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"
In the future, we may add more forms, such as abbreviated/short forms (3 secs ago), and relative day periods ("yesterday afternoon"), etc.
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionstatic enum
Represents an absolute unit.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.static enum
Represents the unit for formatting a relative date. e.g "in 5 days" or "next year"static enum
Represents the unit for formatting a relative date. e.g "in 5 days" or "in 3 months"static enum
The formatting style -
Method Summary
Modifier and TypeMethodDescriptioncombineDateAndTime
(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.formatNumeric
(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".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".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.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.
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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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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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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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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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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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