MathContext

public final class MathContext
extends Object implements Serializable

java.lang.Object
   ↳ java.math.MathContext


Immutable objects which encapsulate the context settings which describe certain rules for numerical operators, such as those implemented by the BigDecimal class.

The base-independent settings are:

  1. precision: the number of digits to be used for an operation; results are rounded to this precision
  2. roundingMode: a RoundingMode object which specifies the algorithm to be used for rounding.

Summary

Fields

public static final MathContext DECIMAL128

A MathContext object with a precision setting matching the precision of the IEEE 754-2019 decimal128 format, 34 digits, and a rounding mode of HALF_EVEN.

public static final MathContext DECIMAL32

A MathContext object with a precision setting matching the precision of the IEEE 754-2019 decimal32 format, 7 digits, and a rounding mode of HALF_EVEN.

public static final MathContext DECIMAL64

A MathContext object with a precision setting matching the precision of the IEEE 754-2019 decimal64 format, 16 digits, and a rounding mode of HALF_EVEN.

public static final MathContext UNLIMITED

A MathContext object whose settings have the values required for unlimited precision arithmetic.

Public constructors

MathContext(int setPrecision)

Constructs a new MathContext with the specified precision and the HALF_UP rounding mode.

MathContext(int setPrecision, RoundingMode setRoundingMode)

Constructs a new MathContext with a specified precision and rounding mode.

MathContext(String val)

Constructs a new MathContext from a string.

Public methods

boolean equals(Object x)

Compares this MathContext with the specified Object for equality.

int getPrecision()

Returns the precision setting.

RoundingMode getRoundingMode()

Returns the roundingMode setting.

int hashCode()

Returns the hash code for this MathContext.

String toString()

Returns the string representation of this MathContext.

Inherited methods

Fields

DECIMAL128

Added in API level 1
public static final MathContext DECIMAL128

A MathContext object with a precision setting matching the precision of the IEEE 754-2019 decimal128 format, 34 digits, and a rounding mode of HALF_EVEN. Note the exponent range of decimal64 is not used for rounding.

DECIMAL32

Added in API level 1
public static final MathContext DECIMAL32

A MathContext object with a precision setting matching the precision of the IEEE 754-2019 decimal32 format, 7 digits, and a rounding mode of HALF_EVEN. Note the exponent range of decimal32 is not used for rounding.

DECIMAL64

Added in API level 1
public static final MathContext DECIMAL64

A MathContext object with a precision setting matching the precision of the IEEE 754-2019 decimal64 format, 16 digits, and a rounding mode of HALF_EVEN. Note the exponent range of decimal64 is not used for rounding.

UNLIMITED

Added in API level 1
public static final MathContext UNLIMITED

A MathContext object whose settings have the values required for unlimited precision arithmetic. The values of the settings are: precision=0 roundingMode=HALF_UP

Public constructors

MathContext

Added in API level 1
public MathContext (int setPrecision)

Constructs a new MathContext with the specified precision and the HALF_UP rounding mode.

Parameters
setPrecision int: The non-negative int precision setting.

Throws
IllegalArgumentException if the setPrecision parameter is less than zero.

MathContext

Added in API level 1
public MathContext (int setPrecision, 
                RoundingMode setRoundingMode)

Constructs a new MathContext with a specified precision and rounding mode.

Parameters
setPrecision int: The non-negative int precision setting.

setRoundingMode RoundingMode: The rounding mode to use.

Throws
IllegalArgumentException if the setPrecision parameter is less than zero.
NullPointerException if the rounding mode argument is null

MathContext

Added in API level 1
public MathContext (String val)

Constructs a new MathContext from a string. The string must be in the same format as that produced by the toString() method.

An IllegalArgumentException is thrown if the precision section of the string is out of range (< 0) or the string is not in the format created by the toString() method.

Parameters
val String: The string to be parsed

Throws
IllegalArgumentException if the precision section is out of range or of incorrect format
NullPointerException if the argument is null

Public methods

equals

Added in API level 1
public boolean equals (Object x)

Compares this MathContext with the specified Object for equality.

Parameters
x Object: Object to which this MathContext is to be compared.

Returns
boolean true if and only if the specified Object is a MathContext object which has exactly the same settings as this object

getPrecision

Added in API level 1
public int getPrecision ()

Returns the precision setting. This value is always non-negative.

Returns
int an int which is the value of the precision setting

getRoundingMode

Added in API level 1
public RoundingMode getRoundingMode ()

Returns the roundingMode setting. This will be one of RoundingMode#CEILING, RoundingMode#DOWN, RoundingMode#FLOOR, RoundingMode#HALF_DOWN, RoundingMode#HALF_EVEN, RoundingMode#HALF_UP, RoundingMode#UNNECESSARY, or RoundingMode#UP.

Returns
RoundingMode a RoundingMode object which is the value of the roundingMode setting

hashCode

Added in API level 1
public int hashCode ()

Returns the hash code for this MathContext.

Returns
int hash code for this MathContext

toString

Added in API level 1
public String toString ()

Returns the string representation of this MathContext. The String returned represents the settings of the MathContext object as two space-delimited words (separated by a single space character, '\u0020', and with no leading or trailing white space), as follows:

  1. The string "precision=", immediately followed by the value of the precision setting as a numeric string as if generated by the Integer.toString method.
  2. The string "roundingMode=", immediately followed by the value of the roundingMode setting as a word. This word will be the same as the name of the corresponding public constant in the RoundingMode enum.

For example:

 precision=9 roundingMode=HALF_UP
 
Additional words may be appended to the result of toString in the future if more properties are added to this class.

Returns
String a String representing the context settings