org.salespointframework.quantity

Class BasicRoundingStrategy

java.lang.Object

org.salespointframework.quantity.BasicRoundingStrategy

All Implemented Interfaces:

Serializable, RoundingStrategy

public class BasicRoundingStrategy
extends Object
implements RoundingStrategy, Serializable

This implementation of a RoundingStrategy offers to ways to describe a rounding operation: using the decimal places after (or before) the decimal delimiter and using a rounding step.
The two methods are related: roundingStep = 10(-numberOfDigits)
For example, specifying 4 as numberOfDigits results in a roundingStep of 0.0001. To retain 4 digits after the decimal delimiter, the value is rounded to the next multiple of 0.0001.

Which multiple is chosen - the higher or lower valued one - is determined by the RoundingMode.

For either parameter - roundingStep and numberOfDigits - positive and negative values are allowed.

Positive values of numberOfDigits designate decimal places after the radix delimiter, negative values designate decimal places before the radix delimiter. A value of -1, for example, will result in rounding to whole 10s, -2 to whole 100s, and so forth. A value of zero designates integer values.

Using negative values of roundingStep will yield the same result as a positive roundingStep of the same magnitude would have. Using zero as roundingStep is illegal and will result in an ArithmeticException at runtime, when the BasicRoundingStrategy is used.

Author:

Hannes Weisbach

See Also:

Serialized Form

Field Summary

Fields inherited from interface org.salespointframework.quantity.RoundingStrategy

MONETARY_ROUNDING, ROUND_ONE

Constructor Summary

Constructors

Constructor and Description
BasicRoundingStrategy(BigDecimal roundingStep, RoundingMode roundingMode) Instantiates a new BasicRoundingStrategy using a rounding step and a rounding mode.
BasicRoundingStrategy(int numberOfDigits, RoundingMode roundingMode) Instantiates a new BasicRoundingStrategy using the number of digits after (or before) the decimal delimiter and a rounding mode.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object o) Two instances of BasicRoundingStrategy are equal, if and only if their roundingStep attributes are numerically equal and if their roundingMode attributes are equal.
RoundingMode	getRoundingMode() Returns the RoundingMode used by this instance of BasicRoundingStrategy.
BigDecimal	getRoundingStep() Returns the step, to which is rounded.
int	hashcode() Returns a hash code for this RoundingStrategy object.
int	hashCode()
BigDecimal	round(BigDecimal amount) Rounds the given BigDecimal instance amount with a specific strategy.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BasicRoundingStrategy

public BasicRoundingStrategy(BigDecimal roundingStep,
                             RoundingMode roundingMode)

Instantiates a new BasicRoundingStrategy using a rounding step and a rounding mode. Using both parameters a value is rounded in the direction specified by roundingMode to the next multiple of roundingStep. Usually, a rounding step is a positive value. However, a negative rounding step can also be specified, which gives the same results as a positive rounding step of equal value. A roundingStep of value zero may not be specified and will result in an ArithmeticException, if the RoundingStrategy is used.

Parameters:

roundingStep - multiple to which is rounded

roundingMode - mode or direction in which is rounded

BasicRoundingStrategy

public BasicRoundingStrategy(int numberOfDigits,
                             RoundingMode roundingMode)

Instantiates a new BasicRoundingStrategy using the number of digits after (or before) the decimal delimiter and a rounding mode. roundingMode specifies the direction in which is rounded, whereas numberOfDigits specifies the precision to which is rounded. Positive values for numberOfDigits describe decimal places after the decimal delimiter, negative values before the decimal delimiter. A value of zero rounds to integer values.

Parameters:

numberOfDigits - rounding precision in decimal places before (negative) or after (positive) the decimal delimiter

roundingMode - mode or direction in which is rounded

Method Detail

round

public BigDecimal round(BigDecimal amount)

Description copied from interface: RoundingStrategy

Rounds the given BigDecimal instance amount with a specific strategy. Because BigDecimal is immutable, a new instance with a rounded value is returned.

Specified by:

round in interface RoundingStrategy

Parameters:

amount - The BigDecimal instance which should be rounded.

Returns:

A new BigDecimal instance which has a rounded value.

equals

public boolean equals(Object o)

Two instances of BasicRoundingStrategy are equal, if and only if their roundingStep attributes are numerically equal and if their roundingMode attributes are equal.

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

hashcode

public final int hashcode()

Returns a hash code for this RoundingStrategy object. The hash code is the exclusive OR of the roundingStep, and the hash code of roundingMode objects.

Returns:

hash code for this RoundingStrategy object.

getRoundingStep

public BigDecimal getRoundingStep()

Returns the step, to which is rounded. After rounding, the result is divisible by roundingStep with an integral result.

Returns:

step to which is rounded

getRoundingMode

public RoundingMode getRoundingMode()

Returns the RoundingMode used by this instance of BasicRoundingStrategy.

Returns:

RoundingMode used for rounding.