
     * The returned formatter has a chronology of ISO set to ensure dates in
     * other calendar systems are correctly converted.
     * It has no override zone and uses the {@link ResolverStyle#SMART SMART} resolver style.
     */
    public static final DateTimeFormatter RFC_1123_DATE_TIME;
    static {
        // manually code maps to ensure correct data always used
        // (locale data can be changed by application code)
        Map<Long, String> dow = new HashMap<>();
        dow.put(1L, "Mon");
        dow.put(2L, "Tue");
        dow.put(3L, "Wed");
        dow.put(4L, "Thu");
        dow.put(5L, "Fri");
        dow.put(6L, "Sat");
        dow.put(7L, "Sun");
        Map<Long, String> moy = new HashMap<>();
        moy.put(1L, "Jan");
        moy.put(2L, "Feb");
        moy.put(3L, "Mar");
        moy.put(4L, "Apr");
        moy.put(5L, "May");
        moy.put(6L, "Jun");
        moy.put(7L, "Jul");
        moy.put(8L, "Aug");
        moy.put(9L, "Sep");
        moy.put(10L, "Oct");
        moy.put(11L, "Nov");
        moy.put(12L, "Dec");
        RFC_1123_DATE_TIME = new DateTimeFormatterBuilder()
                .parseCaseInsensitive()
                .parseLenient()
                .optionalStart()
                .appendText(DAY_OF_WEEK, dow)
                .appendLiteral(", ")
                .optionalEnd()
                .appendValue(DAY_OF_MONTH, 1, 2, SignStyle.NOT_NEGATIVE)
                .appendLiteral(' ')
                .appendText(MONTH_OF_YEAR, moy)
                .appendLiteral(' ')
                .appendValue(YEAR, 4)  // 2 digit year not handled
                .appendLiteral(' ')
                .appendValue(HOUR_OF_DAY, 2)
                .appendLiteral(':')
                .appendValue(MINUTE_OF_HOUR, 2)
                .optionalStart()
                .appendLiteral(':')
                .appendValue(SECOND_OF_MINUTE, 2)
                .optionalEnd()
                .appendLiteral(' ')
                .appendOffset("+HHMM", "GMT")  // should handle UT/Z/EST/EDT/CST/CDT/MST/MDT/PST/MDT
                .toFormatter(ResolverStyle.SMART, IsoChronology.INSTANCE);
    }

    //-----------------------------------------------------------------------
    A query that provides access to the excess days that were parsed.
 This returns a singleton query that provides access to additional information from the parse. The query always returns a non-null period, with a zero period returned instead of null. 

There are two situations where this query may return a non-zero period.

If the ResolverStyle is LENIENT and a time is parsed without a date, then the complete result of the parse consists of a LocalTime and an excess Period in days. 
If the ResolverStyle is SMART and a time is parsed without a date where the time is 24:00:00, then the complete result of the parse consists of a LocalTime of 00:00:00 and an excess Period of one day. 
 In both cases, if a complete ChronoLocalDateTime or Instant is parsed, then the excess days are added to the date part. As a result, this query will return a zero period. 
 The SMART behaviour handles the common "end of day" 24:00 value. Processing in LENIENT mode also produces the same result: 
 Text to parse        Parsed object                         Excess days
 "2012-12-03T00:00"   LocalDateTime.of(2012, 12, 3, 0, 0)   ZERO
 "2012-12-03T24:00"   LocalDateTime.of(2012, 12, 4, 0, 0)   ZERO
 "00:00"              LocalTime.of(0, 0)                    ZERO
 "24:00"              LocalTime.of(0, 0)                    Period.ofDays(1)

The query can be used as follows:
 TemporalAccessor parsed = formatter.parse(str);
 LocalTime time = parsed.query(LocalTime::from);
 Period extraDays = parsed.query(DateTimeFormatter.parsedExcessDays());

Returns: a query that provides access to the excess days that were parsed/**
     * A query that provides access to the excess days that were parsed.
     * <p>
     * This returns a singleton {@linkplain TemporalQuery query} that provides
     * access to additional information from the parse. The query always returns
     * a non-null period, with a zero period returned instead of null.
     * <p>
     * There are two situations where this query may return a non-zero period.
     * <ul>
     * <li>If the {@code ResolverStyle} is {@code LENIENT} and a time is parsed
     *  without a date, then the complete result of the parse consists of a
     *  {@code LocalTime} and an excess {@code Period} in days.
     *
     * <li>If the {@code ResolverStyle} is {@code SMART} and a time is parsed
     *  without a date where the time is 24:00:00, then the complete result of
     *  the parse consists of a {@code LocalTime} of 00:00:00 and an excess
     *  {@code Period} of one day.
     * </ul>
     * <p>
     * In both cases, if a complete {@code ChronoLocalDateTime} or {@code Instant}
     * is parsed, then the excess days are added to the date part.
     * As a result, this query will return a zero period.
     * <p>
     * The {@code SMART} behaviour handles the common "end of day" 24:00 value.
     * Processing in {@code LENIENT} mode also produces the same result:
     * <pre>
     *  Text to parse        Parsed object                         Excess days
     *  "2012-12-03T00:00"   LocalDateTime.of(2012, 12, 3, 0, 0)   ZERO
     *  "2012-12-03T24:00"   LocalDateTime.of(2012, 12, 4, 0, 0)   ZERO
     *  "00:00"              LocalTime.of(0, 0)                    ZERO
     *  "24:00"              LocalTime.of(0, 0)                    Period.ofDays(1)
     * </pre>
     * The query can be used as follows:
     * <pre>
     *  TemporalAccessor parsed = formatter.parse(str);
     *  LocalTime time = parsed.query(LocalTime::from);
     *  Period extraDays = parsed.query(DateTimeFormatter.parsedExcessDays());
     * </pre>
     * @return a query that provides access to the excess days that were parsed
     */
    public static final TemporalQuery<Period> parsedExcessDays() {
        return PARSED_EXCESS_DAYS;
    }
    private static final TemporalQuery<Period> PARSED_EXCESS_DAYS = t -> {
        if (t instanceof Parsed) {
            return ((Parsed) t).excessDays;
        } else {
            return Period.ZERO;
        }
    };

    A query that provides access to whether a leap-second was parsed.
 This returns a singleton query that provides access to additional information from the parse. The query always returns a non-null boolean, true if parsing saw a leap-second, false if not. 
 Instant parsing handles the special "leap second" time of '23:59:60'. Leap seconds occur at '23:59:60' in the UTC time-zone, but at other local times in different time-zones. To avoid this potential ambiguity, the handling of leap-seconds is limited to DateTimeFormatterBuilder.appendInstant(), as that method always parses the instant with the UTC zone offset. 
 If the time '23:59:60' is received, then a simple conversion is applied, replacing the second-of-minute of 60 with 59. This query can be used on the parse result to determine if the leap-second adjustment was made. The query will return true if it did adjust to remove the leap-second, and false if not. Note that applying a leap-second smoothing mechanism, such as UTC-SLS, is the responsibility of the application, as follows: 
 TemporalAccessor parsed = formatter.parse(str);
 Instant instant = parsed.query(Instant::from);
 if (parsed.query(DateTimeFormatter.parsedLeapSecond())) {
   // validate leap-second is correct and apply correct smoothing
 }

Returns: a query that provides access to whether a leap-second was parsed/**
     * A query that provides access to whether a leap-second was parsed.
     * <p>
     * This returns a singleton {@linkplain TemporalQuery query} that provides
     * access to additional information from the parse. The query always returns
     * a non-null boolean, true if parsing saw a leap-second, false if not.
     * <p>
     * Instant parsing handles the special "leap second" time of '23:59:60'.
     * Leap seconds occur at '23:59:60' in the UTC time-zone, but at other
     * local times in different time-zones. To avoid this potential ambiguity,
     * the handling of leap-seconds is limited to
     * {@link DateTimeFormatterBuilder#appendInstant()}, as that method
     * always parses the instant with the UTC zone offset.
     * <p>
     * If the time '23:59:60' is received, then a simple conversion is applied,
     * replacing the second-of-minute of 60 with 59. This query can be used
     * on the parse result to determine if the leap-second adjustment was made.
     * The query will return {@code true} if it did adjust to remove the
     * leap-second, and {@code false} if not. Note that applying a leap-second
     * smoothing mechanism, such as UTC-SLS, is the responsibility of the
     * application, as follows:
     * <pre>
     *  TemporalAccessor parsed = formatter.parse(str);
     *  Instant instant = parsed.query(Instant::from);
     *  if (parsed.query(DateTimeFormatter.parsedLeapSecond())) {
     *    // validate leap-second is correct and apply correct smoothing
     *  }
     * </pre>
     * @return a query that provides access to whether a leap-second was parsed
     */
    public static final TemporalQuery<Boolean> parsedLeapSecond() {
        return PARSED_LEAP_SECOND;
    }
    private static final TemporalQuery<Boolean> PARSED_LEAP_SECOND = t -> {
        if (t instanceof Parsed) {
            return ((Parsed) t).leapSecond;
        } else {
            return Boolean.FALSE;
        }
    };

    //-----------------------------------------------------------------------
    Constructor.
Params: printerParser –  the printer/parser to use, not null
locale –  the locale to use, not null
decimalStyle –  the DecimalStyle to use, not null
resolverStyle –  the resolver style to use, not null
resolverFields –  the fields to use during resolving, null for all fields
chrono –  the chronology to use, null for no override
zone –  the zone to use, null for no override/**
     * Constructor.
     *
     * @param printerParser  the printer/parser to use, not null
     * @param locale  the locale to use, not null
     * @param decimalStyle  the DecimalStyle to use, not null
     * @param resolverStyle  the resolver style to use, not null
     * @param resolverFields  the fields to use during resolving, null for all fields
     * @param chrono  the chronology to use, null for no override
     * @param zone  the zone to use, null for no override
     */
    DateTimeFormatter(CompositePrinterParser printerParser,
            Locale locale, DecimalStyle decimalStyle,
            ResolverStyle resolverStyle, Set<TemporalField> resolverFields,
            Chronology chrono, ZoneId zone) {
        this.printerParser = Objects.requireNonNull(printerParser, "printerParser");
        this.resolverFields = resolverFields;
        this.locale = Objects.requireNonNull(locale, "locale");
        this.decimalStyle = Objects.requireNonNull(decimalStyle, "decimalStyle");
        this.resolverStyle = Objects.requireNonNull(resolverStyle, "resolverStyle");
        this.chrono = chrono;
        this.zone = zone;
    }

    //-----------------------------------------------------------------------
    Gets the locale to be used during formatting.

This is used to lookup any part of the formatter needing specific
localization, such as the text or localized pattern.
Returns: the locale of this formatter, not null/**
     * Gets the locale to be used during formatting.
     * <p>
     * This is used to lookup any part of the formatter needing specific
     * localization, such as the text or localized pattern.
     *
     * @return the locale of this formatter, not null
     */
    public Locale getLocale() {
        return locale;
    }

    Returns a copy of this formatter with a new locale.

This is used to lookup any part of the formatter needing specific
localization, such as the text or localized pattern.

The locale is stored as passed in, without further processing.
If the locale has 
Unicode extensions, they may be used later in text processing. To set the chronology, time-zone and decimal style from unicode extensions, see localizedBy(). 

This instance is immutable and unaffected by this method call.
Params: locale –  the new locale, not null
See Also: localizedBy(Locale)
Returns: a formatter based on this formatter with the requested locale, not null/**
     * Returns a copy of this formatter with a new locale.
     * <p>
     * This is used to lookup any part of the formatter needing specific
     * localization, such as the text or localized pattern.
     * <p>
     * The locale is stored as passed in, without further processing.
     * If the locale has <a href="../../util/Locale.html#def_locale_extension">
     * Unicode extensions</a>, they may be used later in text
     * processing. To set the chronology, time-zone and decimal style from
     * unicode extensions, see {@link #localizedBy localizedBy()}.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param locale  the new locale, not null
     * @return a formatter based on this formatter with the requested locale, not null
     * @see #localizedBy(Locale)
     */
    public DateTimeFormatter withLocale(Locale locale) {
        if (this.locale.equals(locale)) {
            return this;
        }
        return new DateTimeFormatter(printerParser, locale, decimalStyle, resolverStyle, resolverFields, chrono, zone);
    }

    Returns a copy of this formatter with localized values of the locale,
calendar, region, decimal style and/or timezone, that supercede values in
this formatter.

This is used to lookup any part of the formatter needing specific
localization, such as the text or localized pattern. If the locale contains the
"ca" (calendar), "nu" (numbering system), "rg" (region override), and/or
"tz" (timezone)
Unicode extensions,
the chronology, numbering system and/or the zone are overridden. If both "ca"
and "rg" are specified, the chronology from the "ca" extension supersedes the
implicit one from the "rg" extension. Same is true for the "nu" extension.
 Unlike the withLocale method, the call to this method may produce a different formatter depending on the order of method chaining with other withXXXX() methods. 

This instance is immutable and unaffected by this method call.
Params: locale –  the locale, not null
See Also: withLocale(Locale)
Returns: a formatter based on this formatter with localized values of
     the calendar, decimal style and/or timezone, that supercede values in this
     formatter.
Since: 10/**
     * Returns a copy of this formatter with localized values of the locale,
     * calendar, region, decimal style and/or timezone, that supercede values in
     * this formatter.
     * <p>
     * This is used to lookup any part of the formatter needing specific
     * localization, such as the text or localized pattern. If the locale contains the
     * "ca" (calendar), "nu" (numbering system), "rg" (region override), and/or
     * "tz" (timezone)
     * <a href="../../util/Locale.html#def_locale_extension">Unicode extensions</a>,
     * the chronology, numbering system and/or the zone are overridden. If both "ca"
     * and "rg" are specified, the chronology from the "ca" extension supersedes the
     * implicit one from the "rg" extension. Same is true for the "nu" extension.
     * <p>
     * Unlike the {@link #withLocale withLocale} method, the call to this method may
     * produce a different formatter depending on the order of method chaining with
     * other withXXXX() methods.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param locale  the locale, not null
     * @return a formatter based on this formatter with localized values of
     *      the calendar, decimal style and/or timezone, that supercede values in this
     *      formatter.
     * @see #withLocale(Locale)
     * @since 10
     */
    public DateTimeFormatter localizedBy(Locale locale) {
        if (this.locale.equals(locale)) {
            return this;
        }

        // Check for decimalStyle/chronology/timezone in locale object
        Chronology c = locale.getUnicodeLocaleType("ca") != null ?
                       Chronology.ofLocale(locale) : chrono;
        DecimalStyle ds = locale.getUnicodeLocaleType("nu") != null ?
                       DecimalStyle.of(locale) : decimalStyle;
        String tzType = locale.getUnicodeLocaleType("tz");
        ZoneId z  = tzType != null ?
                    TimeZoneNameUtility.convertLDMLShortID(tzType)
                        .map(ZoneId::of)
                        .orElse(zone) :
                    zone;
        return new DateTimeFormatter(printerParser, locale, ds, resolverStyle, resolverFields, c, z);
    }

    //-----------------------------------------------------------------------
    Gets the DecimalStyle to be used during formatting.
Returns: the locale of this formatter, not null/**
     * Gets the DecimalStyle to be used during formatting.
     *
     * @return the locale of this formatter, not null
     */
    public DecimalStyle getDecimalStyle() {
        return decimalStyle;
    }

    Returns a copy of this formatter with a new DecimalStyle.

This instance is immutable and unaffected by this method call.
Params: decimalStyle –  the new DecimalStyle, not null
Returns: a formatter based on this formatter with the requested DecimalStyle, not null/**
     * Returns a copy of this formatter with a new DecimalStyle.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param decimalStyle  the new DecimalStyle, not null
     * @return a formatter based on this formatter with the requested DecimalStyle, not null
     */
    public DateTimeFormatter withDecimalStyle(DecimalStyle decimalStyle) {
        if (this.decimalStyle.equals(decimalStyle)) {
            return this;
        }
        return new DateTimeFormatter(printerParser, locale, decimalStyle, resolverStyle, resolverFields, chrono, zone);
    }

    //-----------------------------------------------------------------------
    Gets the overriding chronology to be used during formatting.
 This returns the override chronology, used to convert dates. By default, a formatter has no override chronology, returning null. See withChronology(Chronology) for more details on overriding. 
Returns: the override chronology of this formatter, null if no override/**
     * Gets the overriding chronology to be used during formatting.
     * <p>
     * This returns the override chronology, used to convert dates.
     * By default, a formatter has no override chronology, returning null.
     * See {@link #withChronology(Chronology)} for more details on overriding.
     *
     * @return the override chronology of this formatter, null if no override
     */
    public Chronology getChronology() {
        return chrono;
    }

    Returns a copy of this formatter with a new override chronology.

This returns a formatter with similar state to this formatter but
with the override chronology set.
By default, a formatter has no override chronology, returning null.

If an override is added, then any date that is formatted or parsed will be affected.
 When formatting, if the temporal object contains a date, then it will be converted to a date in the override chronology. Whether the temporal contains a date is determined by querying the EPOCH_DAY field. Any time or zone will be retained unaltered unless overridden. 
 If the temporal object does not contain a date, but does contain one or more ChronoField date fields, then a DateTimeException is thrown. In all other cases, the override chronology is added to the temporal, replacing any previous chronology, but without changing the date/time. 
 When parsing, there are two distinct cases to consider. If a chronology has been parsed directly from the text, perhaps because DateTimeFormatterBuilder.appendChronologyId() was used, then this override chronology has no effect. If no zone has been parsed, then this override chronology will be used to interpret the ChronoField values into a date according to the date resolving rules of the chronology. 

This instance is immutable and unaffected by this method call.
Params: chrono –  the new chronology, null if no override
Returns: a formatter based on this formatter with the requested override chronology, not null/**
     * Returns a copy of this formatter with a new override chronology.
     * <p>
     * This returns a formatter with similar state to this formatter but
     * with the override chronology set.
     * By default, a formatter has no override chronology, returning null.
     * <p>
     * If an override is added, then any date that is formatted or parsed will be affected.
     * <p>
     * When formatting, if the temporal object contains a date, then it will
     * be converted to a date in the override chronology.
     * Whether the temporal contains a date is determined by querying the
     * {@link ChronoField#EPOCH_DAY EPOCH_DAY} field.
     * Any time or zone will be retained unaltered unless overridden.
     * <p>
     * If the temporal object does not contain a date, but does contain one
     * or more {@code ChronoField} date fields, then a {@code DateTimeException}
     * is thrown. In all other cases, the override chronology is added to the temporal,
     * replacing any previous chronology, but without changing the date/time.
     * <p>
     * When parsing, there are two distinct cases to consider.
     * If a chronology has been parsed directly from the text, perhaps because
     * {@link DateTimeFormatterBuilder#appendChronologyId()} was used, then
     * this override chronology has no effect.
     * If no zone has been parsed, then this override chronology will be used
     * to interpret the {@code ChronoField} values into a date according to the
     * date resolving rules of the chronology.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param chrono  the new chronology, null if no override
     * @return a formatter based on this formatter with the requested override chronology, not null
     */
    public DateTimeFormatter withChronology(Chronology chrono) {
        if (Objects.equals(this.chrono, chrono)) {
            return this;
        }
        return new DateTimeFormatter(printerParser, locale, decimalStyle, resolverStyle, resolverFields, chrono, zone);
    }

    //-----------------------------------------------------------------------
    Gets the overriding zone to be used during formatting.
 This returns the override zone, used to convert instants. By default, a formatter has no override zone, returning null. See withZone(ZoneId) for more details on overriding. 
Returns: the override zone of this formatter, null if no override/**
     * Gets the overriding zone to be used during formatting.
     * <p>
     * This returns the override zone, used to convert instants.
     * By default, a formatter has no override zone, returning null.
     * See {@link #withZone(ZoneId)} for more details on overriding.
     *
     * @return the override zone of this formatter, null if no override
     */
    public ZoneId getZone() {
        return zone;
    }

    Returns a copy of this formatter with a new override zone.

This returns a formatter with similar state to this formatter but
with the override zone set.
By default, a formatter has no override zone, returning null.

If an override is added, then any instant that is formatted or parsed will be affected.
 When formatting, if the temporal object contains an instant, then it will be converted to a zoned date-time using the override zone. Whether the temporal is an instant is determined by querying the INSTANT_SECONDS field. If the input has a chronology then it will be retained unless overridden. If the input does not have a chronology, such as Instant, then the ISO chronology will be used. 
 If the temporal object does not contain an instant, but does contain an offset then an additional check is made. If the normalized override zone is an offset that differs from the offset of the temporal, then a DateTimeException is thrown. In all other cases, the override zone is added to the temporal, replacing any previous zone, but without changing the date/time. 
 When parsing, there are two distinct cases to consider. If a zone has been parsed directly from the text, perhaps because DateTimeFormatterBuilder.appendZoneId() was used, then this override zone has no effect. If no zone has been parsed, then this override zone will be included in the result of the parse where it can be used to build instants and date-times. 

This instance is immutable and unaffected by this method call.
Params: zone –  the new override zone, null if no override
Returns: a formatter based on this formatter with the requested override zone, not null/**
     * Returns a copy of this formatter with a new override zone.
     * <p>
     * This returns a formatter with similar state to this formatter but
     * with the override zone set.
     * By default, a formatter has no override zone, returning null.
     * <p>
     * If an override is added, then any instant that is formatted or parsed will be affected.
     * <p>
     * When formatting, if the temporal object contains an instant, then it will
     * be converted to a zoned date-time using the override zone.
     * Whether the temporal is an instant is determined by querying the
     * {@link ChronoField#INSTANT_SECONDS INSTANT_SECONDS} field.
     * If the input has a chronology then it will be retained unless overridden.
     * If the input does not have a chronology, such as {@code Instant}, then
     * the ISO chronology will be used.
     * <p>
     * If the temporal object does not contain an instant, but does contain
     * an offset then an additional check is made. If the normalized override
     * zone is an offset that differs from the offset of the temporal, then
     * a {@code DateTimeException} is thrown. In all other cases, the override
     * zone is added to the temporal, replacing any previous zone, but without
     * changing the date/time.
     * <p>
     * When parsing, there are two distinct cases to consider.
     * If a zone has been parsed directly from the text, perhaps because
     * {@link DateTimeFormatterBuilder#appendZoneId()} was used, then
     * this override zone has no effect.
     * If no zone has been parsed, then this override zone will be included in
     * the result of the parse where it can be used to build instants and date-times.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param zone  the new override zone, null if no override
     * @return a formatter based on this formatter with the requested override zone, not null
     */
    public DateTimeFormatter withZone(ZoneId zone) {
        if (Objects.equals(this.zone, zone)) {
            return this;
        }
        return new DateTimeFormatter(printerParser, locale, decimalStyle, resolverStyle, resolverFields, chrono, zone);
    }

    //-----------------------------------------------------------------------
    Gets the resolver style to use during parsing.
 This returns the resolver style, used during the second phase of parsing when fields are resolved into dates and times. By default, a formatter has the SMART resolver style. See withResolverStyle(ResolverStyle) for more details. 
Returns: the resolver style of this formatter, not null/**
     * Gets the resolver style to use during parsing.
     * <p>
     * This returns the resolver style, used during the second phase of parsing
     * when fields are resolved into dates and times.
     * By default, a formatter has the {@link ResolverStyle#SMART SMART} resolver style.
     * See {@link #withResolverStyle(ResolverStyle)} for more details.
     *
     * @return the resolver style of this formatter, not null
     */
    public ResolverStyle getResolverStyle() {
        return resolverStyle;
    }

    Returns a copy of this formatter with a new resolver style.
 This returns a formatter with similar state to this formatter but with the resolver style set. By default, a formatter has the SMART resolver style. 
 Changing the resolver style only has an effect during parsing. Parsing a text string occurs in two phases. Phase 1 is a basic text parse according to the fields added to the builder. Phase 2 resolves the parsed field-value pairs into date and/or time objects. The resolver style is used to control how phase 2, resolving, happens. See ResolverStyle for more information on the options available. 

This instance is immutable and unaffected by this method call.
Params: resolverStyle –  the new resolver style, not null
Returns: a formatter based on this formatter with the requested resolver style, not null/**
     * Returns a copy of this formatter with a new resolver style.
     * <p>
     * This returns a formatter with similar state to this formatter but
     * with the resolver style set. By default, a formatter has the
     * {@link ResolverStyle#SMART SMART} resolver style.
     * <p>
     * Changing the resolver style only has an effect during parsing.
     * Parsing a text string occurs in two phases.
     * Phase 1 is a basic text parse according to the fields added to the builder.
     * Phase 2 resolves the parsed field-value pairs into date and/or time objects.
     * The resolver style is used to control how phase 2, resolving, happens.
     * See {@code ResolverStyle} for more information on the options available.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param resolverStyle  the new resolver style, not null
     * @return a formatter based on this formatter with the requested resolver style, not null
     */
    public DateTimeFormatter withResolverStyle(ResolverStyle resolverStyle) {
        Objects.requireNonNull(resolverStyle, "resolverStyle");
        if (Objects.equals(this.resolverStyle, resolverStyle)) {
            return this;
        }
        return new DateTimeFormatter(printerParser, locale, decimalStyle, resolverStyle, resolverFields, chrono, zone);
    }

    //-----------------------------------------------------------------------
    Gets the resolver fields to use during parsing.
 This returns the resolver fields, used during the second phase of parsing when fields are resolved into dates and times. By default, a formatter has no resolver fields, and thus returns null. See withResolverFields(Set<TemporalField>) for more details. 
Returns: the immutable set of resolver fields of this formatter, null if no fields/**
     * Gets the resolver fields to use during parsing.
     * <p>
     * This returns the resolver fields, used during the second phase of parsing
     * when fields are resolved into dates and times.
     * By default, a formatter has no resolver fields, and thus returns null.
     * See {@link #withResolverFields(Set)} for more details.
     *
     * @return the immutable set of resolver fields of this formatter, null if no fields
     */
    public Set<TemporalField> getResolverFields() {
        return resolverFields;
    }

    Returns a copy of this formatter with a new set of resolver fields.

This returns a formatter with similar state to this formatter but with
the resolver fields set. By default, a formatter has no resolver fields.

Changing the resolver fields only has an effect during parsing.
Parsing a text string occurs in two phases.
Phase 1 is a basic text parse according to the fields added to the builder.
Phase 2 resolves the parsed field-value pairs into date and/or time objects.
The resolver fields are used to filter the field-value pairs between phase 1 and 2.
 This can be used to select between two or more ways that a date or time might be resolved. For example, if the formatter consists of year, month, day-of-month and day-of-year, then there are two ways to resolve a date. Calling this method with the arguments YEAR and DAY_OF_YEAR will ensure that the date is resolved using the year and day-of-year, effectively meaning that the month and day-of-month are ignored during the resolving phase. 
 In a similar manner, this method can be used to ignore secondary fields that would otherwise be cross-checked. For example, if the formatter consists of year, month, day-of-month and day-of-week, then there is only one way to resolve a date, but the parsed value for day-of-week will be cross-checked against the resolved date. Calling this method with the arguments YEAR, MONTH_OF_YEAR and DAY_OF_MONTH will ensure that the date is resolved correctly, but without any cross-check for the day-of-week. 

In implementation terms, this method behaves as follows. The result of the
parsing phase can be considered to be a map of field to value. The behavior
of this method is to cause that map to be filtered between phase 1 and 2,
removing all fields other than those specified as arguments to this method.

This instance is immutable and unaffected by this method call.
Params: resolverFields –  the new set of resolver fields, null if no fields
Returns: a formatter based on this formatter with the requested resolver style, not null/**
     * Returns a copy of this formatter with a new set of resolver fields.
     * <p>
     * This returns a formatter with similar state to this formatter but with
     * the resolver fields set. By default, a formatter has no resolver fields.
     * <p>
     * Changing the resolver fields only has an effect during parsing.
     * Parsing a text string occurs in two phases.
     * Phase 1 is a basic text parse according to the fields added to the builder.
     * Phase 2 resolves the parsed field-value pairs into date and/or time objects.
     * The resolver fields are used to filter the field-value pairs between phase 1 and 2.
     * <p>
     * This can be used to select between two or more ways that a date or time might
     * be resolved. For example, if the formatter consists of year, month, day-of-month
     * and day-of-year, then there are two ways to resolve a date.
     * Calling this method with the arguments {@link ChronoField#YEAR YEAR} and
     * {@link ChronoField#DAY_OF_YEAR DAY_OF_YEAR} will ensure that the date is
     * resolved using the year and day-of-year, effectively meaning that the month
     * and day-of-month are ignored during the resolving phase.
     * <p>
     * In a similar manner, this method can be used to ignore secondary fields that
     * would otherwise be cross-checked. For example, if the formatter consists of year,
     * month, day-of-month and day-of-week, then there is only one way to resolve a
     * date, but the parsed value for day-of-week will be cross-checked against the
     * resolved date. Calling this method with the arguments {@link ChronoField#YEAR YEAR},
     * {@link ChronoField#MONTH_OF_YEAR MONTH_OF_YEAR} and
     * {@link ChronoField#DAY_OF_MONTH DAY_OF_MONTH} will ensure that the date is
     * resolved correctly, but without any cross-check for the day-of-week.
     * <p>
     * In implementation terms, this method behaves as follows. The result of the
     * parsing phase can be considered to be a map of field to value. The behavior
     * of this method is to cause that map to be filtered between phase 1 and 2,
     * removing all fields other than those specified as arguments to this method.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param resolverFields  the new set of resolver fields, null if no fields
     * @return a formatter based on this formatter with the requested resolver style, not null
     */
    public DateTimeFormatter withResolverFields(TemporalField... resolverFields) {
        Set<TemporalField> fields = null;
        if (resolverFields != null) {
            // Set.of cannot be used because it is hostile to nulls and duplicate elements
            fields = Collections.unmodifiableSet(new HashSet<>(Arrays.asList(resolverFields)));
        }
        if (Objects.equals(this.resolverFields, fields)) {
            return this;
        }
        return new DateTimeFormatter(printerParser, locale, decimalStyle, resolverStyle, fields, chrono, zone);
    }

    Returns a copy of this formatter with a new set of resolver fields.

This returns a formatter with similar state to this formatter but with
the resolver fields set. By default, a formatter has no resolver fields.

Changing the resolver fields only has an effect during parsing.
Parsing a text string occurs in two phases.
Phase 1 is a basic text parse according to the fields added to the builder.
Phase 2 resolves the parsed field-value pairs into date and/or time objects.
The resolver fields are used to filter the field-value pairs between phase 1 and 2.
 This can be used to select between two or more ways that a date or time might be resolved. For example, if the formatter consists of year, month, day-of-month and day-of-year, then there are two ways to resolve a date. Calling this method with the arguments YEAR and DAY_OF_YEAR will ensure that the date is resolved using the year and day-of-year, effectively meaning that the month and day-of-month are ignored during the resolving phase. 
 In a similar manner, this method can be used to ignore secondary fields that would otherwise be cross-checked. For example, if the formatter consists of year, month, day-of-month and day-of-week, then there is only one way to resolve a date, but the parsed value for day-of-week will be cross-checked against the resolved date. Calling this method with the arguments YEAR, MONTH_OF_YEAR and DAY_OF_MONTH will ensure that the date is resolved correctly, but without any cross-check for the day-of-week. 

In implementation terms, this method behaves as follows. The result of the
parsing phase can be considered to be a map of field to value. The behavior
of this method is to cause that map to be filtered between phase 1 and 2,
removing all fields other than those specified as arguments to this method.

This instance is immutable and unaffected by this method call.
Params: resolverFields –  the new set of resolver fields, null if no fields
Returns: a formatter based on this formatter with the requested resolver style, not null/**
     * Returns a copy of this formatter with a new set of resolver fields.
     * <p>
     * This returns a formatter with similar state to this formatter but with
     * the resolver fields set. By default, a formatter has no resolver fields.
     * <p>
     * Changing the resolver fields only has an effect during parsing.
     * Parsing a text string occurs in two phases.
     * Phase 1 is a basic text parse according to the fields added to the builder.
     * Phase 2 resolves the parsed field-value pairs into date and/or time objects.
     * The resolver fields are used to filter the field-value pairs between phase 1 and 2.
     * <p>
     * This can be used to select between two or more ways that a date or time might
     * be resolved. For example, if the formatter consists of year, month, day-of-month
     * and day-of-year, then there are two ways to resolve a date.
     * Calling this method with the arguments {@link ChronoField#YEAR YEAR} and
     * {@link ChronoField#DAY_OF_YEAR DAY_OF_YEAR} will ensure that the date is
     * resolved using the year and day-of-year, effectively meaning that the month
     * and day-of-month are ignored during the resolving phase.
     * <p>
     * In a similar manner, this method can be used to ignore secondary fields that
     * would otherwise be cross-checked. For example, if the formatter consists of year,
     * month, day-of-month and day-of-week, then there is only one way to resolve a
     * date, but the parsed value for day-of-week will be cross-checked against the
     * resolved date. Calling this method with the arguments {@link ChronoField#YEAR YEAR},
     * {@link ChronoField#MONTH_OF_YEAR MONTH_OF_YEAR} and
     * {@link ChronoField#DAY_OF_MONTH DAY_OF_MONTH} will ensure that the date is
     * resolved correctly, but without any cross-check for the day-of-week.
     * <p>
     * In implementation terms, this method behaves as follows. The result of the
     * parsing phase can be considered to be a map of field to value. The behavior
     * of this method is to cause that map to be filtered between phase 1 and 2,
     * removing all fields other than those specified as arguments to this method.
     * <p>
     * This instance is immutable and unaffected by this method call.
     *
     * @param resolverFields  the new set of resolver fields, null if no fields
     * @return a formatter based on this formatter with the requested resolver style, not null
     */
    public DateTimeFormatter withResolverFields(Set<TemporalField> resolverFields) {
        if (Objects.equals(this.resolverFields, resolverFields)) {
            return this;
        }
        if (resolverFields != null) {
            resolverFields = Collections.unmodifiableSet(new HashSet<>(resolverFields));
        }
        return new DateTimeFormatter(printerParser, locale, decimalStyle, resolverStyle, resolverFields, chrono, zone);
    }

    //-----------------------------------------------------------------------
    Formats a date-time object using this formatter.

This formats the date-time to a String using the rules of the formatter.
Params: temporal –  the temporal object to format, not null
Throws: DateTimeException – if an error occurs during formatting
Returns: the formatted string, not null/**
     * Formats a date-time object using this formatter.
     * <p>
     * This formats the date-time to a String using the rules of the formatter.
     *
     * @param temporal  the temporal object to format, not null
     * @return the formatted string, not null
     * @throws DateTimeException if an error occurs during formatting
     */
    public String format(TemporalAccessor temporal) {
        StringBuilder buf = new StringBuilder(32);
        formatTo(temporal, buf);
        return buf.toString();
    }

    //-----------------------------------------------------------------------
    Formats a date-time object to an Appendable using this formatter.  This outputs the formatted date-time to the specified destination. Appendable is a general purpose interface that is implemented by all key character output classes including StringBuffer, StringBuilder, PrintStream and Writer. 
 Although Appendable methods throw an IOException, this method does not. Instead, any IOException is wrapped in a runtime exception. 
Params: temporal –  the temporal object to format, not null
appendable –  the appendable to format to, not null
Throws: DateTimeException – if an error occurs during formatting/**
     * Formats a date-time object to an {@code Appendable} using this formatter.
     * <p>
     * This outputs the formatted date-time to the specified destination.
     * {@link Appendable} is a general purpose interface that is implemented by all
     * key character output classes including {@code StringBuffer}, {@code StringBuilder},
     * {@code PrintStream} and {@code Writer}.
     * <p>
     * Although {@code Appendable} methods throw an {@code IOException}, this method does not.
     * Instead, any {@code IOException} is wrapped in a runtime exception.
     *
     * @param temporal  the temporal object to format, not null
     * @param appendable  the appendable to format to, not null
     * @throws DateTimeException if an error occurs during formatting
     */
    public void formatTo(TemporalAccessor temporal, Appendable appendable) {
        Objects.requireNonNull(temporal, "temporal");
        Objects.requireNonNull(appendable, "appendable");
        try {
            DateTimePrintContext context = new DateTimePrintContext(temporal, this);
            if (appendable instanceof StringBuilder) {
                printerParser.format(context, (StringBuilder) appendable);
            } else {
                // buffer output to avoid writing to appendable in case of error
                StringBuilder buf = new StringBuilder(32);
                printerParser.format(context, buf);
                appendable.append(buf);
            }
        } catch (IOException ex) {
            throw new DateTimeException(ex.getMessage(), ex);
        }
    }

    //-----------------------------------------------------------------------
    Fully parses the text producing a temporal object.
 This parses the entire text producing a temporal object. It is typically more useful to use parse(CharSequence, TemporalQuery<Object>). The result of this method is TemporalAccessor which has been resolved, applying basic validation checks to help ensure a valid date-time. 

If the parse completes without reading the entire length of the text,
or a problem occurs during parsing or merging, then an exception is thrown.
Params: text –  the text to parse, not null
Throws: DateTimeParseException – if unable to parse the requested result
Returns: the parsed temporal object, not null/**
     * Fully parses the text producing a temporal object.
     * <p>
     * This parses the entire text producing a temporal object.
     * It is typically more useful to use {@link #parse(CharSequence, TemporalQuery)}.
     * The result of this method is {@code TemporalAccessor} which has been resolved,
     * applying basic validation checks to help ensure a valid date-time.
     * <p>
     * If the parse completes without reading the entire length of the text,
     * or a problem occurs during parsing or merging, then an exception is thrown.
     *
     * @param text  the text to parse, not null
     * @return the parsed temporal object, not null
     * @throws DateTimeParseException if unable to parse the requested result
     */
    public TemporalAccessor parse(CharSequence text) {
        Objects.requireNonNull(text, "text");
        try {
            return parseResolved0(text, null);
        } catch (DateTimeParseException ex) {
            throw ex;
        } catch (RuntimeException ex) {
            throw createError(text, ex);
        }
    }

    Parses the text using this formatter, providing control over the text position.
 This parses the text without requiring the parse to start from the beginning of the string or finish at the end. The result of this method is TemporalAccessor which has been resolved, applying basic validation checks to help ensure a valid date-time. 
 The text will be parsed from the specified start ParsePosition. The entire length of the text does not have to be parsed, the ParsePosition will be updated with the index at the end of parsing. 
 The operation of this method is slightly different to similar methods using ParsePosition on java.text.Format. That class will return errors using the error index on the ParsePosition. By contrast, this method will throw a DateTimeParseException if an error occurs, with the exception containing the error index. This change in behavior is necessary due to the increased complexity of parsing and resolving dates/times in this API. 

If the formatter parses the same field more than once with different values,
the result will be an error.
Params: text –  the text to parse, not null
position –  the position to parse from, updated with length parsed
 and the index of any error, not null
Throws: DateTimeParseException – if unable to parse the requested result
IndexOutOfBoundsException – if the position is invalid
Returns: the parsed temporal object, not null/**
     * Parses the text using this formatter, providing control over the text position.
     * <p>
     * This parses the text without requiring the parse to start from the beginning
     * of the string or finish at the end.
     * The result of this method is {@code TemporalAccessor} which has been resolved,
     * applying basic validation checks to help ensure a valid date-time.
     * <p>
     * The text will be parsed from the specified start {@code ParsePosition}.
     * The entire length of the text does not have to be parsed, the {@code ParsePosition}
     * will be updated with the index at the end of parsing.
     * <p>
     * The operation of this method is slightly different to similar methods using
     * {@code ParsePosition} on {@code java.text.Format}. That class will return
     * errors using the error index on the {@code ParsePosition}. By contrast, this
     * method will throw a {@link DateTimeParseException} if an error occurs, with
     * the exception containing the error index.
     * This change in behavior is necessary due to the increased complexity of
     * parsing and resolving dates/times in this API.
     * <p>
     * If the formatter parses the same field more than once with different values,
     * the result will be an error.
     *
     * @param text  the text to parse, not null
     * @param position  the position to parse from, updated with length parsed
     *  and the index of any error, not null
     * @return the parsed temporal object, not null
     * @throws DateTimeParseException if unable to parse the requested result
     * @throws IndexOutOfBoundsException if the position is invalid
     */
    public TemporalAccessor parse(CharSequence text, ParsePosition position) {
        Objects.requireNonNull(text, "text");
        Objects.requireNonNull(position, "position");
        try {
            return parseResolved0(text, position);
        } catch (DateTimeParseException | IndexOutOfBoundsException ex) {
            throw ex;
        } catch (RuntimeException ex) {
            throw createError(text, ex);
        }
    }

    //-----------------------------------------------------------------------
    Fully parses the text producing an object of the specified type.
 Most applications should use this method for parsing. It parses the entire text to produce the required date-time. The query is typically a method reference to a from(TemporalAccessor) method. For example: 
 LocalDateTime dt = parser.parse(str, LocalDateTime::from);

If the parse completes without reading the entire length of the text,
or a problem occurs during parsing or merging, then an exception is thrown.
Params: text –  the text to parse, not null
query –  the query defining the type to parse to, not null
Type parameters: <T> – the type of the parsed date-time
Throws: DateTimeParseException – if unable to parse the requested result
Returns: the parsed date-time, not null/**
     * Fully parses the text producing an object of the specified type.
     * <p>
     * Most applications should use this method for parsing.
     * It parses the entire text to produce the required date-time.
     * The query is typically a method reference to a {@code from(TemporalAccessor)} method.
     * For example:
     * <pre>
     *  LocalDateTime dt = parser.parse(str, LocalDateTime::from);
     * </pre>
     * If the parse completes without reading the entire length of the text,
     * or a problem occurs during parsing or merging, then an exception is thrown.
     *
     * @param <T> the type of the parsed date-time
     * @param text  the text to parse, not null
     * @param query  the query defining the type to parse to, not null
     * @return the parsed date-time, not null
     * @throws DateTimeParseException if unable to parse the requested result
     */
    public <T> T parse(CharSequence text, TemporalQuery<T> query) {
        Objects.requireNonNull(text, "text");
        Objects.requireNonNull(query, "query");
        try {
            return parseResolved0(text, null).query(query);
        } catch (DateTimeParseException ex) {
            throw ex;
        } catch (RuntimeException ex) {
            throw createError(text, ex);
        }
    }

    Fully parses the text producing an object of one of the specified types.
 This parse method is convenient for use when the parser can handle optional elements. For example, a pattern of 'uuuu-MM-dd HH.mm[ VV]' can be fully parsed to a ZonedDateTime, or partially parsed to a LocalDateTime. The queries must be specified in order, starting from the best matching full-parse option and ending with the worst matching minimal parse option. The query is typically a method reference to a from(TemporalAccessor) method. 
 The result is associated with the first type that successfully parses. Normally, applications will use instanceof to check the result. For example: 
 TemporalAccessor dt = parser.parseBest(str, ZonedDateTime::from, LocalDateTime::from);
 if (dt instanceof ZonedDateTime) {
  ...
 } else {
  ...
 }

If the parse completes without reading the entire length of the text,
or a problem occurs during parsing or merging, then an exception is thrown.
Params: text –  the text to parse, not null
queries –  the queries defining the types to attempt to parse to, must implement TemporalAccessor, not null
Throws: IllegalArgumentException – if less than 2 types are specified
DateTimeParseException – if unable to parse the requested result
Returns: the parsed date-time, not null/**
     * Fully parses the text producing an object of one of the specified types.
     * <p>
     * This parse method is convenient for use when the parser can handle optional elements.
     * For example, a pattern of 'uuuu-MM-dd HH.mm[ VV]' can be fully parsed to a {@code ZonedDateTime},
     * or partially parsed to a {@code LocalDateTime}.
     * The queries must be specified in order, starting from the best matching full-parse option
     * and ending with the worst matching minimal parse option.
     * The query is typically a method reference to a {@code from(TemporalAccessor)} method.
     * <p>
     * The result is associated with the first type that successfully parses.
     * Normally, applications will use {@code instanceof} to check the result.
     * For example:
     * <pre>
     *  TemporalAccessor dt = parser.parseBest(str, ZonedDateTime::from, LocalDateTime::from);
     *  if (dt instanceof ZonedDateTime) {
     *   ...
     *  } else {
     *   ...
     *  }
     * </pre>
     * If the parse completes without reading the entire length of the text,
     * or a problem occurs during parsing or merging, then an exception is thrown.
     *
     * @param text  the text to parse, not null
     * @param queries  the queries defining the types to attempt to parse to,
     *  must implement {@code TemporalAccessor}, not null
     * @return the parsed date-time, not null
     * @throws IllegalArgumentException if less than 2 types are specified
     * @throws DateTimeParseException if unable to parse the requested result
     */
    public TemporalAccessor parseBest(CharSequence text, TemporalQuery<?>... queries) {
        Objects.requireNonNull(text, "text");
        Objects.requireNonNull(queries, "queries");
        if (queries.length < 2) {
            throw new IllegalArgumentException("At least two queries must be specified");
        }
        try {
            TemporalAccessor resolved = parseResolved0(text, null);
            for (TemporalQuery<?> query : queries) {
                try {
                    return (TemporalAccessor) resolved.query(query);
                } catch (RuntimeException ex) {
                    // continue
                }
            }
            throw new DateTimeException("Unable to convert parsed text using any of the specified queries");
        } catch (DateTimeParseException ex) {
            throw ex;
        } catch (RuntimeException ex) {
            throw createError(text, ex);
        }
    }

    private DateTimeParseException createError(CharSequence text, RuntimeException ex) {
        String abbr;
        if (text.length() > 64) {
            abbr = text.subSequence(0, 64).toString() + "...";
        } else {
            abbr = text.toString();
        }
        return new DateTimeParseException("Text '" + abbr + "' could not be parsed: " + ex.getMessage(), text, 0, ex);
    }

    //-----------------------------------------------------------------------
    Parses and resolves the specified text.
 This parses to a TemporalAccessor ensuring that the text is fully parsed. 
Params: text –  the text to parse, not null
position –  the position to parse from, updated with length parsed
 and the index of any error, null if parsing whole string
Throws: DateTimeParseException – if the parse fails
DateTimeException – if an error occurs while resolving the date or time
IndexOutOfBoundsException – if the position is invalid
Returns: the resolved result of the parse, not null/**
     * Parses and resolves the specified text.
     * <p>
     * This parses to a {@code TemporalAccessor} ensuring that the text is fully parsed.
     *
     * @param text  the text to parse, not null
     * @param position  the position to parse from, updated with length parsed
     *  and the index of any error, null if parsing whole string
     * @return the resolved result of the parse, not null
     * @throws DateTimeParseException if the parse fails
     * @throws DateTimeException if an error occurs while resolving the date or time
     * @throws IndexOutOfBoundsException if the position is invalid
     */
    private TemporalAccessor parseResolved0(final CharSequence text, final ParsePosition position) {
        ParsePosition pos = (position != null ? position : new ParsePosition(0));
        DateTimeParseContext context = parseUnresolved0(text, pos);
        if (context == null || pos.getErrorIndex() >= 0 || (position == null && pos.getIndex() < text.length())) {
            String abbr;
            if (text.length() > 64) {
                abbr = text.subSequence(0, 64).toString() + "...";
            } else {
                abbr = text.toString();
            }
            if (pos.getErrorIndex() >= 0) {
                throw new DateTimeParseException("Text '" + abbr + "' could not be parsed at index " +
                        pos.getErrorIndex(), text, pos.getErrorIndex());
            } else {
                throw new DateTimeParseException("Text '" + abbr + "' could not be parsed, unparsed text found at index " +
                        pos.getIndex(), text, pos.getIndex());
            }
        }
        return context.toResolved(resolverStyle, resolverFields);
    }

    Parses the text using this formatter, without resolving the result, intended
for advanced use cases.
 Parsing is implemented as a two-phase operation. First, the text is parsed using the layout defined by the formatter, producing a Map of field to value, a ZoneId and a Chronology. Second, the parsed data is resolved, by validating, combining and
simplifying the various fields into more useful ones.
This method performs the parsing stage but not the resolving stage.
 The result of this method is TemporalAccessor which represents the data as seen in the input. Values are not validated, thus parsing a date string of '2012-00-65' would result in a temporal with three fields - year of '2012', month of '0' and day-of-month of '65'. 
 The text will be parsed from the specified start ParsePosition. The entire length of the text does not have to be parsed, the ParsePosition will be updated with the index at the end of parsing. 
 Errors are returned using the error index field of the ParsePosition instead of DateTimeParseException. The returned error index will be set to an index indicative of the error. Callers must check for errors before using the result. 

If the formatter parses the same field more than once with different values,
the result will be an error.
 This method is intended for advanced use cases that need access to the internal state during parsing. Typical application code should use parse(CharSequence, TemporalQuery<Object>) or the parse method on the target type. 
Params: text –  the text to parse, not null
position –  the position to parse from, updated with length parsed
 and the index of any error, not null
Throws: DateTimeException – if some problem occurs during parsing
IndexOutOfBoundsException – if the position is invalid
Returns: the parsed text, null if the parse results in an error/**
     * Parses the text using this formatter, without resolving the result, intended
     * for advanced use cases.
     * <p>
     * Parsing is implemented as a two-phase operation.
     * First, the text is parsed using the layout defined by the formatter, producing
     * a {@code Map} of field to value, a {@code ZoneId} and a {@code Chronology}.
     * Second, the parsed data is <em>resolved</em>, by validating, combining and
     * simplifying the various fields into more useful ones.
     * This method performs the parsing stage but not the resolving stage.
     * <p>
     * The result of this method is {@code TemporalAccessor} which represents the
     * data as seen in the input. Values are not validated, thus parsing a date string
     * of '2012-00-65' would result in a temporal with three fields - year of '2012',
     * month of '0' and day-of-month of '65'.
     * <p>
     * The text will be parsed from the specified start {@code ParsePosition}.
     * The entire length of the text does not have to be parsed, the {@code ParsePosition}
     * will be updated with the index at the end of parsing.
     * <p>
     * Errors are returned using the error index field of the {@code ParsePosition}
     * instead of {@code DateTimeParseException}.
     * The returned error index will be set to an index indicative of the error.
     * Callers must check for errors before using the result.
     * <p>
     * If the formatter parses the same field more than once with different values,
     * the result will be an error.
     * <p>
     * This method is intended for advanced use cases that need access to the
     * internal state during parsing. Typical application code should use
     * {@link #parse(CharSequence, TemporalQuery)} or the parse method on the target type.
     *
     * @param text  the text to parse, not null
     * @param position  the position to parse from, updated with length parsed
     *  and the index of any error, not null
     * @return the parsed text, null if the parse results in an error
     * @throws DateTimeException if some problem occurs during parsing
     * @throws IndexOutOfBoundsException if the position is invalid
     */
    public TemporalAccessor parseUnresolved(CharSequence text, ParsePosition position) {
        DateTimeParseContext context = parseUnresolved0(text, position);
        if (context == null) {
            return null;
        }
        return context.toUnresolved();
    }

    private DateTimeParseContext parseUnresolved0(CharSequence text, ParsePosition position) {
        Objects.requireNonNull(text, "text");
        Objects.requireNonNull(position, "position");
        DateTimeParseContext context = new DateTimeParseContext(this);
        int pos = position.getIndex();
        pos = printerParser.parse(context, text, pos);
        if (pos < 0) {
            position.setErrorIndex(~pos);  // index not updated from input
            return null;
        }
        position.setIndex(pos);  // errorIndex not updated from input
        return context;
    }

    //-----------------------------------------------------------------------
    Returns the formatter as a composite printer parser.
Params: optional –  whether the printer/parser should be optional
Returns: the printer/parser, not null/**
     * Returns the formatter as a composite printer parser.
     *
     * @param optional  whether the printer/parser should be optional
     * @return the printer/parser, not null
     */
    CompositePrinterParser toPrinterParser(boolean optional) {
        return printerParser.withOptional(optional);
    }

    Returns this formatter as a java.text.Format instance.  The returned Format instance will format any TemporalAccessor and parses to a resolved TemporalAccessor. 
 Exceptions will follow the definitions of Format, see those methods for details about IllegalArgumentException during formatting and ParseException or null during parsing. The format does not support attributing of the returned format string. 
Returns: this formatter as a classic format instance, not null/**
     * Returns this formatter as a {@code java.text.Format} instance.
     * <p>
     * The returned {@link Format} instance will format any {@link TemporalAccessor}
     * and parses to a resolved {@link TemporalAccessor}.
     * <p>
     * Exceptions will follow the definitions of {@code Format}, see those methods
     * for details about {@code IllegalArgumentException} during formatting and
     * {@code ParseException} or null during parsing.
     * The format does not support attributing of the returned format string.
     *
     * @return this formatter as a classic format instance, not null
     */
    public Format toFormat() {
        return new ClassicFormat(this, null);
    }

    Returns this formatter as a java.text.Format instance that will parse using the specified query.  The returned Format instance will format any TemporalAccessor and parses to the type specified. The type must be one that is supported by parse. 
 Exceptions will follow the definitions of Format, see those methods for details about IllegalArgumentException during formatting and ParseException or null during parsing. The format does not support attributing of the returned format string. 
Params: parseQuery –  the query defining the type to parse to, not null
Returns: this formatter as a classic format instance, not null/**
     * Returns this formatter as a {@code java.text.Format} instance that will
     * parse using the specified query.
     * <p>
     * The returned {@link Format} instance will format any {@link TemporalAccessor}
     * and parses to the type specified.
     * The type must be one that is supported by {@link #parse}.
     * <p>
     * Exceptions will follow the definitions of {@code Format}, see those methods
     * for details about {@code IllegalArgumentException} during formatting and
     * {@code ParseException} or null during parsing.
     * The format does not support attributing of the returned format string.
     *
     * @param parseQuery  the query defining the type to parse to, not null
     * @return this formatter as a classic format instance, not null
     */
    public Format toFormat(TemporalQuery<?> parseQuery) {
        Objects.requireNonNull(parseQuery, "parseQuery");
        return new ClassicFormat(this, parseQuery);
    }

    //-----------------------------------------------------------------------
    Returns a description of the underlying formatters.
Returns: a description of this formatter, not null/**
     * Returns a description of the underlying formatters.
     *
     * @return a description of this formatter, not null
     */
    @Override
    public String toString() {
        String pattern = printerParser.toString();
        pattern = pattern.startsWith("[") ? pattern : pattern.substring(1, pattern.length() - 1);
        return pattern;
        // TODO: Fix tests to not depend on toString()
//        return "DateTimeFormatter[" + locale +
//                (chrono != null ? "," + chrono : "") +
//                (zone != null ? "," + zone : "") +
//                pattern + "]";
    }

    //-----------------------------------------------------------------------
    Implements the classic Java Format API.
@serial exclude/**
     * Implements the classic Java Format API.
     * @serial exclude
     */
    @SuppressWarnings("serial")  // not actually serializable
    static class ClassicFormat extends Format {
        The formatter. /** The formatter. */
        private final DateTimeFormatter formatter;
        The type to be parsed. /** The type to be parsed. */
        private final TemporalQuery<?> parseType;
        Constructor. /** Constructor. */
        public ClassicFormat(DateTimeFormatter formatter, TemporalQuery<?> parseType) {
            this.formatter = formatter;
            this.parseType = parseType;
        }

        @Override
        public StringBuffer format(Object obj, StringBuffer toAppendTo, FieldPosition pos) {
            Objects.requireNonNull(obj, "obj");
            Objects.requireNonNull(toAppendTo, "toAppendTo");
            Objects.requireNonNull(pos, "pos");
            if (obj instanceof TemporalAccessor == false) {
                throw new IllegalArgumentException("Format target must implement TemporalAccessor");
            }
            pos.setBeginIndex(0);
            pos.setEndIndex(0);
            try {
                formatter.formatTo((TemporalAccessor) obj, toAppendTo);
            } catch (RuntimeException ex) {
                throw new IllegalArgumentException(ex.getMessage(), ex);
            }
            return toAppendTo;
        }
        @Override
        public Object parseObject(String text) throws ParseException {
            Objects.requireNonNull(text, "text");
            try {
                if (parseType == null) {
                    return formatter.parseResolved0(text, null);
                }
                return formatter.parse(text, parseType);
            } catch (DateTimeParseException ex) {
                throw new ParseException(ex.getMessage(), ex.getErrorIndex());
            } catch (RuntimeException ex) {
                throw (ParseException) new ParseException(ex.getMessage(), 0).initCause(ex);
            }
        }
        @Override
        public Object parseObject(String text, ParsePosition pos) {
            Objects.requireNonNull(text, "text");
            DateTimeParseContext context;
            try {
                context = formatter.parseUnresolved0(text, pos);
            } catch (IndexOutOfBoundsException ex) {
                if (pos.getErrorIndex() < 0) {
                    pos.setErrorIndex(0);
                }
                return null;
            }
            if (context == null) {
                if (pos.getErrorIndex() < 0) {
                    pos.setErrorIndex(0);
                }
                return null;
            }
            try {
                TemporalAccessor resolved = context.toResolved(formatter.resolverStyle, formatter.resolverFields);
                if (parseType == null) {
                    return resolved;
                }
                return resolved.query(parseType);
            } catch (RuntimeException ex) {
                pos.setErrorIndex(0);
                return null;
            }
        }
    }

}
Formatter	Description	Example
`ofLocalizedDate(dateStyle)`	Formatter with date style from the locale	'2011-12-03'
`ofLocalizedTime(timeStyle)`	Formatter with time style from the locale	'10:15:30'
`ofLocalizedDateTime(dateTimeStyle)`	Formatter with a style for date and time from the locale	'3 Jun 2008 11:05:30'
`ofLocalizedDateTime(dateStyle,timeStyle)`	Formatter with date and time styles from the locale	'3 Jun 2008 11:05'
`BASIC_ISO_DATE`	Basic ISO date	'20111203'
`ISO_LOCAL_DATE`	ISO Local Date	'2011-12-03'
`ISO_OFFSET_DATE`	ISO Date with offset	'2011-12-03+01:00'
`ISO_DATE`	ISO Date with or without offset	'2011-12-03+01:00'; '2011-12-03'
`ISO_LOCAL_TIME`	Time without offset	'10:15:30'
`ISO_OFFSET_TIME`	Time with offset	'10:15:30+01:00'
`ISO_TIME`	Time with or without offset	'10:15:30+01:00'; '10:15:30'
`ISO_LOCAL_DATE_TIME`	ISO Local Date and Time	'2011-12-03T10:15:30'
`ISO_OFFSET_DATE_TIME`	Date Time with Offset	'2011-12-03T10:15:30+01:00'
`ISO_ZONED_DATE_TIME`	Zoned Date Time	'2011-12-03T10:15:30+01:00[Europe/Paris]'
`ISO_DATE_TIME`	Date and time with ZoneId	'2011-12-03T10:15:30+01:00[Europe/Paris]'
`ISO_ORDINAL_DATE`	Year and day of year	'2012-337'
`ISO_WEEK_DATE`	Year and Week	'2012-W48-6'
`ISO_INSTANT`	Date and Time of an Instant	'2011-12-03T10:15:30Z'
`RFC_1123_DATE_TIME`	RFC 1123 / RFC 822	'Tue, 3 Jun 2008 11:05:30 GMT'
Symbol	Meaning	Presentation	Examples
G	era	text	AD; Anno Domini; A
u	year	year	2004; 04
y	year-of-era	year	2004; 04
D	day-of-year	number	189
M/L	month-of-year	number/text	7; 07; Jul; July; J
d	day-of-month	number	10
g	modified-julian-day	number	2451334
Q/q	quarter-of-year	number/text	3; 03; Q3; 3rd quarter
Y	week-based-year	year	1996; 96
w	week-of-week-based-year	number	27
W	week-of-month	number	4
E	day-of-week	text	Tue; Tuesday; T
e/c	localized day-of-week	number/text	2; 02; Tue; Tuesday; T
F	day-of-week-in-month	number	3
a	am-pm-of-day	text	PM
h	clock-hour-of-am-pm (1-12)	number	12
K	hour-of-am-pm (0-11)	number	0
k	clock-hour-of-day (1-24)	number	24
H	hour-of-day (0-23)	number	0
m	minute-of-hour	number	30
s	second-of-minute	number	55
S	fraction-of-second	fraction	978
A	milli-of-day	number	1234
n	nano-of-second	number	987654321
N	nano-of-day	number	1234000000
V	time-zone ID	zone-id	America/Los_Angeles; Z; -08:30
v	generic time-zone name	zone-name	Pacific Time; PT
z	time-zone name	zone-name	Pacific Standard Time; PST
O	localized zone-offset	offset-O	GMT+8; GMT+08:00; UTC-08:00
X	zone-offset 'Z' for zero	offset-X	Z; -08; -0830; -08:30; -083015; -08:30:15
x	zone-offset	offset-x	+0000; -08; -0830; -08:30; -083015; -08:30:15
Z	zone-offset	offset-Z	+0000; -0800; -08:00
p	pad next	pad modifier	1
'	escape for text	delimiter
''	single quote	literal	'
[	optional section start
]	optional section end
#	reserved for future use
{	reserved for future use
}	reserved for future use
Implementation Requirements:	This class is immutable and thread-safe.
Since:	1.8
Params:	pattern – the pattern to use, not null
Throws:	IllegalArgumentException – if the pattern is invalid
See Also:	DateTimeFormatterBuilder.appendPattern(String)
Returns:	the formatter based on the pattern, not null
Params:	pattern – the pattern to use, not null locale – the locale to use, not null
Throws:	IllegalArgumentException – if the pattern is invalid
See Also:	DateTimeFormatterBuilder.appendPattern(String)
Returns:	the formatter based on the pattern, not null
Params:	dateStyle – the formatter style to obtain, not null
Returns:	the date formatter, not null
Params:	timeStyle – the formatter style to obtain, not null
Returns:	the time formatter, not null
Params:	dateTimeStyle – the formatter style to obtain, not null
Returns:	the date-time formatter, not null
Params:	dateStyle – the date formatter style to obtain, not null timeStyle – the time formatter style to obtain, not null
Returns:	the date, time or date-time formatter, not null
Params:	locale – the new locale, not null
See Also:	localizedBy(Locale)
Returns:	a formatter based on this formatter with the requested locale, not null
Params:	locale – the locale, not null
See Also:	withLocale(Locale)
Returns:	a formatter based on this formatter with localized values of the calendar, decimal style and/or timezone, that supercede values in this formatter.
Since:	10
Params:	decimalStyle – the new DecimalStyle, not null
Returns:	a formatter based on this formatter with the requested DecimalStyle, not null
Params:	chrono – the new chronology, null if no override
Returns:	a formatter based on this formatter with the requested override chronology, not null
Params:	zone – the new override zone, null if no override
Returns:	a formatter based on this formatter with the requested override zone, not null
Params:	resolverStyle – the new resolver style, not null
Returns:	a formatter based on this formatter with the requested resolver style, not null
Params:	resolverFields – the new set of resolver fields, null if no fields
Returns:	a formatter based on this formatter with the requested resolver style, not null
Params:	temporal – the temporal object to format, not null
Throws:	DateTimeException – if an error occurs during formatting
Returns:	the formatted string, not null
Params:	text – the text to parse, not null
Throws:	DateTimeParseException – if unable to parse the requested result
Returns:	the parsed temporal object, not null
Params:	text – the text to parse, not null position – the position to parse from, updated with length parsed and the index of any error, not null
Throws:	DateTimeParseException – if unable to parse the requested result IndexOutOfBoundsException – if the position is invalid
Returns:	the parsed temporal object, not null
Params:	text – the text to parse, not null query – the query defining the type to parse to, not null
Type parameters:	<T> – the type of the parsed date-time
Throws:	DateTimeParseException – if unable to parse the requested result
Returns:	the parsed date-time, not null
/

java/ 11/ java.base/java/time/format/DateTimeFormatter.java

Predefined Formatters

Patterns for Formatting and Parsing

Resolving
