Package org.threeten.bp.format

Class DateTimeFormatterBuilder

  • public final class DateTimeFormatterBuilder
extends Object
    Builder to create date-time formatters.

    This allows a DateTimeFormatter to be created. All date-time formatters are created ultimately using this builder.

    The basic elements of date-time can all be added:

    • Value - a numeric value
    • Fraction - a fractional value including the decimal place. Always use this when outputting fractions to ensure that the fraction is parsed correctly
    • Text - the textual equivalent for the value
    • OffsetId/Offset - the zone offset
    • ZoneId - the time-zone id
    • ZoneText - the name of the time-zone
    • Literal - a text literal
    • Nested and Optional - formats can be nested or made optional
    • Other - the printer and parser interfaces can be used to add user supplied formatting

    In addition, any of the elements may be decorated by padding, either with spaces or any other character.

    Finally, a shorthand pattern, mostly compatible with java.text.SimpleDateFormat SimpleDateFormat can be used, see appendPattern(String). In practice, this simply parses the pattern and calls other methods on the builder.

    Specification for implementors

    This class is a mutable builder intended for use from a single thread.

    • Constructor Detail

      • DateTimeFormatterBuilder

        public DateTimeFormatterBuilder()
        Constructs a new instance of the builder.

    • Method Detail

      • getLocalizedDateTimePattern

        public static String getLocalizedDateTimePattern​(FormatStyle dateStyle,
                                                 FormatStyle timeStyle,
                                                 Chronology chrono,
                                                 Locale locale)
        Gets the formatting pattern for date and time styles for a locale and chronology. The locale and chronology are used to lookup the locale specific format for the requested dateStyle and/or timeStyle.
        Parameters:
        dateStyle - the FormatStyle for the date
        timeStyle - the FormatStyle for the time
        chrono - the Chronology, non-null
        locale - the locale, non-null
        Returns:
        the locale and Chronology specific formatting pattern
        Throws:
        IllegalArgumentException - if both dateStyle and timeStyle are null

      • parseCaseSensitive

        public DateTimeFormatterBuilder parseCaseSensitive()
        Changes the parse style to be case sensitive for the remainder of the formatter.

        Parsing can be case sensitive or insensitive - by default it is case sensitive. This method allows the case sensitivity setting of parsing to be changed.

        Calling this method changes the state of the builder such that all subsequent builder method calls will parse text in case sensitive mode. See parseCaseInsensitive() for the opposite setting. The parse case sensitive/insensitive methods may be called at any point in the builder, thus the parser can swap between case parsing modes multiple times during the parse.

        Since the default is case sensitive, this method should only be used after a previous call to #parseCaseInsensitive.

        Returns:
        this, for chaining, not null

      • parseCaseInsensitive

        public DateTimeFormatterBuilder parseCaseInsensitive()
        Changes the parse style to be case insensitive for the remainder of the formatter.

        Parsing can be case sensitive or insensitive - by default it is case sensitive. This method allows the case sensitivity setting of parsing to be changed.

        Calling this method changes the state of the builder such that all subsequent builder method calls will parse text in case sensitive mode. See parseCaseSensitive() for the opposite setting. The parse case sensitive/insensitive methods may be called at any point in the builder, thus the parser can swap between case parsing modes multiple times during the parse.

        Returns:
        this, for chaining, not null

      • parseStrict

        public DateTimeFormatterBuilder parseStrict()
        Changes the parse style to be strict for the remainder of the formatter.

        Parsing can be strict or lenient - by default its strict. This controls the degree of flexibility in matching the text and sign styles.

        When used, this method changes the parsing to be strict from this point onwards. As strict is the default, this is normally only needed after calling parseLenient(). The change will remain in force until the end of the formatter that is eventually constructed or until parseLenient is called.

        Returns:
        this, for chaining, not null

      • parseLenient

        public DateTimeFormatterBuilder parseLenient()
        Changes the parse style to be lenient for the remainder of the formatter. Note that case sensitivity is set separately to this method.

        Parsing can be strict or lenient - by default its strict. This controls the degree of flexibility in matching the text and sign styles. Applications calling this method should typically also call parseCaseInsensitive().

        When used, this method changes the parsing to be strict from this point onwards. The change will remain in force until the end of the formatter that is eventually constructed or until parseStrict is called.

        Returns:
        this, for chaining, not null

      • parseDefaulting

        public DateTimeFormatterBuilder parseDefaulting​(TemporalField field,
                                                long value)
        Appends a default value for a field to the formatter for use in parsing.

        This appends an instruction to the builder to inject a default value into the parsed result. This is especially useful in conjunction with optional parts of the formatter.

        For example, consider a formatter that parses the year, followed by an optional month, with a further optional day-of-month. Using such a formatter would require the calling code to check whether a full date, year-month or just a year had been parsed. This method can be used to default the month and day-of-month to a sensible value, such as the first of the month, allowing the calling code to always get a date.

        During formatting, this method has no effect.

        During parsing, the current state of the parse is inspected. If the specified field has no associated value, because it has not been parsed successfully at that point, then the specified value is injected into the parse result. Injection is immediate, thus the field-value pair will be visible to any subsequent elements in the formatter. As such, this method is normally called at the end of the builder.

        Parameters:
        field - the field to default the value of, not null
        value - the value to default the field to
        Returns:
        this, for chaining, not null

      • appendValue

        public DateTimeFormatterBuilder appendValue​(TemporalField field)
        Appends the value of a date-time field to the formatter using a normal output style.

        The value of the field will be output during a print. If the value cannot be obtained then an exception will be thrown.

        The value will be printed as per the normal print of an integer value. Only negative numbers will be signed. No padding will be added.

        The parser for a variable width value such as this normally behaves greedily, requiring one digit, but accepting as many digits as possible. This behavior can be affected by 'adjacent value parsing'. See appendValue(TemporalField, int) for full details.

        Parameters:
        field - the field to append, not null
        Returns:
        this, for chaining, not null

      • appendValue

        public DateTimeFormatterBuilder appendValue​(TemporalField field,
                                            int width)
        Appends the value of a date-time field to the formatter using a fixed width, zero-padded approach.

        The value of the field will be output during a print. If the value cannot be obtained then an exception will be thrown.

        The value will be zero-padded on the left. If the size of the value means that it cannot be printed within the width then an exception is thrown. If the value of the field is negative then an exception is thrown during printing.

        This method supports a special technique of parsing known as 'adjacent value parsing'. This technique solves the problem where a variable length value is followed by one or more fixed length values. The standard parser is greedy, and thus it would normally steal the digits that are needed by the fixed width value parsers that follow the variable width one.

        No action is required to initiate 'adjacent value parsing'. When a call to appendValue with a variable width is made, the builder enters adjacent value parsing setup mode. If the immediately subsequent method call or calls on the same builder are to this method, then the parser will reserve space so that the fixed width values can be parsed.

        For example, consider builder.appendValue(YEAR).appendValue(MONTH_OF_YEAR, 2); The year is a variable width parse of between 1 and 19 digits. The month is a fixed width parse of 2 digits. Because these were appended to the same builder immediately after one another, the year parser will reserve two digits for the month to parse. Thus, the text '201106' will correctly parse to a year of 2011 and a month of 6. Without adjacent value parsing, the year would greedily parse all six digits and leave nothing for the month.

        Adjacent value parsing applies to each set of fixed width not-negative values in the parser that immediately follow any kind of variable width value. Calling any other append method will end the setup of adjacent value parsing. Thus, in the unlikely event that you need to avoid adjacent value parsing behavior, simply add the appendValue to another DateTimeFormatterBuilder and add that to this builder.

        If adjacent parsing is active, then parsing must match exactly the specified number of digits in both strict and lenient modes. In addition, no positive or negative sign is permitted.

        Parameters:
        field - the field to append, not null
        width - the width of the printed field, from 1 to 19
        Returns:
        this, for chaining, not null
        Throws:
        IllegalArgumentException - if the width is invalid

      • appendValue

        public DateTimeFormatterBuilder appendValue​(TemporalField field,
                                            int minWidth,
                                            int maxWidth,
                                            SignStyle signStyle)
        Appends the value of a date-time field to the formatter providing full control over printing.

        The value of the field will be output during a print. If the value cannot be obtained then an exception will be thrown.

        This method provides full control of the numeric formatting, including zero-padding and the positive/negative sign.

        The parser for a variable width value such as this normally behaves greedily, accepting as many digits as possible. This behavior can be affected by 'adjacent value parsing'. See appendValue(TemporalField, int) for full details.

        In strict parsing mode, the minimum number of parsed digits is minWidth. In lenient parsing mode, the minimum number of parsed digits is one.

        If this method is invoked with equal minimum and maximum widths and a sign style of NOT_NEGATIVE then it delegates to appendValue(TemporalField,int). In this scenario, the printing and parsing behavior described there occur.

        Parameters:
        field - the field to append, not null
        minWidth - the minimum field width of the printed field, from 1 to 19
        maxWidth - the maximum field width of the printed field, from 1 to 19
        signStyle - the positive/negative output style, not null
        Returns:
        this, for chaining, not null
        Throws:
        IllegalArgumentException - if the widths are invalid

      • appendValueReduced

        public DateTimeFormatterBuilder appendValueReduced​(TemporalField field,
                                                   int width,
                                                   int maxWidth,
                                                   int baseValue)
        Appends the reduced value of a date-time field to the formatter.

        Since fields such as year vary by chronology, it is recommended to use the appendValueReduced(TemporalField, int, int, ChronoLocalDate) date} variant of this method in most cases. This variant is suitable for simple fields or working with only the ISO chronology.

        For formatting, the width and maxWidth are used to determine the number of characters to format. If they are equal then the format is fixed width. If the value of the field is within the range of the baseValue using width characters then the reduced value is formatted otherwise the value is truncated to fit maxWidth. The rightmost characters are output to match the width, left padding with zero.

        For strict parsing, the number of characters allowed by width to maxWidth are parsed. For lenient parsing, the number of characters must be at least 1 and less than 10. If the number of digits parsed is equal to width and the value is positive, the value of the field is computed to be the first number greater than or equal to the baseValue with the same least significant characters, otherwise the value parsed is the field value. This allows a reduced value to be entered for values in range of the baseValue and width and absolute values can be entered for values outside the range.

        For example, a base value of 1980 and a width of 2 will have valid values from 1980 to 2079. During parsing, the text "12" will result in the value 2012 as that is the value within the range where the last two characters are "12". By contrast, parsing the text "1915" will result in the value 1915.

        Parameters:
        field - the field to append, not null
        width - the field width of the printed and parsed field, from 1 to 10
        maxWidth - the maximum field width of the printed field, from 1 to 10
        baseValue - the base value of the range of valid values
        Returns:
        this, for chaining, not null
        Throws:
        IllegalArgumentException - if the width or base value is invalid

      • appendValueReduced

        public DateTimeFormatterBuilder appendValueReduced​(TemporalField field,
                                                   int width,
                                                   int maxWidth,
                                                   ChronoLocalDate baseDate)
        Appends the reduced value of a date-time field to the formatter.

        This is typically used for formatting and parsing a two digit year.

        The base date is used to calculate the full value during parsing. For example, if the base date is 1950-01-01 then parsed values for a two digit year parse will be in the range 1950-01-01 to 2049-12-31. Only the year would be extracted from the date, thus a base date of 1950-08-25 would also parse to the range 1950-01-01 to 2049-12-31. This behavior is necessary to support fields such as week-based-year or other calendar systems where the parsed value does not align with standard ISO years.

        The exact behavior is as follows. Parse the full set of fields and determine the effective chronology using the last chronology if it appears more than once. Then convert the base date to the effective chronology. Then extract the specified field from the chronology-specific base date and use it to determine the baseValue used below.

        For formatting, the width and maxWidth are used to determine the number of characters to format. If they are equal then the format is fixed width. If the value of the field is within the range of the baseValue using width characters then the reduced value is formatted otherwise the value is truncated to fit maxWidth. The rightmost characters are output to match the width, left padding with zero.

        For strict parsing, the number of characters allowed by width to maxWidth are parsed. For lenient parsing, the number of characters must be at least 1 and less than 10. If the number of digits parsed is equal to width and the value is positive, the value of the field is computed to be the first number greater than or equal to the baseValue with the same least significant characters, otherwise the value parsed is the field value. This allows a reduced value to be entered for values in range of the baseValue and width and absolute values can be entered for values outside the range.

        For example, a base value of 1980 and a width of 2 will have valid values from 1980 to 2079. During parsing, the text "12" will result in the value 2012 as that is the value within the range where the last two characters are "12". By contrast, parsing the text "1915" will result in the value 1915.

        Parameters:
        field - the field to append, not null
        width - the field width of the printed and parsed field, from 1 to 10
        maxWidth - the maximum field width of the printed field, from 1 to 10
        baseDate - the base date used to calculate the base value for the range of valid values in the parsed chronology, not null
        Returns:
        this, for chaining, not null
        Throws:
        IllegalArgumentException - if the width or base value is invalid

      • appendFraction

        public DateTimeFormatterBuilder appendFraction​(TemporalField field,
                                               int minWidth,
                                               int maxWidth,
                                               boolean decimalPoint)
        Appends the fractional value of a date-time field to the formatter.

        The fractional value of the field will be output including the preceding decimal point. The preceding value is not output. For example, the second-of-minute value of 15 would be output as .25.

        The width of the printed fraction can be controlled. Setting the minimum width to zero will cause no output to be generated. The printed fraction will have the minimum width necessary between the minimum and maximum widths - trailing zeroes are omitted. No rounding occurs due to the maximum width - digits are simply dropped.

        When parsing in strict mode, the number of parsed digits must be between the minimum and maximum width. When parsing in lenient mode, the minimum width is considered to be zero and the maximum is nine.

        If the value cannot be obtained then an exception will be thrown. If the value is negative an exception will be thrown. If the field does not have a fixed set of valid values then an exception will be thrown. If the field value in the date-time to be printed is invalid it cannot be printed and an exception will be thrown.

        Parameters:
        field - the field to append, not null
        minWidth - the minimum width of the field excluding the decimal point, from 0 to 9
        maxWidth - the maximum width of the field excluding the decimal point, from 1 to 9
        decimalPoint - whether to output the localized decimal point symbol
        Returns:
        this, for chaining, not null
        Throws:
        IllegalArgumentException - if the field has a variable set of valid values or either width is invalid

      • appendText

        public DateTimeFormatterBuilder appendText​(TemporalField field)
        Appends the text of a date-time field to the formatter using the full text style.

        The text of the field will be output during a print. The value must be within the valid range of the field. If the value cannot be obtained then an exception will be thrown. If the field has no textual representation, then the numeric value will be used.

        The value will be printed as per the normal print of an integer value. Only negative numbers will be signed. No padding will be added.

        Parameters:
        field - the field to append, not null
        Returns:
        this, for chaining, not null

      • appendText

        public DateTimeFormatterBuilder appendText​(TemporalField field,
                                           TextStyle textStyle)
        Appends the text of a date-time field to the formatter.

        The text of the field will be output during a print. The value must be within the valid range of the field. If the value cannot be obtained then an exception will be thrown. If the field has no textual representation, then the numeric value will be used.

        The value will be printed as per the normal print of an integer value. Only negative numbers will be signed. No padding will be added.

        Parameters:
        field - the field to append, not null
        textStyle - the text style to use, not null
        Returns:
        this, for chaining, not null

      • appendText

        public DateTimeFormatterBuilder appendText​(TemporalField field,
                                           Map<Long,​String> textLookup)
        Appends the text of a date-time field to the formatter using the specified map to supply the text.

        The standard text outputting methods use the localized text in the JDK. This method allows that text to be specified directly. The supplied map is not validated by the builder to ensure that printing or parsing is possible, thus an invalid map may throw an error during later use.

        Supplying the map of text provides considerable flexibility in printing and parsing. For example, a legacy application might require or supply the months of the year as "JNY", "FBY", "MCH" etc. These do not match the standard set of text for localized month names. Using this method, a map can be created which defines the connection between each value and the text: 

         Map<Long, String> map = new HashMap<>();
 map.put(1, "JNY");
 map.put(2, "FBY");
 map.put(3, "MCH");
 ...
 builder.appendText(MONTH_OF_YEAR, map);

        Other uses might be to output the value with a suffix, such as "1st", "2nd", "3rd", or as Roman numerals "I", "II", "III", "IV".

        During printing, the value is obtained and checked that it is in the valid range. If text is not available for the value then it is output as a number. During parsing, the parser will match against the map of text and numeric values.

        Parameters:
        field - the field to append, not null
        textLookup - the map from the value to the text
        Returns:
        this, for chaining, not null

      • appendInstant

        public DateTimeFormatterBuilder appendInstant()
        Appends an instant using ISO-8601 to the formatter, formatting fractional digits in groups of three.

        Instants have a fixed output format. They are converted to a date-time with a zone-offset of UTC and formatted using the standard ISO-8601 format. With this method, formatting nano-of-second outputs zero, three, six or nine digits as necessary. The localized decimal style is not used.

        The instant is obtained using INSTANT_SECONDS and optionally (@code NANO_OF_SECOND). The value of INSTANT_SECONDS may be outside the maximum range of LocalDateTime.

        The resolver style has no effect on instant parsing. The end-of-day time of '24:00' is handled as midnight at the start of the following day. The leap-second time of '23:59:59' is handled to some degree, see DateTimeFormatter.parsedLeapSecond() for full details.

        An alternative to this method is to format/parse the instant as a single epoch-seconds value. That is achieved using appendValue(INSTANT_SECONDS).

        Returns:
        this, for chaining, not null

      • appendInstant

        public DateTimeFormatterBuilder appendInstant​(int fractionalDigits)
        Appends an instant using ISO-8601 to the formatter with control over the number of fractional digits.

        Instants have a fixed output format, although this method provides some control over the fractional digits. They are converted to a date-time with a zone-offset of UTC and printed using the standard ISO-8601 format. The localized decimal style is not used.

        The fractionalDigits parameter allows the output of the fractional second to be controlled. Specifying zero will cause no fractional digits to be output. From 1 to 9 will output an increasing number of digits, using zero right-padding if necessary. The special value -1 is used to output as many digits as necessary to avoid any trailing zeroes.

        When parsing in strict mode, the number of parsed digits must match the fractional digits. When parsing in lenient mode, any number of fractional digits from zero to nine are accepted.

        The instant is obtained using INSTANT_SECONDS and optionally (@code NANO_OF_SECOND). The value of INSTANT_SECONDS may be outside the maximum range of LocalDateTime.

        The resolver style has no effect on instant parsing. The end-of-day time of '24:00' is handled as midnight at the start of the following day. The leap-second time of '23:59:59' is handled to some degree, see DateTimeFormatter.parsedLeapSecond() for full details.

        An alternative to this method is to format/parse the instant as a single epoch-seconds value. That is achieved using appendValue(INSTANT_SECONDS).

        Parameters:
        fractionalDigits - the number of fractional second digits to format with, from 0 to 9, or -1 to use as many digits as necessary
        Returns:
        this, for chaining, not null

      • appendOffsetId

        public DateTimeFormatterBuilder appendOffsetId()
        Appends the zone offset, such as '+01:00', to the formatter.

        This appends an instruction to print/parse the offset ID to the builder. This is equivalent to calling appendOffset("HH:MM:ss", "Z").

        Returns:
        this, for chaining, not null

      • appendOffset

        public DateTimeFormatterBuilder appendOffset​(String pattern,
                                             String noOffsetText)
        Appends the zone offset, such as '+01:00', to the formatter.

        This appends an instruction to print/parse the offset ID to the builder.

        During printing, the offset is obtained using a mechanism equivalent to querying the temporal with TemporalQueries.offset(). It will be printed using the format defined below. If the offset cannot be obtained then an exception is thrown unless the section of the formatter is optional.

        During parsing, the offset is parsed using the format defined below. If the offset cannot be parsed then an exception is thrown unless the section of the formatter is optional.

        The format of the offset is controlled by a pattern which must be one of the following:

        • +HH - hour only, ignoring minute and second
        • +HHmm - hour, with minute if non-zero, ignoring second, no colon
        • +HH:mm - hour, with minute if non-zero, ignoring second, with colon
        • +HHMM - hour and minute, ignoring second, no colon
        • +HH:MM - hour and minute, ignoring second, with colon
        • +HHMMss - hour and minute, with second if non-zero, no colon
        • +HH:MM:ss - hour and minute, with second if non-zero, with colon
        • +HHMMSS - hour, minute and second, no colon
        • +HH:MM:SS - hour, minute and second, with colon

        The "no offset" text controls what text is printed when the total amount of the offset fields to be output is zero. Example values would be 'Z', '+00:00', 'UTC' or 'GMT'. Three formats are accepted for parsing UTC - the "no offset" text, and the plus and minus versions of zero defined by the pattern.

        Parameters:
        pattern - the pattern to use, not null
        noOffsetText - the text to use when the offset is zero, not null
        Returns:
        this, for chaining, not null

      • appendLocalizedOffset

        public DateTimeFormatterBuilder appendLocalizedOffset​(TextStyle style)
        Appends the localized zone offset, such as 'GMT+01:00', to the formatter.

        This appends a localized zone offset to the builder, the format of the localized offset is controlled by the specified style to this method:

        • full - formats with localized offset text, such as 'GMT, 2-digit hour and minute field, optional second field if non-zero, and colon.
        • short - formats with localized offset text, such as 'GMT, hour without leading zero, optional 2-digit minute and second if non-zero, and colon.

        During formatting, the offset is obtained using a mechanism equivalent to querying the temporal with TemporalQueries.offset(). If the offset cannot be obtained then an exception is thrown unless the section of the formatter is optional.

        During parsing, the offset is parsed using the format defined above. If the offset cannot be parsed then an exception is thrown unless the section of the formatter is optional.

        Parameters:
        style - the format style to use, not null
        Returns:
        this, for chaining, not null
        Throws:
        IllegalArgumentException - if style is neither full nor short

      • appendZoneId

        public DateTimeFormatterBuilder appendZoneId()
        Appends the time-zone ID, such as 'Europe/Paris' or '+02:00', to the formatter.

        This appends an instruction to print/parse the zone ID to the builder. The zone ID is obtained in a strict manner suitable for ZonedDateTime. By contrast, OffsetDateTime does not have a zone ID suitable for use with this method, see appendZoneOrOffsetId().

        During printing, the zone is obtained using a mechanism equivalent to querying the temporal with TemporalQueries.zoneId(). It will be printed using the result of ZoneId.getId(). If the zone cannot be obtained then an exception is thrown unless the section of the formatter is optional.

        During parsing, the zone is parsed and must match a known zone or offset. If the zone cannot be parsed then an exception is thrown unless the section of the formatter is optional.

        Returns:
        this, for chaining, not null
        See Also:
        appendZoneRegionId()

      • appendZoneRegionId

        public DateTimeFormatterBuilder appendZoneRegionId()
        Appends the time-zone region ID, such as 'Europe/Paris', to the formatter, rejecting the zone ID if it is a ZoneOffset.

        This appends an instruction to print/parse the zone ID to the builder only if it is a region-based ID.

        During printing, the zone is obtained using a mechanism equivalent to querying the temporal with TemporalQueries.zoneId(). If the zone is a ZoneOffset or it cannot be obtained then an exception is thrown unless the section of the formatter is optional. If the zone is not an offset, then the zone will be printed using the zone ID from ZoneId.getId().

        During parsing, the zone is parsed and must match a known zone or offset. If the zone cannot be parsed then an exception is thrown unless the section of the formatter is optional. Note that parsing accepts offsets, whereas printing will never produce one, thus parsing is equivalent to appendZoneId.

        Returns:
        this, for chaining, not null
        See Also:
        appendZoneId()

      • appendZoneOrOffsetId

        public DateTimeFormatterBuilder appendZoneOrOffsetId()
        Appends the time-zone ID, such as 'Europe/Paris' or '+02:00', to the formatter, using the best available zone ID.

        This appends an instruction to print/parse the best available zone or offset ID to the builder. The zone ID is obtained in a lenient manner that first attempts to find a true zone ID, such as that on ZonedDateTime, and then attempts to find an offset, such as that on OffsetDateTime.

        During printing, the zone is obtained using a mechanism equivalent to querying the temporal with TemporalQueries.zone(). It will be printed using the result of ZoneId.getId(). If the zone cannot be obtained then an exception is thrown unless the section of the formatter is optional.

        During parsing, the zone is parsed and must match a known zone or offset. If the zone cannot be parsed then an exception is thrown unless the section of the formatter is optional.

        This method is identical to appendZoneId() except in the mechanism used to obtain the zone.

        Returns:
        this, for chaining, not null
        See Also:
        appendZoneId()

      • appendZoneText

        public DateTimeFormatterBuilder appendZoneText​(TextStyle textStyle)
        Appends the time-zone name, such as 'British Summer Time', to the formatter.

        This appends an instruction to print the textual name of the zone to the builder.

        During printing, the zone is obtained using a mechanism equivalent to querying the temporal with TemporalQueries.zoneId(). If the zone is a ZoneOffset it will be printed using the result of ZoneOffset.getId(). If the zone is not an offset, the textual name will be looked up for the locale set in the DateTimeFormatter. If the temporal object being printed represents an instant, then the text will be the summer or winter time text as appropriate. If the lookup for text does not find any suitable reuslt, then the ID will be printed instead. If the zone cannot be obtained then an exception is thrown unless the section of the formatter is optional.

        Parsing is not currently supported.

        Parameters:
        textStyle - the text style to use, not null
        Returns:
        this, for chaining, not null

      • appendZoneText

        public DateTimeFormatterBuilder appendZoneText​(TextStyle textStyle,
                                               Set<ZoneId> preferredZones)
        Appends the time-zone name, such as 'British Summer Time', to the formatter.

        This appends an instruction to format/parse the textual name of the zone to the builder.

        During formatting, the zone is obtained using a mechanism equivalent to querying the temporal with TemporalQueries.zoneId(). If the zone is a ZoneOffset it will be printed using the result of ZoneOffset.getId(). If the zone is not an offset, the textual name will be looked up for the locale set in the DateTimeFormatter. If the temporal object being printed represents an instant, then the text will be the summer or winter time text as appropriate. If the lookup for text does not find any suitable result, then the ID will be printed instead. If the zone cannot be obtained then an exception is thrown unless the section of the formatter is optional.

        During parsing, either the textual zone name, the zone ID or the offset is accepted. Many textual zone names are not unique, such as CST can be for both "Central Standard Time" and "China Standard Time". In this situation, the zone id will be determined by the region information from formatter's locale and the standard zone id for that area, for example, America/New_York for the America Eastern zone. This method also allows a set of preferred ZoneId to be specified for parsing. The matched preferred zone id will be used if the textual zone name being parsed is not unique.

        If the zone cannot be parsed then an exception is thrown unless the section of the formatter is optional.

        Parameters:
        textStyle - the text style to use, not null
        preferredZones - the set of preferred zone ids, not null
        Returns:
        this, for chaining, not null

      • appendChronologyId

        public DateTimeFormatterBuilder appendChronologyId()
        Appends the chronology ID to the formatter.

        The chronology ID will be output during a print. If the chronology cannot be obtained then an exception will be thrown.

        Returns:
        this, for chaining, not null

      • appendChronologyText

        public DateTimeFormatterBuilder appendChronologyText​(TextStyle textStyle)
        Appends the chronology ID, such as 'ISO' or 'ThaiBuddhist', to the formatter.

        This appends an instruction to format/parse the chronology ID to the builder.

        During printing, the chronology is obtained using a mechanism equivalent to querying the temporal with TemporalQueries.chronology(). It will be printed using the result of Chronology.getId(). If the chronology cannot be obtained then an exception is thrown unless the section of the formatter is optional.

        During parsing, the chronology is parsed and must match one of the chronologies in Chronology.getAvailableChronologies(). If the chronology cannot be parsed then an exception is thrown unless the section of the formatter is optional. The parser uses the case sensitive setting.

        Returns:
        this, for chaining, not null

      • appendLocalized

        public DateTimeFormatterBuilder appendLocalized​(FormatStyle dateStyle,
                                                FormatStyle timeStyle)
        Appends a localized date-time pattern to the formatter.

        This appends a localized section to the builder, suitable for outputting a date, time or date-time combination. The format of the localized section is lazily looked up based on four items:

        • the dateStyle specified to this method
        • the timeStyle specified to this method
        • the Locale of the DateTimeFormatter
        • the Chronology, selecting the best available

        During formatting, the chronology is obtained from the temporal object being formatted, which may have been overridden by DateTimeFormatter.withChronology(Chronology).

        During parsing, if a chronology has already been parsed, then it is used. Otherwise the default from DateTimeFormatter.withChronology(Chronology) is used, with IsoChronology as the fallback.

        Note that this method provides similar functionality to methods on DateFormat such as DateFormat.getDateTimeInstance(int, int).

        Parameters:
        dateStyle - the date style to use, null means no date required
        timeStyle - the time style to use, null means no time required
        Returns:
        this, for chaining, not null
        Throws:
        IllegalArgumentException - if both the date and time styles are null

      • appendLiteral

        public DateTimeFormatterBuilder appendLiteral​(char literal)
        Appends a character literal to the formatter.

        This character will be output during a print.

        Parameters:
        literal - the literal to append, not null
        Returns:
        this, for chaining, not null

      • appendLiteral

        public DateTimeFormatterBuilder appendLiteral​(String literal)
        Appends a string literal to the formatter.

        This string will be output during a print.

        If the literal is empty, nothing is added to the formatter.

        Parameters:
        literal - the literal to append, not null
        Returns:
        this, for chaining, not null

      • append

        public DateTimeFormatterBuilder append​(DateTimeFormatter formatter)
        Appends all the elements of a formatter to the builder.

        This method has the same effect as appending each of the constituent parts of the formatter directly to this builder.

        Parameters:
        formatter - the formatter to add, not null
        Returns:
        this, for chaining, not null

      • appendOptional

        public DateTimeFormatterBuilder appendOptional​(DateTimeFormatter formatter)
        Appends a formatter to the builder which will optionally print/parse.

        This method has the same effect as appending each of the constituent parts directly to this builder surrounded by an optionalStart() and optionalEnd().

        The formatter will print if data is available for all the fields contained within it. The formatter will parse if the string matches, otherwise no error is returned.

        Parameters:
        formatter - the formatter to add, not null
        Returns:
        this, for chaining, not null

      • appendPattern

        public DateTimeFormatterBuilder appendPattern​(String pattern)
        Appends the elements defined by the specified pattern to the builder.

        All letters 'A' to 'Z' and 'a' to 'z' are reserved as pattern letters. The characters '{' and '}' are reserved for future use. The characters '[' and ']' indicate optional patterns. The following pattern letters are defined: 

          Symbol  Meaning                     Presentation      Examples
  ------  -------                     ------------      -------
   G       era                         number/text       1; 01; AD; Anno Domini
   y       year                        year              2004; 04
   D       day-of-year                 number            189
   M       month-of-year               number/text       7; 07; Jul; July; J
   d       day-of-month                number            10

   Q       quarter-of-year             number/text       3; 03; Q3
   Y       week-based-year             year              1996; 96
   w       week-of-year                number            27
   W       week-of-month               number            27
   e       localized day-of-week       number            2; Tue; Tuesday; T
   E       day-of-week                 number/text       2; Tue; Tuesday; T
   F       week-of-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-am-pm (1-24)  number            0

   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
   z       time-zone name              zone-name         Pacific Standard Time; PST
   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

        The count of pattern letters determine 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.

        Number: If the count of letters is one, then the value is printed using the minimum number of digits and without padding as per appendValue(TemporalField). Otherwise, the count of digits is used as the width of the output field as per appendValue(TemporalField, int).

        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. When parsing in strict mode, the number of parsed digits must match the count of pattern letters. When parsing in lenient mode, the number of parsed digits must be at least the count of pattern letters, up to 9 digits.

        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. 

          Pattern     Equivalent builder methods
   VV          appendZoneId()

        Zone names: This outputs the display name of the time-zone ID. 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. 

          Pattern     Equivalent builder methods
   z           appendZoneText(TextStyle.SHORT)
   zz          appendZoneText(TextStyle.SHORT)
   zzz         appendZoneText(TextStyle.SHORT)
   zzzz        appendZoneText(TextStyle.FULL)

        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'. 

          Pattern     Equivalent builder methods
   X           appendOffset("+HHmm","Z")
   XX          appendOffset("+HHMM","Z")
   XXX         appendOffset("+HH:MM","Z")
   XXXX        appendOffset("+HHMMss","Z")
   XXXXX       appendOffset("+HH:MM:ss","Z")
   x           appendOffset("+HHmm","+00")
   xx          appendOffset("+HHMM","+0000")
   xxx         appendOffset("+HH:MM","+00:00")
   xxxx        appendOffset("+HHMMss","+0000")
   xxxxx       appendOffset("+HH:MM:ss","+00:00")

        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'. Four or more letters throws IllegalArgumentException. The output will be '+0000' when the offset is zero. 

          Pattern     Equivalent builder methods
   Z           appendOffset("+HHMM","+0000")
   ZZ          appendOffset("+HHMM","+0000")
   ZZZ         appendOffset("+HHMM","+0000")

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

        Note that the pattern string is similar, but not identical, to SimpleDateFormat. The pattern string is also similar, but not identical, to that defined by the Unicode Common Locale Data Repository (CLDR/LDML). Pattern letters 'E' and 'u' are merged, which changes the meaning of "E" and "EE" to be numeric. Pattern letters 'X' is aligned with Unicode CLDR/LDML, which affects pattern 'X'. Pattern letter 'y' and 'Y' parse years of two digits and more than 4 digits differently. Pattern letters 'n', 'A', 'N', 'I' and 'p' are added. Number types will reject large numbers.

        Parameters:
        pattern - the pattern to add, not null
        Returns:
        this, for chaining, not null
        Throws:
        IllegalArgumentException - if the pattern is invalid

      • padNext

        public DateTimeFormatterBuilder padNext​(int padWidth)
        Causes the next added printer/parser to pad to a fixed width using a space.

        This padding will pad to a fixed width using spaces.

        During formatting, the decorated element will be output and then padded to the specified width. An exception will be thrown during printing if the pad width is exceeded.

        During parsing, the padding and decorated element are parsed. If parsing is lenient, then the pad width is treated as a maximum. If parsing is case insensitive, then the pad character is matched ignoring case. The padding is parsed greedily. Thus, if the decorated element starts with the pad character, it will not be parsed.

        Parameters:
        padWidth - the pad width, 1 or greater
        Returns:
        this, for chaining, not null
        Throws:
        IllegalArgumentException - if pad width is too small

      • padNext

        public DateTimeFormatterBuilder padNext​(int padWidth,
                                        char padChar)
        Causes the next added printer/parser to pad to a fixed width.

        This padding is intended for padding other than zero-padding. Zero-padding should be achieved using the appendValue methods.

        During formatting, the decorated element will be output and then padded to the specified width. An exception will be thrown during printing if the pad width is exceeded.

        During parsing, the padding and decorated element are parsed. If parsing is lenient, then the pad width is treated as a maximum. If parsing is case insensitive, then the pad character is matched ignoring case. The padding is parsed greedily. Thus, if the decorated element starts with the pad character, it will not be parsed.

        Parameters:
        padWidth - the pad width, 1 or greater
        padChar - the pad character
        Returns:
        this, for chaining, not null
        Throws:
        IllegalArgumentException - if pad width is too small

      • optionalStart

        public DateTimeFormatterBuilder optionalStart()
        Mark the start of an optional section.

        The output of printing can include optional sections, which may be nested. An optional section is started by calling this method and ended by calling optionalEnd() or by ending the build process.

        All elements in the optional section are treated as optional. During printing, the section is only output if data is available in the TemporalAccessor for all the elements in the section. During parsing, the whole section may be missing from the parsed string.

        For example, consider a builder setup as builder.appendValue(HOUR_OF_DAY,2).optionalStart().appendValue(MINUTE_OF_HOUR,2). The optional section ends automatically at the end of the builder. During printing, the minute will only be output if its value can be obtained from the date-time. During parsing, the input will be successfully parsed whether the minute is present or not.

        Returns:
        this, for chaining, not null

      • optionalEnd

        public DateTimeFormatterBuilder optionalEnd()
        Ends an optional section.

        The output of printing can include optional sections, which may be nested. An optional section is started by calling optionalStart() and ended using this method (or at the end of the builder).

        Calling this method without having previously called optionalStart will throw an exception. Calling this method immediately after calling optionalStart has no effect on the formatter other than ending the (empty) optional section.

        All elements in the optional section are treated as optional. During printing, the section is only output if data is available in the TemporalAccessor for all the elements in the section. During parsing, the whole section may be missing from the parsed string.

        For example, consider a builder setup as builder.appendValue(HOUR_OF_DAY,2).optionalStart().appendValue(MINUTE_OF_HOUR,2).optionalEnd(). During printing, the minute will only be output if its value can be obtained from the date-time. During parsing, the input will be successfully parsed whether the minute is present or not.

        Returns:
        this, for chaining, not null
        Throws:
        IllegalStateException - if there was no previous call to optionalStart

      • toFormatter

        public DateTimeFormatter toFormatter()
        Completes this builder by creating the DateTimeFormatter using the default locale.

        This will create a formatter with the default locale. Numbers will be printed and parsed using the standard non-localized set of symbols.

        Calling this method will end any open optional sections by repeatedly calling optionalEnd() before creating the formatter.

        This builder can still be used after creating the formatter if desired, although the state may have been changed by calls to optionalEnd.

        Returns:
        the created formatter, not null

      • toFormatter

        public DateTimeFormatter toFormatter​(Locale locale)
        Completes this builder by creating the DateTimeFormatter using the specified locale.

        This will create a formatter with the specified locale. Numbers will be printed and parsed using the standard non-localized set of symbols.

        Calling this method will end any open optional sections by repeatedly calling optionalEnd() before creating the formatter.

        This builder can still be used after creating the formatter if desired, although the state may have been changed by calls to optionalEnd.

        Parameters:
        locale - the locale to use for formatting, not null
        Returns:
        the created formatter, not null