DateTimeFormatter

BASIC_ISO_DATE

public static final DateTimeFormatter BASIC_ISO_DATE

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 DateTimeFormatter.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.

ISO_DATE

public static final DateTimeFormatter ISO_DATE

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 DateTimeFormatter.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.

ISO_DATE_TIME

public static final DateTimeFormatter ISO_DATE_TIME

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 DateTimeFormatter.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.

ISO_INSTANT

public static final DateTimeFormatter ISO_INSTANT

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 instant will always be suffixed by 'Z' to indicate UTC. The second-of-minute is always output. The nano-of-second outputs zero, three, six or nine digits as necessary. When parsing, the behaviour of DateTimeFormatterBuilder.appendOffsetId() will be used to parse the offset, converting the instant to UTC as necessary. The 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.

ISO_LOCAL_DATE

public static final DateTimeFormatter ISO_LOCAL_DATE

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.

ISO_LOCAL_DATE_TIME

public static final DateTimeFormatter ISO_LOCAL_DATE_TIME

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.

ISO_LOCAL_TIME

public static final DateTimeFormatter ISO_LOCAL_TIME

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.

ISO_OFFSET_DATE

public static final DateTimeFormatter ISO_OFFSET_DATE

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.

ISO_OFFSET_DATE_TIME

public static final DateTimeFormatter ISO_OFFSET_DATE_TIME

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.

ISO_OFFSET_TIME

public static final DateTimeFormatter ISO_OFFSET_TIME

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.

ISO_ORDINAL_DATE

public static final DateTimeFormatter ISO_ORDINAL_DATE

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 DateTimeFormatter.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.

ISO_TIME

public static final DateTimeFormatter ISO_TIME

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 DateTimeFormatter.parseBest.

The returned formatter has no override chronology or zone. It uses the STRICT resolver style.

ISO_WEEK_DATE

public static final DateTimeFormatter ISO_WEEK_DATE

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 DateTimeFormatter.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.

ISO_ZONED_DATE_TIME

public static final DateTimeFormatter ISO_ZONED_DATE_TIME

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.

RFC_1123_DATE_TIME

public static final DateTimeFormatter RFC_1123_DATE_TIME

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.

format

public String format (TemporalAccessor temporal)

Formats a date-time object using this formatter.

This formats the date-time to a String using the rules of the formatter.

formatTo

public void formatTo (TemporalAccessor temporal, 
                Appendable appendable)

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.

getChronology

public Chronology getChronology ()

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(java.time.chrono.Chronology) for more details on overriding.

getDecimalStyle

public DecimalStyle getDecimalStyle ()

Gets the DecimalStyle to be used during formatting.

getLocale

public Locale getLocale ()

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.

getResolverFields

public Set<TemporalField> getResolverFields ()

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(java.util.Set) for more details.

getResolverStyle

public ResolverStyle getResolverStyle ()

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(java.time.format.ResolverStyle) for more details.

getZone

public ZoneId getZone ()

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(java.time.ZoneId) for more details on overriding.

localizedBy

public DateTimeFormatter localizedBy (Locale locale)

Returns a copy of this formatter with localized values of the locale, calendar, decimal style and/or timezone, that superseded 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) and/or "tz" (timezone) Unicode extensions, the chronology, numbering system and/or the zone are overridden.

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.

ofLocalizedDate

public static DateTimeFormatter ofLocalizedDate (FormatStyle dateStyle)

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.

ofLocalizedDateTime

public static DateTimeFormatter ofLocalizedDateTime (FormatStyle dateStyle, 
                FormatStyle timeStyle)

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 DateTimeFormatter.withZone.

ofLocalizedDateTime

public static DateTimeFormatter ofLocalizedDateTime (FormatStyle dateTimeStyle)

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 DateTimeFormatter.withZone.

ofLocalizedTime

public static DateTimeFormatter ofLocalizedTime (FormatStyle timeStyle)

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 DateTimeFormatter.withZone.

ofPattern

public static DateTimeFormatter ofPattern (String pattern)

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 DateTimeFormatter.withLocale(Locale) on the returned formatter. Alternatively use the ofPattern(java.lang.String, java.util.Locale) variant of this method.

The returned formatter has no override chronology or zone. It uses SMART resolver style.

ofPattern

public static DateTimeFormatter ofPattern (String pattern, 
                Locale locale)

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 DateTimeFormatter.withLocale(Locale) on the returned formatter.

The returned formatter has no override chronology or zone. It uses SMART resolver style.

parse

public T parse (CharSequence text, 
                TemporalQuery<T> query)

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);
 

parse

public TemporalAccessor parse (CharSequence text)

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(java.lang.CharSequence, java.time.temporal.TemporalQuery). 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.

parse

public TemporalAccessor parse (CharSequence text, 
                ParsePosition position)

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.

parseBest

public TemporalAccessor parseBest (CharSequence text, 
                TemporalQuery...<?> queries)

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 {
   ...
  }
 

parseUnresolved

public TemporalAccessor parseUnresolved (CharSequence text, 
                ParsePosition position)

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(java.lang.CharSequence, java.time.temporal.TemporalQuery) or the parse method on the target type.

parsedExcessDays

public static TemporalQuery<Period> parsedExcessDays ()

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)
 

  TemporalAccessor parsed = formatter.parse(str);
  LocalTime time = parsed.query(LocalTime::from);
  Period extraDays = parsed.query(DateTimeFormatter.parsedExcessDays());
 

parsedLeapSecond

public static TemporalQuery<Boolean> parsedLeapSecond ()

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
  }
 

toFormat

public Format toFormat (TemporalQuery<?> parseQuery)

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(CharSequence).

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.

toFormat

public Format toFormat ()

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.

toString

public String toString ()

Returns a description of the underlying formatters.

withChronology

public DateTimeFormatter withChronology (Chronology 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.

withDecimalStyle

public DateTimeFormatter withDecimalStyle (DecimalStyle decimalStyle)

Returns a copy of this formatter with a new DecimalStyle.

This instance is immutable and unaffected by this method call.

withLocale

public DateTimeFormatter withLocale (Locale 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.

This instance is immutable and unaffected by this method call.

withResolverFields

public DateTimeFormatter withResolverFields (Set<TemporalField> 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.

withResolverFields

public DateTimeFormatter withResolverFields (TemporalField... 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.

withResolverStyle

public DateTimeFormatter withResolverStyle (ResolverStyle 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.

withZone

public DateTimeFormatter withZone (ZoneId 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.