Class RelativeDateTimeFormatter
- relative dates with a quantity e.g "in 5 days"
- relative dates without a quantity e.g "next Tuesday"
This API is very basic and is intended to be a building block for more fancy APIs. The caller tells it exactly what to display in a locale independent way. While this class automatically provides the correct plural forms, the grammatical form is otherwise as neutral as possible. It is the caller's responsibility to handle cut-off logic such as deciding between displaying "in 7 days" or "in 1 week." This API supports relative dates involving one single unit. This API does not support relative dates involving compound units. e.g "in 5 days and 4 hours" nor does it support parsing. This class is both immutable and thread-safe.
Here are some examples of use:
RelativeDateTimeFormatter fmt = RelativeDateTimeFormatter.getInstance(); fmt.format(1, Direction.NEXT, RelativeUnit.DAYS); // "in 1 day" fmt.format(3, Direction.NEXT, RelativeUnit.DAYS); // "in 3 days" fmt.format(3.2, Direction.LAST, RelativeUnit.YEARS); // "3.2 years ago" fmt.format(Direction.LAST, AbsoluteUnit.SUNDAY); // "last Sunday" fmt.format(Direction.THIS, AbsoluteUnit.SUNDAY); // "this Sunday" fmt.format(Direction.NEXT, AbsoluteUnit.SUNDAY); // "next Sunday" fmt.format(Direction.PLAIN, AbsoluteUnit.SUNDAY); // "Sunday" fmt.format(Direction.LAST, AbsoluteUnit.DAY); // "yesterday" fmt.format(Direction.THIS, AbsoluteUnit.DAY); // "today" fmt.format(Direction.NEXT, AbsoluteUnit.DAY); // "tomorrow" fmt.format(Direction.PLAIN, AbsoluteUnit.NOW); // "now"
The Style parameter allows selection of different length styles: LONG ("3 seconds ago"), SHORT ("3 sec. ago"), NARROW ("3s ago"). In the future, we may add more forms, such as relative day periods ("yesterday afternoon"), etc.
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionstatic enum
Represents an absolute unit.private static class
static enum
Represents a direction for an absolute unit e.g "Next Tuesday" or "Last Tuesday"static class
Field constants used when accessing field information for relative datetime strings in FormattedValue.static class
Represents the result of a formatting operation of a relative datetime.private static class
private static class
static enum
Represents the unit for formatting a relative date.static enum
Represents the unit for formatting a relative date.private static final class
Sink for enumerating all of the relative data time formatter names.static enum
The formatting style -
Field Summary
FieldsModifier and TypeFieldDescriptionprivate final BreakIterator
private static final RelativeDateTimeFormatter.Cache
private final DisplayContext
private final String
private final DateFormatSymbols
private static final RelativeDateTimeFormatter.Style[]
private final ULocale
private final NumberFormat
private final EnumMap
<RelativeDateTimeFormatter.Style, EnumMap<RelativeDateTimeFormatter.RelativeUnit, String[][]>> private final PluralRules
private final EnumMap
<RelativeDateTimeFormatter.Style, EnumMap<RelativeDateTimeFormatter.AbsoluteUnit, EnumMap<RelativeDateTimeFormatter.Direction, String>>> private final RelativeDateTimeFormatter.Style
private int[]
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Constructor Summary
ConstructorsModifierConstructorDescriptionprivate
RelativeDateTimeFormatter
(EnumMap<RelativeDateTimeFormatter.Style, EnumMap<RelativeDateTimeFormatter.AbsoluteUnit, EnumMap<RelativeDateTimeFormatter.Direction, String>>> qualitativeUnitMap, EnumMap<RelativeDateTimeFormatter.Style, EnumMap<RelativeDateTimeFormatter.RelativeUnit, String[][]>> patternMap, String combinedDateAndTime, PluralRules pluralRules, NumberFormat numberFormat, RelativeDateTimeFormatter.Style style, DisplayContext capitalizationContext, BreakIterator breakIterator, ULocale locale) -
Method Summary
Modifier and TypeMethodDescriptionprivate String
adjustForContext
(String originalFormattedString) private void
combineDateAndTime
(String relativeDateString, String timeString) Combines a relative date string and a time string in this object's locale.format
(double quantity, RelativeDateTimeFormatter.Direction direction, RelativeDateTimeFormatter.RelativeUnit unit) Formats a relative date with a quantity such as "in 5 days" or "3 months ago".format
(double offset, RelativeDateTimeFormatter.RelativeDateTimeUnit unit) Format a combination of RelativeDateTimeUnit and numeric offset using a text style if possible, e.g.Formats a relative date without a quantity.private String
formatAbsoluteImpl
(RelativeDateTimeFormatter.Direction direction, RelativeDateTimeFormatter.AbsoluteUnit unit) Implementation method for format and formatToValue with AbsoluteUnitprivate FormattedStringBuilder
formatImpl
(double quantity, RelativeDateTimeFormatter.Direction direction, RelativeDateTimeFormatter.RelativeUnit unit) Implementation method for format and formatToValue with RelativeUnitformatNumeric
(double offset, RelativeDateTimeFormatter.RelativeDateTimeUnit unit) Format a combination of RelativeDateTimeUnit and numeric offset using a numeric style, e.g.private FormattedStringBuilder
formatNumericImpl
(double offset, RelativeDateTimeFormatter.RelativeDateTimeUnit unit) Implementation method for formatNumeric and formatNumericToValueformatNumericToValue
(double offset, RelativeDateTimeFormatter.RelativeDateTimeUnit unit) Format a combination of RelativeDateTimeUnit and numeric offset using a numeric style, e.g.private CharSequence
formatRelativeImpl
(double offset, RelativeDateTimeFormatter.RelativeDateTimeUnit unit) Implementation method for format and formatToValue with RelativeDateTimeUnit.formatToValue
(double quantity, RelativeDateTimeFormatter.Direction direction, RelativeDateTimeFormatter.RelativeUnit unit) Formats a relative date with a quantity such as "in 5 days" or "3 months ago".formatToValue
(double offset, RelativeDateTimeFormatter.RelativeDateTimeUnit unit) Format a combination of RelativeDateTimeUnit and numeric offset using a text style if possible, e.g.formatToValue
(RelativeDateTimeFormatter.Direction direction, RelativeDateTimeFormatter.AbsoluteUnit unit) Formats a relative date without a quantity.private String
getAbsoluteUnitString
(RelativeDateTimeFormatter.Style style, RelativeDateTimeFormatter.AbsoluteUnit unit, RelativeDateTimeFormatter.Direction direction) Gets the string value from qualitativeUnitMap with fallback based on style.Return capitalization context.Return stylestatic RelativeDateTimeFormatter
Returns a RelativeDateTimeFormatter for the default locale.static RelativeDateTimeFormatter
getInstance
(ULocale locale) Returns a RelativeDateTimeFormatter for a particular locale.static RelativeDateTimeFormatter
getInstance
(ULocale locale, NumberFormat nf) Returns a RelativeDateTimeFormatter for a particular locale that uses a particular NumberFormat object.static RelativeDateTimeFormatter
getInstance
(ULocale locale, NumberFormat nf, RelativeDateTimeFormatter.Style style, DisplayContext capitalizationContext) Returns a RelativeDateTimeFormatter for a particular locale that uses a particular NumberFormat object, style, and capitalization contextstatic RelativeDateTimeFormatter
getInstance
(Locale locale) Returns a RelativeDateTimeFormatter for a particularLocale
.static RelativeDateTimeFormatter
getInstance
(Locale locale, NumberFormat nf) Returns a RelativeDateTimeFormatter for a particularLocale
that uses a particular NumberFormat object.Returns a copy of the NumberFormat this object is using.private String
getRelativeUnitPattern
(RelativeDateTimeFormatter.Style style, RelativeDateTimeFormatter.RelativeUnit unit, int pastFutureIndex, StandardPlural pluralForm) private String
getRelativeUnitPluralPattern
(RelativeDateTimeFormatter.Style style, RelativeDateTimeFormatter.RelativeUnit unit, int pastFutureIndex, StandardPlural pluralForm) private static RelativeDateTimeFormatter.Direction
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Field Details
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styleToDateFormatSymbolsWidth
private int[] styleToDateFormatSymbolsWidth -
qualitativeUnitMap
private final EnumMap<RelativeDateTimeFormatter.Style,EnumMap<RelativeDateTimeFormatter.AbsoluteUnit, qualitativeUnitMapEnumMap<RelativeDateTimeFormatter.Direction, String>>> -
patternMap
private final EnumMap<RelativeDateTimeFormatter.Style,EnumMap<RelativeDateTimeFormatter.RelativeUnit, patternMapString[][]>> -
combinedDateAndTime
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pluralRules
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numberFormat
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style
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capitalizationContext
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breakIterator
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locale
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dateFormatSymbols
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fallbackCache
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cache
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Constructor Details
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RelativeDateTimeFormatter
private RelativeDateTimeFormatter(EnumMap<RelativeDateTimeFormatter.Style, EnumMap<RelativeDateTimeFormatter.AbsoluteUnit, EnumMap<RelativeDateTimeFormatter.Direction, String>>> qualitativeUnitMap, EnumMap<RelativeDateTimeFormatter.Style, EnumMap<RelativeDateTimeFormatter.RelativeUnit, String[][]>> patternMap, String combinedDateAndTime, PluralRules pluralRules, NumberFormat numberFormat, RelativeDateTimeFormatter.Style style, DisplayContext capitalizationContext, BreakIterator breakIterator, ULocale locale)
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Method Details
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getInstance
Returns a RelativeDateTimeFormatter for the default locale. -
getInstance
Returns a RelativeDateTimeFormatter for a particular locale.- Parameters:
locale
- the locale.- Returns:
- An instance of RelativeDateTimeFormatter.
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getInstance
Returns a RelativeDateTimeFormatter for a particularLocale
.- Parameters:
locale
- theLocale
.- Returns:
- An instance of RelativeDateTimeFormatter.
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getInstance
Returns a RelativeDateTimeFormatter for a particular locale that uses a particular NumberFormat object.- Parameters:
locale
- the localenf
- the number format object. It is defensively copied to ensure thread-safety and immutability of this class.- Returns:
- An instance of RelativeDateTimeFormatter.
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getInstance
public static RelativeDateTimeFormatter getInstance(ULocale locale, NumberFormat nf, RelativeDateTimeFormatter.Style style, DisplayContext capitalizationContext) Returns a RelativeDateTimeFormatter for a particular locale that uses a particular NumberFormat object, style, and capitalization context- Parameters:
locale
- the localenf
- the number format object. It is defensively copied to ensure thread-safety and immutability of this class. May be null.style
- the style.capitalizationContext
- the capitalization context.
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getInstance
Returns a RelativeDateTimeFormatter for a particularLocale
that uses a particular NumberFormat object.- Parameters:
locale
- theLocale
nf
- the number format object. It is defensively copied to ensure thread-safety and immutability of this class.- Returns:
- An instance of RelativeDateTimeFormatter.
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format
public String format(double quantity, RelativeDateTimeFormatter.Direction direction, RelativeDateTimeFormatter.RelativeUnit unit) Formats a relative date with a quantity such as "in 5 days" or "3 months ago". This method returns a String. To get more information about the formatting result, use formatToValue().- Parameters:
quantity
- The numerical amount e.g 5. This value is formatted according to this object'sNumberFormat
object.direction
- NEXT means a future relative date; LAST means a past relative date.unit
- the unit e.g day? month? year?- Returns:
- the formatted string
- Throws:
IllegalArgumentException
- if direction is something other than NEXT or LAST.
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formatToValue
public RelativeDateTimeFormatter.FormattedRelativeDateTime formatToValue(double quantity, RelativeDateTimeFormatter.Direction direction, RelativeDateTimeFormatter.RelativeUnit unit) Formats a relative date with a quantity such as "in 5 days" or "3 months ago". This method returns a FormattedRelativeDateTime, which exposes more information than the String returned by format().- Parameters:
quantity
- The numerical amount e.g 5. This value is formatted according to this object'sNumberFormat
object.direction
- NEXT means a future relative date; LAST means a past relative date.unit
- the unit e.g day? month? year?- Returns:
- the formatted relative datetime
- Throws:
IllegalArgumentException
- if direction is something other than NEXT or LAST.
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formatImpl
private FormattedStringBuilder formatImpl(double quantity, RelativeDateTimeFormatter.Direction direction, RelativeDateTimeFormatter.RelativeUnit unit) Implementation method for format and formatToValue with RelativeUnit -
formatNumeric
Format a combination of RelativeDateTimeUnit and numeric offset using a numeric style, e.g. "1 week ago", "in 1 week", "5 weeks ago", "in 5 weeks". This method returns a String. To get more information about the formatting result, use formatNumericToValue().- Parameters:
offset
- The signed offset for the specified unit. This will be formatted according to this object's NumberFormat object.unit
- The unit to use when formatting the relative date, e.g. RelativeDateTimeUnit.WEEK, RelativeDateTimeUnit.FRIDAY.- Returns:
- The formatted string (may be empty in case of error)
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formatNumericToValue
public RelativeDateTimeFormatter.FormattedRelativeDateTime formatNumericToValue(double offset, RelativeDateTimeFormatter.RelativeDateTimeUnit unit) Format a combination of RelativeDateTimeUnit and numeric offset using a numeric style, e.g. "1 week ago", "in 1 week", "5 weeks ago", "in 5 weeks". This method returns a FormattedRelativeDateTime, which exposes more information than the String returned by formatNumeric().- Parameters:
offset
- The signed offset for the specified unit. This will be formatted according to this object's NumberFormat object.unit
- The unit to use when formatting the relative date, e.g. RelativeDateTimeUnit.WEEK, RelativeDateTimeUnit.FRIDAY.- Returns:
- The formatted string (may be empty in case of error)
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formatNumericImpl
private FormattedStringBuilder formatNumericImpl(double offset, RelativeDateTimeFormatter.RelativeDateTimeUnit unit) Implementation method for formatNumeric and formatNumericToValue -
format
public String format(RelativeDateTimeFormatter.Direction direction, RelativeDateTimeFormatter.AbsoluteUnit unit) Formats a relative date without a quantity. This method returns a String. To get more information about the formatting result, use formatToValue().- Parameters:
direction
- NEXT, LAST, THIS, etc.unit
- e.g SATURDAY, DAY, MONTH- Returns:
- the formatted string. If direction has a value that is documented as not being fully supported in every locale (for example NEXT_2 or LAST_2) then this function may return null to signal that no formatted string is available.
- Throws:
IllegalArgumentException
- if the direction is incompatible with unit this can occur with NOW which can only take PLAIN.
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formatToValue
public RelativeDateTimeFormatter.FormattedRelativeDateTime formatToValue(RelativeDateTimeFormatter.Direction direction, RelativeDateTimeFormatter.AbsoluteUnit unit) Formats a relative date without a quantity. This method returns a FormattedRelativeDateTime, which exposes more information than the String returned by format().- Parameters:
direction
- NEXT, LAST, THIS, etc.unit
- e.g SATURDAY, DAY, MONTH- Returns:
- the formatted string. If direction has a value that is documented as not being fully supported in every locale (for example NEXT_2 or LAST_2) then this function may return null to signal that no formatted string is available.
- Throws:
IllegalArgumentException
- if the direction is incompatible with unit this can occur with NOW which can only take PLAIN.
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formatAbsoluteImpl
private String formatAbsoluteImpl(RelativeDateTimeFormatter.Direction direction, RelativeDateTimeFormatter.AbsoluteUnit unit) Implementation method for format and formatToValue with AbsoluteUnit -
format
Format a combination of RelativeDateTimeUnit and numeric offset using a text style if possible, e.g. "last week", "this week", "next week", "yesterday", "tomorrow". Falls back to numeric style if no appropriate text term is available for the specified offset in the object’s locale. This method returns a String. To get more information about the formatting result, use formatToValue().- Parameters:
offset
- The signed offset for the specified field.unit
- The unit to use when formatting the relative date, e.g. RelativeDateTimeUnit.WEEK, RelativeDateTimeUnit.FRIDAY.- Returns:
- The formatted string (may be empty in case of error)
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formatToValue
public RelativeDateTimeFormatter.FormattedRelativeDateTime formatToValue(double offset, RelativeDateTimeFormatter.RelativeDateTimeUnit unit) Format a combination of RelativeDateTimeUnit and numeric offset using a text style if possible, e.g. "last week", "this week", "next week", "yesterday", "tomorrow". Falls back to numeric style if no appropriate text term is available for the specified offset in the object’s locale. This method returns a FormattedRelativeDateTime, which exposes more information than the String returned by format().- Parameters:
offset
- The signed offset for the specified field.unit
- The unit to use when formatting the relative date, e.g. RelativeDateTimeUnit.WEEK, RelativeDateTimeUnit.FRIDAY.- Returns:
- The formatted string (may be empty in case of error)
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formatRelativeImpl
private CharSequence formatRelativeImpl(double offset, RelativeDateTimeFormatter.RelativeDateTimeUnit unit) Implementation method for format and formatToValue with RelativeDateTimeUnit. -
getAbsoluteUnitString
private String getAbsoluteUnitString(RelativeDateTimeFormatter.Style style, RelativeDateTimeFormatter.AbsoluteUnit unit, RelativeDateTimeFormatter.Direction direction) Gets the string value from qualitativeUnitMap with fallback based on style. -
combineDateAndTime
Combines a relative date string and a time string in this object's locale. This is done with the same date-time separator used for the default calendar in this locale.- Parameters:
relativeDateString
- the relative date e.g 'yesterday'timeString
- the time e.g '3:45'- Returns:
- the date and time concatenated according to the default calendar in this locale e.g 'yesterday, 3:45'
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getNumberFormat
Returns a copy of the NumberFormat this object is using.- Returns:
- A copy of the NumberFormat.
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getCapitalizationContext
Return capitalization context.- Returns:
- The capitalization context.
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getFormatStyle
Return style- Returns:
- The formatting style.
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adjustForContext
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checkNoAdjustForContext
private void checkNoAdjustForContext() -
getRelativeUnitPluralPattern
private String getRelativeUnitPluralPattern(RelativeDateTimeFormatter.Style style, RelativeDateTimeFormatter.RelativeUnit unit, int pastFutureIndex, StandardPlural pluralForm) -
getRelativeUnitPattern
private String getRelativeUnitPattern(RelativeDateTimeFormatter.Style style, RelativeDateTimeFormatter.RelativeUnit unit, int pastFutureIndex, StandardPlural pluralForm) -
keyToDirection
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