Class Precision

  • All Implemented Interfaces:
    java.lang.Cloneable
    Direct Known Subclasses:
    CurrencyPrecision, FractionPrecision

    public abstract class Precision
    extends java.lang.Object
    implements java.lang.Cloneable
    A class that defines the rounding precision to be used when formatting numbers in NumberFormatter.

    To create a Precision, use one of the factory methods.

    See Also:
    NumberFormatter
    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      abstract void apply​(com.ibm.icu.impl.number.DecimalQuantity value)
      Deprecated.
      ICU 60 This API is ICU internal only.
      java.lang.Object clone()
      static CurrencyPrecision currency​(Currency.CurrencyUsage currencyUsage)
      Show numbers rounded and padded according to the rules for the currency unit.
      static FractionPrecision fixedFraction​(int minMaxFractionPlaces)
      Show numbers rounded if necessary to a certain number of fraction places (numerals after the decimal separator).
      static Precision fixedSignificantDigits​(int minMaxSignificantDigits)
      Show numbers rounded if necessary to a certain number of significant digits or significant figures.
      static Precision increment​(java.math.BigDecimal roundingIncrement)
      Show numbers rounded if necessary to the closest multiple of a certain rounding increment.
      static FractionPrecision integer()
      Show numbers rounded if necessary to the nearest integer.
      static FractionPrecision maxFraction​(int maxFractionPlaces)
      Show numbers rounded if necessary to a certain number of fraction places (numerals after the decimal separator).
      static Precision maxSignificantDigits​(int maxSignificantDigits)
      Show numbers rounded if necessary to a certain number of significant digits/figures.
      static FractionPrecision minFraction​(int minFractionPlaces)
      Always show at least a certain number of fraction places after the decimal separator, padding with zeros if necessary.
      static FractionPrecision minMaxFraction​(int minFractionPlaces, int maxFractionPlaces)
      Show numbers rounded if necessary to a certain number of fraction places (numerals after the decimal separator); in addition, always show at least a certain number of places after the decimal separator, padding with zeros if necessary.
      static Precision minMaxSignificantDigits​(int minSignificantDigits, int maxSignificantDigits)
      Show numbers rounded if necessary to a certain number of significant digits/figures; in addition, always show at least a certain number of significant digits, padding with zeros if necessary.
      static Precision minSignificantDigits​(int minSignificantDigits)
      Always show at least a certain number of significant digits/figures, padding with zeros if necessary.
      static Precision unlimited()
      Show all available digits to full precision.
      Precision withMode​(java.math.MathContext mathContext)
      Deprecated.
      This API is ICU internal only.
      • Methods inherited from class java.lang.Object

        equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Method Detail

      • unlimited

        public static Precision unlimited()
        Show all available digits to full precision.

        NOTE: When formatting a double, this method, along with minFraction(int) and minSignificantDigits(int), will trigger complex algorithm similar to Dragon4 to determine the low-order digits and the number of digits to display based on the value of the double. If the number of fraction places or significant digits can be bounded, consider using maxFraction(int) or maxSignificantDigits(int) instead to maximize performance. For more information, read the following blog post.

        http://www.serpentine.com/blog/2011/06/29/here-be-dragons-advances-in-problems-you-didnt-even-know-you-had/

        Returns:
        A Precision for chaining or passing to the NumberFormatter precision() setter.
        See Also:
        NumberFormatter
      • integer

        public static FractionPrecision integer()
        Show numbers rounded if necessary to the nearest integer.
        Returns:
        A FractionPrecision for chaining or passing to the NumberFormatter precision() setter.
        See Also:
        NumberFormatter
      • fixedFraction

        public static FractionPrecision fixedFraction​(int minMaxFractionPlaces)
        Show numbers rounded if necessary to a certain number of fraction places (numerals after the decimal separator). Additionally, pad with zeros to ensure that this number of places are always shown.

        Example output with minMaxFractionPlaces = 3:

        87,650.000
        8,765.000
        876.500
        87.650
        8.765
        0.876
        0.088
        0.009
        0.000 (zero)

        This method is equivalent to minMaxFraction(int, int) with both arguments equal.

        Parameters:
        minMaxFractionPlaces - The minimum and maximum number of numerals to display after the decimal separator (rounding if too long or padding with zeros if too short).
        Returns:
        A FractionPrecision for chaining or passing to the NumberFormatter precision() setter.
        See Also:
        NumberFormatter
      • minFraction

        public static FractionPrecision minFraction​(int minFractionPlaces)
        Always show at least a certain number of fraction places after the decimal separator, padding with zeros if necessary. Do not perform rounding (display numbers to their full precision).

        NOTE: If you are formatting doubles, see the performance note in unlimited().

        Parameters:
        minFractionPlaces - The minimum number of numerals to display after the decimal separator (padding with zeros if necessary).
        Returns:
        A FractionPrecision for chaining or passing to the NumberFormatter precision() setter.
        See Also:
        NumberFormatter
      • maxFraction

        public static FractionPrecision maxFraction​(int maxFractionPlaces)
        Show numbers rounded if necessary to a certain number of fraction places (numerals after the decimal separator). Unlike the other fraction rounding strategies, this strategy does not pad zeros to the end of the number.
        Parameters:
        maxFractionPlaces - The maximum number of numerals to display after the decimal mark (rounding if necessary).
        Returns:
        A FractionPrecision for chaining or passing to the NumberFormatter precision() setter.
        See Also:
        NumberFormatter
      • minMaxFraction

        public static FractionPrecision minMaxFraction​(int minFractionPlaces,
                                                       int maxFractionPlaces)
        Show numbers rounded if necessary to a certain number of fraction places (numerals after the decimal separator); in addition, always show at least a certain number of places after the decimal separator, padding with zeros if necessary.
        Parameters:
        minFractionPlaces - The minimum number of numerals to display after the decimal separator (padding with zeros if necessary).
        maxFractionPlaces - The maximum number of numerals to display after the decimal separator (rounding if necessary).
        Returns:
        A FractionPrecision for chaining or passing to the NumberFormatter precision() setter.
        See Also:
        NumberFormatter
      • fixedSignificantDigits

        public static Precision fixedSignificantDigits​(int minMaxSignificantDigits)
        Show numbers rounded if necessary to a certain number of significant digits or significant figures. Additionally, pad with zeros to ensure that this number of significant digits/figures are always shown.

        This method is equivalent to minMaxSignificantDigits(int, int) with both arguments equal.

        Parameters:
        minMaxSignificantDigits - The minimum and maximum number of significant digits to display (rounding if too long or padding with zeros if too short).
        Returns:
        A Precision for chaining or passing to the NumberFormatter precision() setter.
        See Also:
        NumberFormatter
      • minSignificantDigits

        public static Precision minSignificantDigits​(int minSignificantDigits)
        Always show at least a certain number of significant digits/figures, padding with zeros if necessary. Do not perform rounding (display numbers to their full precision).

        NOTE: If you are formatting doubles, see the performance note in unlimited().

        Parameters:
        minSignificantDigits - The minimum number of significant digits to display (padding with zeros if too short).
        Returns:
        A Precision for chaining or passing to the NumberFormatter precision() setter.
        See Also:
        NumberFormatter
      • maxSignificantDigits

        public static Precision maxSignificantDigits​(int maxSignificantDigits)
        Show numbers rounded if necessary to a certain number of significant digits/figures.
        Parameters:
        maxSignificantDigits - The maximum number of significant digits to display (rounding if too long).
        Returns:
        A Precision for chaining or passing to the NumberFormatter precision() setter.
        See Also:
        NumberFormatter
      • minMaxSignificantDigits

        public static Precision minMaxSignificantDigits​(int minSignificantDigits,
                                                        int maxSignificantDigits)
        Show numbers rounded if necessary to a certain number of significant digits/figures; in addition, always show at least a certain number of significant digits, padding with zeros if necessary.
        Parameters:
        minSignificantDigits - The minimum number of significant digits to display (padding with zeros if necessary).
        maxSignificantDigits - The maximum number of significant digits to display (rounding if necessary).
        Returns:
        A Precision for chaining or passing to the NumberFormatter precision() setter.
        See Also:
        NumberFormatter
      • increment

        public static Precision increment​(java.math.BigDecimal roundingIncrement)
        Show numbers rounded if necessary to the closest multiple of a certain rounding increment. For example, if the rounding increment is 0.5, then round 1.2 to 1 and round 1.3 to 1.5.

        In order to ensure that numbers are padded to the appropriate number of fraction places, set the scale on the rounding increment BigDecimal. For example, to round to the nearest 0.5 and always display 2 numerals after the decimal separator (to display 1.2 as "1.00" and 1.3 as "1.50"), you can run:

         Precision.increment(new BigDecimal("0.50"))
         

        For more information on the scale of Java BigDecimal, see BigDecimal.scale().

        Parameters:
        roundingIncrement - The increment to which to round numbers.
        Returns:
        A Precision for chaining or passing to the NumberFormatter precision() setter.
        See Also:
        NumberFormatter
      • currency

        public static CurrencyPrecision currency​(Currency.CurrencyUsage currencyUsage)
        Show numbers rounded and padded according to the rules for the currency unit. The most common rounding precision settings for currencies include Precision.fixedFraction(2), Precision.integer(), and Precision.increment(0.05) for cash transactions ("nickel rounding").

        The exact rounding details will be resolved at runtime based on the currency unit specified in the NumberFormatter chain. To round according to the rules for one currency while displaying the symbol for another currency, the withCurrency() method can be called on the return value of this method.

        Parameters:
        currencyUsage - Either STANDARD (for digital transactions) or CASH (for transactions where the rounding increment may be limited by the available denominations of cash or coins).
        Returns:
        A CurrencyPrecision for chaining or passing to the NumberFormatter precision() setter.
        See Also:
        NumberFormatter
      • withMode

        @Deprecated
        public Precision withMode​(java.math.MathContext mathContext)
        Deprecated.
        This API is ICU internal only.
        Sets a MathContext to use on this Precision.
      • clone

        public java.lang.Object clone()
        Overrides:
        clone in class java.lang.Object
      • apply

        @Deprecated
        public abstract void apply​(com.ibm.icu.impl.number.DecimalQuantity value)
        Deprecated.
        ICU 60 This API is ICU internal only.