com.jstatcom.model
Class NumberRange

java.lang.Object
  com.jstatcom.model.NumberRange

public final class NumberRange
extends java.lang.Object

This class specifies an interval defined by two numbers and a type and provides methods to validate numbers and other NumberRange instances against it.

The class is immutable by design, see (Joshua Bloch, "Effective Java", Item 13).

Author:

Markus Kraetzig

Field Summary

double	lowerBound The lower bound of this range.
NumberRangeTypes	rangeType The type of this range, which is either OPEN, CLOSED, LEFT_OPEN or RIGHT_OPEN.
double	upperBound The upper bound of this range.

Constructor Summary

NumberRange()
Creates an open range with (-Infinity,+Infinity).

NumberRange(double lowerBoundNew, double upperBoundNew, NumberRangeTypes rangeType)
Creates a range according to the given bounds and the type.

Method Summary

double	defaultNumber() Finds a number that is valid for this range.
NumberRange	defaultNumberRange() Finds a number range that is enclosed by this range.
java.lang.String	encloses(double number) Tests whether a given number is enclosed in this range and returns a formatted message if not.
java.lang.String	encloses(double number, int precision, java.text.NumberFormat formatter) Tests whether a given number is enclosed in this range and returns a formatted message if not.
java.lang.String	encloses(NumberRange numberRange) Tests whether a given range is completely enclosed within this range and returns a formatted message if not.
boolean	equals(java.lang.Object o) Provides logical equals check.
java.lang.String	formattedString(java.text.NumberFormat formatter) Gets a string representation of this range with a special formatter.
int	hashCode() Overrides hashCode, because equals was overwritten.
double	lowerBound() Gets the lower bound for this range.
java.lang.String	toString() Gets string representation of this range.
NumberRangeTypes	type() Gets the interval type for this range.
double	upperBound() Gets the upper bound for this range.
static NumberRange	valueOf(java.lang.String exp) Static initialized that creates a NumberRange from a string representation.

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Field Detail

lowerBound

public final double lowerBound

The lower bound of this range.

upperBound

public final double upperBound

The upper bound of this range.

rangeType

public final NumberRangeTypes rangeType

The type of this range, which is either OPEN, CLOSED, LEFT_OPEN or RIGHT_OPEN.

Constructor Detail

NumberRange

public NumberRange()

Creates an open range with (-Infinity,+Infinity).

NumberRange

public NumberRange(double lowerBoundNew,
                   double upperBoundNew,
                   NumberRangeTypes rangeType)

Creates a range according to the given bounds and the type.

Parameters:

lowerBoundNew - the lower bound of the interval

upperBoundNew - the upper bound of the interval

rangeType - the interval type to be created

Throws:

java.lang.IllegalArgumentException - if:

• lowerBound > upperBound
• lowerBound == upperBound and rangeType is not closed
• lowerBound == -Infinity and rangeType is not left open
• upperBound == +Infinity and rangeType is not right open
• lowerBound == +Infinity
• upperBound == -Infinity
• upperBound or lowerBound is equal to NaN
• rangeType == null

Method Detail

defaultNumber

public double defaultNumber()

Finds a number that is valid for this range.

Returns:

a valid number within this range

defaultNumberRange

public NumberRange defaultNumberRange()

Finds a number range that is enclosed by this range. The range type of the returned range is always CLOSED.

Returns:

a valid number within this range

encloses

public java.lang.String encloses(double number)

Tests whether a given number is enclosed in this range and returns a formatted message if not. If the number is either POS_INF, NEG_INF or NaN, it is never enclosed in the range.

Parameters:

number - the value to check

Returns:

null if number is contained, message if not

encloses

public java.lang.String encloses(double number,
                                 int precision,
                                 java.text.NumberFormat formatter)

Tests whether a given number is enclosed in this range and returns a formatted message if not. This version also takes the given precision into account and rounds the number before checking. If the number is either POS_INF, NEG_INF or NaN, it is never enclosed in the range.

Parameters:

number - the value to check

precision - the number of digits right to the decimal point to take into account for checking

formatter - a formatter for number in the possible error message, can be null

Returns:

null if number is contained, message if not

Throws:

java.lang.IllegalArgumentException - if if (precision < 0)

encloses

public java.lang.String encloses(NumberRange numberRange)

Tests whether a given range is completely enclosed within this range and returns a formatted message if not. A range cannot be enclosed, if one of its bounds is POS_INF or NEG_INF.

Parameters:

numberRange - the range to check

Returns:

null if numberRange is contained, message if not

equals

public boolean equals(java.lang.Object o)

Provides logical equals check.

Overrides:

equals in class java.lang.Object

Parameters:

o - another range to compare with

Returns:

true if lower bound, upper bound and range type are all equal

formattedString

public java.lang.String formattedString(java.text.NumberFormat formatter)

Gets a string representation of this range with a special formatter. If formatter == null, this is identical to toString.

Parameters:

formatter - a number formatter for the bounds, can be null

Returns:

a string in mathematical notation

lowerBound

public double lowerBound()

Gets the lower bound for this range.

Returns:

lower bound

type

public NumberRangeTypes type()

Gets the interval type for this range.

Returns:

range type

upperBound

public double upperBound()

Gets the upper bound for this range.

Returns:

upper bound

hashCode

public int hashCode()

Overrides hashCode, because equals was overwritten. The algorithm was taken from (Joshua Bloch, "Effective Java", Item 8).

Overrides:

hashCode in class java.lang.Object

Returns:

the hash code

toString

public java.lang.String toString()

Gets string representation of this range.

Overrides:

toString in class java.lang.Object

Returns:

a string in mathematical notation

valueOf

public static NumberRange valueOf(java.lang.String exp)

Static initialized that creates a NumberRange from a string representation. Valid expressions are:

• [1,100]
• (-Infinity,100.3]
• (-Infinity,+Infinity)
• (-12E-2,23]
• [100,100]

Parameters:

exp - string containing a valid representation for a number range

Returns:

a number range instance created from exp

Throws:

java.lang.IllegalArgumentException - if exp could not be parsed to a valid number range

See Also:

NumberRange(double lowerBoundNew,double upperBoundNew,NumberRangeTypes rangeType)