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java.math
Class BigDecimal
java.lang.Object
java.lang.Number
java.math.BigDecimal

All Implemented Interfaces:

Serializable
,
Comparable
<
BigDecimal
>

public class BigDecimal
 extends Number
 implements Comparable<BigDecimal>
Immutable, arbitraryprecision signed decimal numbers. A
BigDecimal
consists of an arbitrary precision integer
unscaled value
and a 32bit integer
scale
. If zero or positive, the scale is the number of digits to the right of the decimal point. If negative, the unscaled value of the number is multiplied by ten to the power of the negation of the scale. The value of the number represented by the
BigDecimal
is therefore
(unscaledValue × 10^{
scale}
)
.
The
BigDecimal
class provides operations for arithmetic, scale manipulation, rounding, comparison, hashing, and format conversion. The
toString()
method provides a canonical representation of a
BigDecimal
.
The
BigDecimal
class gives its user complete control over rounding behavior. If no rounding mode is specified and the exact result cannot be represented, an exception is thrown; otherwise, calculations can be carried out to a chosen precision and rounding mode by supplying an appropriate
MathContext
object to the operation. In either case, eight rounding modes are provided for the control of rounding. Using the integer fields in this class (such as
ROUND_HALF_UP
) to represent rounding mode is largely obsolete; the enumeration values of the
RoundingMode
enum
, (such as
RoundingMode.HALF_UP
) should be used instead.
When a
MathContext
object is supplied with a precision setting of 0 (for example,
MathContext.UNLIMITED
), arithmetic operations are exact, as are the arithmetic methods which take no
MathContext
object. (This is the only behavior that was supported in releases prior to
5.)
1.5.)
As a corollary of computing the exact result, the rounding mode setting of a
MathContext
object with a precision setting of 0 is not used and thus irrelevant. In the case of divide, the exact quotient could have an infinitely long decimal expansion; for example, 1 divided by 3. If the quotient has a nonterminating decimal expansion and the operation is specified to return an exact result, an
ArithmeticException
is thrown. Otherwise, the exact result of the division is returned, as done for other operations.
When the precision setting is not 0, the rules of
BigDecimal
arithmetic are broadly compatible with selected modes of operation of the arithmetic defined in ANSI X3.2741996 and ANSI X3.2741996/AM 12000 (section 7.4). Unlike those standards,
BigDecimal
includes many rounding modes, which were mandatory for division in
BigDecimal
releases prior to
5.
1.5.
Any conflicts between these ANSI standards and the
BigDecimal
specification are resolved in favor of
BigDecimal
.
Since the same numerical value can have different representations (with different scales), the rules of arithmetic and rounding must specify both the numerical result and the scale used in the result's representation.
In general the rounding modes and precision setting determine how operations return results with a limited number of digits when the exact result has more digits (perhaps infinitely many in the case of division) than the number of digits returned. First, the total number of digits to return is specified by the
MathContext
's
precision
setting; this determines the result's
precision
. The digit count starts from the leftmost nonzero digit of the exact result. The rounding mode determines how any discarded trailing digits affect the returned result.
For all arithmetic operators , the operation is carried out as though an exact intermediate result were first calculated and then rounded to the number of digits specified by the precision setting (if necessary), using the selected rounding mode. If the exact result is not returned, some digit positions of the exact result are discarded. When rounding increases the magnitude of the returned result, it is possible for a new digit position to be created by a carry propagating to a leading "9" digit. For example, rounding the value 999.9 to three digits rounding up would be numerically equal to one thousand, represented as 100×10^{
1}
. In such cases, the new "1" is the leading digit position of the returned result.
Besides a logical exact result, each arithmetic operation has a preferred scale for representing a result. The preferred scale for each operation is listed in the table below.
Preferred Scales for Results of Arithmetic Operations
Operation 
Preferred Scale of Result 
Add 
max(addend.scale(), augend.scale()) 
Subtract 
max(minuend.scale(), subtrahend.scale()) 
Multiply 
multiplier.scale() + multiplicand.scale() 
Divide 
dividend.scale()  divisor.scale() 
These scales are the ones used by the methods which return exact arithmetic results; except that an exact divide may have to use a larger scale since the exact result may have more digits. For example,
1/32
is
0.03125
.
Before rounding, the scale of the logical exact intermediate result is the preferred scale for that operation. If the exact numerical result cannot be represented in precision digits, rounding selects the set of digits to return and the scale of the result is reduced from the scale of the intermediate result to the least scale which can represent the precision digits actually returned. If the exact result can be represented with at most precision digits, the representation of the result with the scale closest to the preferred scale is returned. In particular, an exactly representable quotient may be represented in fewer than precision digits by removing trailing zeros and decreasing the scale. For example, rounding to three digits using the
floor
rounding mode,
19/100 = 0.19 // integer=19, scale=2
but
21/110 = 0.190 // integer=190, scale=3
Note that for add, subtract, and multiply, the reduction in scale will equal the number of digit positions of the exact result which are discarded. If the rounding causes a carry propagation to create a new highorder digit position, an additional digit of the result is discarded than when no new digit position is created.
Other methods may have slightly different rounding semantics. For example, the result of the
pow
method using the
specified algorithm
can occasionally differ from the rounded mathematical result by more than one unit in the last place, one
ulp
.
Two types of operations are provided for manipulating the scale of a
BigDecimal
: scaling/rounding operations and decimal point motion operations. Scaling/rounding operations (
setScale
and
round
) return a
BigDecimal
whose value is approximately (or exactly) equal to that of the operand, but whose scale or precision is the specified value; that is, they increase or decrease the precision of the stored number with minimal effect on its value. Decimal point motion operations (
movePointLeft
and
movePointRight
) return a
BigDecimal
created from the operand by moving the decimal point a specified distance in the specified direction.
For the sake of brevity and clarity, pseudocode is used throughout the descriptions of
BigDecimal
methods. The pseudocode expression
(i + j)
is shorthand for "a
BigDecimal
whose value is that of the
BigDecimal
i
added to that of the
BigDecimal
j
." The pseudocode expression
(i == j)
is shorthand for "
true
if and only if the
BigDecimal
i
represents the same value as the
BigDecimal
j
." Other pseudocode expressions are interpreted similarly. Square brackets are used to represent the particular
BigInteger
and scale pair defining a
BigDecimal
value; for example [19, 2] is the
BigDecimal
numerically equal to 0.19 having a scale of 2.
Note: care should be exercised if
BigDecimal
objects are used as keys in a
SortedMap
or elements in a
SortedSet
since
BigDecimal
's
natural ordering
is
inconsistent with equals
. See
Comparable
,
SortedMap
or
SortedSet
for more information.
All methods and constructors for this class throw
NullPointerException
when passed a
null
object reference for any input parameter.

See Also:

BigInteger
,
MathContext
,
RoundingMode
,
SortedMap
,
SortedSet
,
Serialized Form
Field Summary

static
BigDecimal

ONE
The value 1, with a scale of 0. 
static int 
ROUND_CEILING
Rounding mode to round towards positive infinity. 
static int 
ROUND_DOWN
Rounding mode to round towards zero. 
static int 
ROUND_FLOOR
Rounding mode to round towards negative infinity. 
static int 
ROUND_HALF_DOWN
Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round down. 
static int 
ROUND_HALF_EVEN
Rounding mode to round towards the "nearest neighbor" unless both neighbors are equidistant, in which case, round towards the even neighbor. 
static int 
ROUND_HALF_UP
Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round up. 
static int 
ROUND_UNNECESSARY
Rounding mode to assert that the requested operation has an exact result, hence no rounding is necessary. 
static int 
ROUND_UP
Rounding mode to round away from zero. 
static
BigDecimal

TEN
The value 10, with a scale of 0. 
static
BigDecimal

ZERO
The value 0, with a scale of 0. 
Constructor Summary

BigDecimal
(
BigInteger
val)
Translates a
BigInteger
into a
BigDecimal
. 
BigDecimal
(
BigInteger
unscaledVal, int scale)
Translates a
BigInteger
unscaled value and an
int
scale into a
BigDecimal
. 
BigDecimal
(
BigInteger
unscaledVal, int scale,
MathContext
mc)
Translates a
BigInteger
unscaled value and an
int
scale into a
BigDecimal
, with rounding according to the context settings. 
BigDecimal
(
BigInteger
val,
MathContext
mc)
Translates a
BigInteger
into a
BigDecimal
rounding according to the context settings. 
BigDecimal
(char[] in)
Translates a character array representation of a
BigDecimal
into a
BigDecimal
, accepting the same sequence of characters as the
BigDecimal(String)
constructor. 
BigDecimal
(char[] in, int offset, int len)
Translates a character array representation of a
BigDecimal
into a
BigDecimal
, accepting the same sequence of characters as the
BigDecimal(String)
constructor, while allowing a subarray to be specified. 
BigDecimal
(char[] in, int offset, int len,
MathContext
mc)
Translates a character array representation of a
BigDecimal
into a
BigDecimal
, accepting the same sequence of characters as the
BigDecimal(String)
constructor, while allowing a subarray to be specified and with rounding according to the context settings. 
BigDecimal
(char[] in,
MathContext
mc)
Translates a character array representation of a
BigDecimal
into a
BigDecimal
, accepting the same sequence of characters as the
BigDecimal(String)
constructor and with rounding according to the context settings. 
BigDecimal
(double val)
Translates a
double
into a
BigDecimal
which is the exact decimal representation of the
double
's binary floatingpoint value. 
BigDecimal
(double val,
MathContext
mc)
Translates a
double
into a
BigDecimal
, with rounding according to the context settings. 
BigDecimal
(int val)
Translates an
int
into a
BigDecimal
. 
BigDecimal
(int val,
MathContext
mc)
Translates an
int
into a
BigDecimal
, with rounding according to the context settings. 
BigDecimal
(long val)
Translates a
long
into a
BigDecimal
. 
BigDecimal
(long val,
MathContext
mc)
Translates a
long
into a
BigDecimal
, with rounding according to the context settings. 
BigDecimal
(
String
val)
Translates the string representation of a
BigDecimal
into a
BigDecimal
. 
BigDecimal
(
String
val,
MathContext
mc)
Translates the string representation of a
BigDecimal
into a
BigDecimal
, accepting the same strings as the
BigDecimal(String)
constructor, with rounding according to the context settings. 
Method Summary

BigDecimal

abs
()
Returns a
BigDecimal
whose value is the absolute value of this
BigDecimal
, and whose scale is
this.scale()
. 
BigDecimal

abs
(
MathContext
mc)
Returns a
BigDecimal
whose value is the absolute value of this
BigDecimal
, with rounding according to the context settings. 
BigDecimal

add
(
BigDecimal
augend)
Returns a
BigDecimal
whose value is
(this + augend)
, and whose scale is
max(this.scale(), augend.scale())
. 
BigDecimal

add
(
BigDecimal
augend,
MathContext
mc)
Returns a
BigDecimal
whose value is
(this + augend)
, with rounding according to the context settings. 
byte 
byteValueExact
()
Converts this
BigDecimal
to a
byte
, checking for lost information. 
int 
compareTo
(
BigDecimal
val)
Compares this
BigDecimal
with the specified
BigDecimal
. 
BigDecimal

divide
(
BigDecimal
divisor)
Returns a
BigDecimal
whose value is
(this / divisor)
, and whose preferred scale is
(this.scale()  divisor.scale())
; if the exact quotient cannot be represented (because it has a nonterminating decimal expansion) an
ArithmeticException
is thrown. 
BigDecimal

divide
(
BigDecimal
divisor, int roundingMode)
Returns a
BigDecimal
whose value is
(this / divisor)
, and whose scale is
this.scale()
. 
BigDecimal

divide
(
BigDecimal
divisor, int scale, int roundingMode)
Returns a
BigDecimal
whose value is
(this / divisor)
, and whose scale is as specified. 
BigDecimal

divide
(
BigDecimal
divisor, int scale,
RoundingMode
roundingMode)
Returns a
BigDecimal
whose value is
(this / divisor)
, and whose scale is as specified. 
BigDecimal

divide
(
BigDecimal
divisor,
MathContext
mc)
Returns a
BigDecimal
whose value is
(this / divisor)
, with rounding according to the context settings. 
BigDecimal

divide
(
BigDecimal
divisor,
RoundingMode
roundingMode)
Returns a
BigDecimal
whose value is
(this / divisor)
, and whose scale is
this.scale()
. 
BigDecimal
[] 
divideAndRemainder
(
BigDecimal
divisor)
Returns a twoelement
BigDecimal
array containing the result of
divideToIntegralValue
followed by the result of
remainder
on the two operands. 
BigDecimal
[] 
divideAndRemainder
(
BigDecimal
divisor,
MathContext
mc)
Returns a twoelement
BigDecimal
array containing the result of
divideToIntegralValue
followed by the result of
remainder
on the two operands calculated with rounding according to the context settings. 
BigDecimal

divideToIntegralValue
(
BigDecimal
divisor)
Returns a
BigDecimal
whose value is the integer part of the quotient
(this / divisor)
rounded down. 
BigDecimal

divideToIntegralValue
(
BigDecimal
divisor,
MathContext
mc)
Returns a
BigDecimal
whose value is the integer part of
(this / divisor)
. 
double 
doubleValue
()
Converts this
BigDecimal
to a
double
. 
boolean 
equals
(
Object
x)
Compares this
BigDecimal
with the specified
Object
for equality. 
float 
floatValue
()
Converts this
BigDecimal
to a
float
. 
int 
hashCode
()
Returns the hash code for this
BigDecimal
. 
int 
intValue
()
Converts this
BigDecimal
to an
int
. 
int 
intValueExact
()
Converts this
BigDecimal
to an
int
, checking for lost information. 
long 
longValue
()
Converts this
BigDecimal
to a
long
. 
long 
longValueExact
()
Converts this
BigDecimal
to a
long
, checking for lost information. 
BigDecimal

max
(
BigDecimal
val)
Returns the maximum of this
BigDecimal
and
val
. 
BigDecimal

min
(
BigDecimal
val)
Returns the minimum of this
BigDecimal
and
val
. 
BigDecimal

movePointLeft
(int n)
Returns a
BigDecimal
which is equivalent to this one with the decimal point moved
n
places to the left. 
BigDecimal

movePointRight
(int n)
Returns a
BigDecimal
which is equivalent to this one with the decimal point moved
n
places to the right. 
BigDecimal

multiply
(
BigDecimal
multiplicand)
Returns a
BigDecimal
whose value is
(this × multiplicand)
, and whose scale is
(this.scale() + multiplicand.scale())
. 
BigDecimal

multiply
(
BigDecimal
multiplicand,
MathContext
mc)
Returns a
BigDecimal
whose value is
(this × multiplicand)
, with rounding according to the context settings. 
BigDecimal

negate
()
Returns a
BigDecimal
whose value is
(this)
, and whose scale is
this.scale()
. 
BigDecimal

negate
(
MathContext
mc)
Returns a
BigDecimal
whose value is
(this)
, with rounding according to the context settings. 
BigDecimal

plus
()
Returns a
BigDecimal
whose value is
(+this)
, and whose scale is
this.scale()
. 
BigDecimal

plus
(
MathContext
mc)
Returns a
BigDecimal
whose value is
(+this)
, with rounding according to the context settings. 
BigDecimal

pow
(int n)
Returns a
BigDecimal
whose value is
(this^{
n}
)
, The power is computed exactly, to unlimited precision. 
BigDecimal

pow
(int n,
MathContext
mc)
Returns a
BigDecimal
whose value is
(this^{
n}
)
. 
int 
precision
()
Returns the
precision
of this
BigDecimal
. 
BigDecimal

remainder
(
BigDecimal
divisor)
Returns a
BigDecimal
whose value is
(this % divisor)
. 
BigDecimal

remainder
(
BigDecimal
divisor,
MathContext
mc)
Returns a
BigDecimal
whose value is
(this % divisor)
, with rounding according to the context settings. 
BigDecimal

round
(
MathContext
mc)
Returns a
BigDecimal
rounded according to the
MathContext
settings. 
int 
scale
()
Returns the
scale
of this
BigDecimal
. 
BigDecimal

scaleByPowerOfTen
(int n)
Returns a BigDecimal whose numerical value is equal to (
this
* 10^{
n}
). 
BigDecimal

setScale
(int newScale)
Returns a
BigDecimal
whose scale is the specified value, and whose value is numerically equal to this
BigDecimal
's. 
BigDecimal

setScale
(int newScale, int roundingMode)
Returns a
BigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this
BigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value. 
BigDecimal

setScale
(int newScale,
RoundingMode
roundingMode)
Returns a
BigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this
BigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value. 
short 
shortValueExact
()
Converts this
BigDecimal
to a
short
, checking for lost information. 
int 
signum
()
Returns the signum function of this
BigDecimal
. 
BigDecimal

stripTrailingZeros
()
Returns a
BigDecimal
which is numerically equal to this one but with any trailing zeros removed from the representation. 
BigDecimal

subtract
(
BigDecimal
subtrahend)
Returns a
BigDecimal
whose value is
(this  subtrahend)
, and whose scale is
max(this.scale(), subtrahend.scale())
. 
BigDecimal

subtract
(
BigDecimal
subtrahend,
MathContext
mc)
Returns a
BigDecimal
whose value is
(this  subtrahend)
, with rounding according to the context settings. 
BigInteger

toBigInteger
()
Converts this
BigDecimal
to a
BigInteger
. 
BigInteger

toBigIntegerExact
()
Converts this
BigDecimal
to a
BigInteger
, checking for lost information. 
String

toEngineeringString
()
Returns a string representation of this
BigDecimal
, using engineering notation if an exponent is needed. 
String

toPlainString
()
Returns a string representation of this
BigDecimal
without an exponent field. 
String

toString
()
Returns the string representation of this
BigDecimal
, using scientific notation if an exponent is needed. 
BigDecimal

ulp
()
Returns the size of an ulp, a unit in the last place, of this
BigDecimal
. 
BigInteger

unscaledValue
()
Returns a
BigInteger
whose value is the
unscaled value
of this
BigDecimal
. 
static
BigDecimal

valueOf
(double val)
Translates a
double
into a
BigDecimal
, using the
double
's canonical string representation provided by the
Double.toString(double)
method. 
static
BigDecimal

valueOf
(long val)
Translates a
long
value into a
BigDecimal
with a scale of zero. 
static
BigDecimal

valueOf
(long unscaledVal, int scale)
Translates a
long
unscaled value and an
int
scale into a
BigDecimal
. 
Methods inherited from class java.lang.
Number

byteValue
,
shortValue

Methods inherited from class java.lang.
Object

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

ZERO
public static final BigDecimal ZERO

The value 0, with a scale of 0.

Since:

1.5
ONE
public static final BigDecimal ONE

The value 1, with a scale of 0.

Since:

1.5
TEN
public static final BigDecimal TEN

The value 10, with a scale of 0.

Since:

1.5
ROUND_UP
public static final int ROUND_UP

Rounding mode to round away from zero. Always increments the digit prior to a nonzero discarded fraction. Note that this rounding mode never decreases the magnitude of the calculated value.

See Also:

Constant Field Values
ROUND_DOWN
public static final int ROUND_DOWN

Rounding mode to round towards zero. Never increments the digit prior to a discarded fraction (i.e., truncates). Note that this rounding mode never increases the magnitude of the calculated value.

See Also:

Constant Field Values
ROUND_CEILING
public static final int ROUND_CEILING

Rounding mode to round towards positive infinity. If the
BigDecimal
is positive, behaves as for
ROUND_UP
; if negative, behaves as for
ROUND_DOWN
. Note that this rounding mode never decreases the calculated value.

See Also:

Constant Field Values
ROUND_FLOOR
public static final int ROUND_FLOOR

Rounding mode to round towards negative infinity. If the
BigDecimal
is positive, behave as for
ROUND_DOWN
; if negative, behave as for
ROUND_UP
. Note that this rounding mode never increases the calculated value.

See Also:

Constant Field Values
ROUND_HALF_UP
public static final int ROUND_HALF_UP

Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round up. Behaves as for
ROUND_UP
if the discarded fraction is >= 0.5; otherwise, behaves as for
ROUND_DOWN
. Note that this is the rounding mode that most of us were taught in grade school.

See Also:

Constant Field Values
ROUND_HALF_DOWN
public static final int ROUND_HALF_DOWN

Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round down. Behaves as for
ROUND_UP
if the discarded fraction is > 0.5; otherwise, behaves as for
ROUND_DOWN
.

See Also:

Constant Field Values
ROUND_HALF_EVEN
public static final int ROUND_HALF_EVEN

Rounding mode to round towards the "nearest neighbor" unless both neighbors are equidistant, in which case, round towards the even neighbor. Behaves as for
ROUND_HALF_UP
if the digit to the left of the discarded fraction is odd; behaves as for
ROUND_HALF_DOWN
if it's even. Note that this is the rounding mode that minimizes cumulative error when applied repeatedly over a sequence of calculations.

See Also:

Constant Field Values
ROUND_UNNECESSARY
public static final int ROUND_UNNECESSARY

Rounding mode to assert that the requested operation has an exact result, hence no rounding is necessary. If this rounding mode is specified on an operation that yields an inexact result, an
ArithmeticException
is thrown.

See Also:

Constant Field Values
BigDecimal
public BigDecimal(char[] in,
int offset,
int len)

Translates a character array representation of a
BigDecimal
into a
BigDecimal
, accepting the same sequence of characters as the
BigDecimal(String)
constructor, while allowing a subarray to be specified.
Note that if the sequence of characters is already available within a character array, using this constructor is faster than converting the
char
array to string and using the
BigDecimal(String)
constructor .

Parameters:

in 
char
array that is the source of characters.

offset  first character in the array to inspect.

len  number of characters to consider.

Throws:

NumberFormatException
 if
in
is not a valid representation of a
BigDecimal
or the defined subarray is not wholly within
in
.

Since:

1.5
BigDecimal
public BigDecimal(char[] in,
int offset,
int len,
MathContext mc)

Translates a character array representation of a
BigDecimal
into a
BigDecimal
, accepting the same sequence of characters as the
BigDecimal(String)
constructor, while allowing a subarray to be specified and with rounding according to the context settings.
Note that if the sequence of characters is already available within a character array, using this constructor is faster than converting the
char
array to string and using the
BigDecimal(String)
constructor .

Parameters:

in 
char
array that is the source of characters.

offset  first character in the array to inspect.

len  number of characters to consider..

mc  the context to use.

Throws:

ArithmeticException
 if the result is inexact but the rounding mode is
UNNECESSARY
.

NumberFormatException
 if
in
is not a valid representation of a
BigDecimal
or the defined subarray is not wholly within
in
.

Since:

1.5
BigDecimal
public BigDecimal(char[] in)

Translates a character array representation of a
BigDecimal
into a
BigDecimal
, accepting the same sequence of characters as the
BigDecimal(String)
constructor.
Note that if the sequence of characters is already available as a character array, using this constructor is faster than converting the
char
array to string and using the
BigDecimal(String)
constructor .

Parameters:

in 
char
array that is the source of characters.

Throws:

NumberFormatException
 if
in
is not a valid representation of a
BigDecimal
.

Since:

1.5
BigDecimal
public BigDecimal(char[] in,
MathContext mc)

Translates a character array representation of a
BigDecimal
into a
BigDecimal
, accepting the same sequence of characters as the
BigDecimal(String)
constructor and with rounding according to the context settings.
Note that if the sequence of characters is already available as a character array, using this constructor is faster than converting the
char
array to string and using the
BigDecimal(String)
constructor .

Parameters:

in 
char
array that is the source of characters.

mc  the context to use.

Throws:

ArithmeticException
 if the result is inexact but the rounding mode is
UNNECESSARY
.

NumberFormatException
 if
in
is not a valid representation of a
BigDecimal
.

Since:

1.5
BigDecimal
public BigDecimal(String val)

Translates the string representation of a
BigDecimal
into a
BigDecimal
. The string representation consists of an optional sign,
'+'
(
'\u002B'
) or
''
(
'\u002D'
), followed by a sequence of zero or more decimal digits ("the integer"), optionally followed by a fraction, optionally followed by an exponent.
The fraction consists of a decimal point followed by zero or more decimal digits. The string must contain at least one digit in either the integer or the fraction. The number formed by the sign, the integer and the fraction is referred to as the
significand
.
The exponent consists of the character
'e'
(
'\u0075'
) or
'E'
(
'\u0045'
) followed by one or more decimal digits. The value of the exponent must lie between 
Integer.MAX_VALUE
(
Integer.MIN_VALUE
+1) and
Integer.MAX_VALUE
, inclusive.
More formally, the strings this constructor accepts are described by the following grammar:

BigDecimalString:

Sign_{
opt}
Significand Exponent_{
opt}

Sign:

+



Significand:

IntegerPart
.
FractionPart_{
opt}

.
FractionPart

IntegerPart

IntegerPart:

Digits

FractionPart:

Digits

Exponent:

ExponentIndicator SignedInteger

ExponentIndicator:

e

E

SignedInteger:

Sign_{
opt}
Digits

Digits:

Digit

Digits Digit

Digit:

any character for which
Character.isDigit(char)
returns
true
, including 0, 1, 2 ...
The scale of the returned
BigDecimal
will be the number of digits in the fraction, or zero if the string contains no decimal point, subject to adjustment for any exponent; if the string contains an exponent, the exponent is subtracted from the scale. The value of the resulting scale must lie between
Integer.MIN_VALUE
and
Integer.MAX_VALUE
, inclusive.
The charactertodigit mapping is provided by
Character.digit(char, int)
set to convert to radix 10. The String may not contain any extraneous characters (whitespace, for example).
Examples:
The value of the returned
BigDecimal
is equal to
significand
× 10^{
exponent
}
. For each string on the left, the resulting representation [
BigInteger
,
scale
] is shown on the right.
"0" [0,0]
"0.00" [0,2]
"123" [123,0]
"123" [123,0]
"1.23E3" [123,1]
"1.23E+3" [123,1]
"12.3E+7" [123,6]
"12.0" [120,1]
"12.3" [123,1]
"0.00123" [123,5]
"1.23E12" [123,14]
"1234.5E4" [12345,5]
"0E+7" [0,7]
"0" [0,0]
Note: For values other than
float
and
double
NaN and ±Infinity, this constructor is compatible with the values returned by
Float.toString(float)
and
Double.toString(double)
. This is generally the preferred way to convert a
float
or
double
into a BigDecimal, as it doesn't suffer from the unpredictability of the
BigDecimal(double)
constructor.

Parameters:

val  String representation of
BigDecimal
.

Throws:

NumberFormatException
 if
val
is not a valid representation of a
BigDecimal
.
BigDecimal
public BigDecimal(String val,
MathContext mc)

Translates the string representation of a
BigDecimal
into a
BigDecimal
, accepting the same strings as the
BigDecimal(String)
constructor, with rounding according to the context settings.

Parameters:

val  string representation of a
BigDecimal
.

mc  the context to use.

Throws:

ArithmeticException
 if the result is inexact but the rounding mode is
UNNECESSARY
.

NumberFormatException
 if
val
is not a valid representation of a BigDecimal.

Since:

1.5
BigDecimal
public BigDecimal(double val)

Translates a
double
into a
BigDecimal
which is the exact decimal representation of the
double
's binary floatingpoint value. The scale of the returned
BigDecimal
is the smallest value such that
(10^{
scale}
× val)
is an integer.
Notes:

The results of this constructor can be somewhat unpredictable. One might assume that writing
new BigDecimal(0.1)
in Java creates a
BigDecimal
which is exactly equal to 0.1 (an unscaled value of 1, with a scale of 1), but it is actually equal to 0.1000000000000000055511151231257827021181583404541015625. This is because 0.1 cannot be represented exactly as a
double
(or, for that matter, as a binary fraction of any finite length). Thus, the value that is being passed
in
to the constructor is not exactly equal to 0.1, appearances notwithstanding.

The
String
constructor, on the other hand, is perfectly predictable: writing
new BigDecimal("0.1")
creates a
BigDecimal
which is
exactly
equal to 0.1, as one would expect. Therefore, it is generally recommended that the
String
constructor
be used in preference to this one.

When a
double
must be used as a source for a
BigDecimal
, note that this constructor provides an exact conversion; it does not give the same result as converting the
double
to a
String
using the
Double.toString(double)
method and then using the
BigDecimal(String)
constructor. To get that result, use the
static
valueOf(double)
method.

Parameters:

val 
double
value to be converted to
BigDecimal
.

Throws:

NumberFormatException
 if
val
is infinite or NaN.
BigDecimal
public BigDecimal(double val,
MathContext mc)

Translates a
double
into a
BigDecimal
, with rounding according to the context settings. The scale of the
BigDecimal
is the smallest value such that
(10^{
scale}
× val)
is an integer.
The results of this constructor can be somewhat unpredictable and its use is generally not recommended; see the notes under the
BigDecimal(double)
constructor.

Parameters:

val 
double
value to be converted to
BigDecimal
.

mc  the context to use.

Throws:

ArithmeticException
 if the result is inexact but the RoundingMode is UNNECESSARY.

NumberFormatException
 if
val
is infinite or NaN.

Since:

1.5
BigDecimal
public BigDecimal(BigInteger val)

Translates a
BigInteger
into a
BigDecimal
. The scale of the
BigDecimal
is zero.

Parameters:

val 
BigInteger
value to be converted to
BigDecimal
.
BigDecimal
public BigDecimal(BigInteger val,
MathContext mc)

Translates a
BigInteger
into a
BigDecimal
rounding according to the context settings. The scale of the
BigDecimal
is zero.

Parameters:

val 
BigInteger
value to be converted to
BigDecimal
.

mc  the context to use.

Throws:

ArithmeticException
 if the result is inexact but the rounding mode is
UNNECESSARY
.

Since:

1.5
BigDecimal
public BigDecimal(BigInteger unscaledVal,
int scale)

Translates a
BigInteger
unscaled value and an
int
scale into a
BigDecimal
. The value of the
BigDecimal
is
(unscaledVal × 10^{
scale}
)
.

Parameters:

unscaledVal  unscaled value of the
BigDecimal
.

scale  scale of the
BigDecimal
.
BigDecimal
public BigDecimal(BigInteger unscaledVal,
int scale,
MathContext mc)

Translates a
BigInteger
unscaled value and an
int
scale into a
BigDecimal
, with rounding according to the context settings. The value of the
BigDecimal
is
(unscaledVal × 10^{
scale}
)
, rounded according to the
precision
and rounding mode settings.

Parameters:

unscaledVal  unscaled value of the
BigDecimal
.

scale  scale of the
BigDecimal
.

mc  the context to use.

Throws:

ArithmeticException
 if the result is inexact but the rounding mode is
UNNECESSARY
.

Since:

1.5
BigDecimal
public BigDecimal(int val)

Translates an
int
into a
BigDecimal
. The scale of the
BigDecimal
is zero.

Parameters:

val 
int
value to be converted to
BigDecimal
.

Since:

1.5
BigDecimal
public BigDecimal(int val,
MathContext mc)

Translates an
int
into a
BigDecimal
, with rounding according to the context settings. The scale of the
BigDecimal
, before any rounding, is zero.

Parameters:

val 
int
value to be converted to
BigDecimal
.

mc  the context to use.

Throws:

ArithmeticException
 if the result is inexact but the rounding mode is
UNNECESSARY
.

Since:

1.5
BigDecimal
public BigDecimal(long val)

Translates a
long
into a
BigDecimal
. The scale of the
BigDecimal
is zero.

Parameters:

val 
long
value to be converted to
BigDecimal
.

Since:

1.5
BigDecimal
public BigDecimal(long val,
MathContext mc)

Translates a
long
into a
BigDecimal
, with rounding according to the context settings. The scale of the
BigDecimal
, before any rounding, is zero.

Parameters:

val 
long
value to be converted to
BigDecimal
.

mc  the context to use.

Throws:

ArithmeticException
 if the result is inexact but the rounding mode is
UNNECESSARY
.

Since:

1.5
valueOf
public static BigDecimal valueOf(long unscaledVal,
int scale)

Translates a
long
unscaled value and an
int
scale into a
BigDecimal
. This "static factory method" is provided in preference to a (
long
,
int
) constructor because it allows for reuse of frequently used
BigDecimal
values..



Parameters:

unscaledVal  unscaled value of the
BigDecimal
.

scale  scale of the
BigDecimal
.

Returns:

a
BigDecimal
whose value is
(unscaledVal × 10^{
scale}
)
.
valueOf
public static BigDecimal valueOf(long val)

Translates a
long
value into a
BigDecimal
with a scale of zero. This "static factory method" is provided in preference to a (
long
) constructor because it allows for reuse of frequently used
BigDecimal
values.



Parameters:

val  value of the
BigDecimal
.

Returns:

a
BigDecimal
whose value is
val
.
valueOf
public static BigDecimal valueOf(double val)

Translates a
double
into a
BigDecimal
, using the
double
's canonical string representation provided by the
Double.toString(double)
method.
Note:
This is generally the preferred way to convert a
double
(or
float
) into a
BigDecimal
, as the value returned is equal to that resulting from constructing a
BigDecimal
from the result of using
Double.toString(double)
.



Parameters:

val 
double
to convert to a
BigDecimal
.

Returns:

a
BigDecimal
whose value is equal to or approximately equal to the value of
val
.

Throws:

NumberFormatException
 if
val
is infinite or NaN.

Since:

1.5
add
public BigDecimal add(BigDecimal augend)

Returns a
BigDecimal
whose value is
(this + augend)
, and whose scale is
max(this.scale(), augend.scale())
.



Parameters:

augend  value to be added to this
BigDecimal
.

Returns:

this + augend
add
public BigDecimal add(BigDecimal augend,
MathContext mc)

Returns a
BigDecimal
whose value is
(this + augend)
, with rounding according to the context settings. If either number is zero and the precision setting is nonzero then the other number, rounded if necessary, is used as the result.



Parameters:

augend  value to be added to this
BigDecimal
.

mc  the context to use.

Returns:

this + augend
, rounded as necessary.

Throws:

ArithmeticException
 if the result is inexact but the rounding mode is
UNNECESSARY
.

Since:

1.5
subtract
public BigDecimal subtract(BigDecimal subtrahend)

Returns a
BigDecimal
whose value is
(this  subtrahend)
, and whose scale is
max(this.scale(), subtrahend.scale())
.



Parameters:

subtrahend  value to be subtracted from this
BigDecimal
.

Returns:

this  subtrahend
subtract
public BigDecimal subtract(BigDecimal subtrahend,
MathContext mc)

Returns a
BigDecimal
whose value is
(this  subtrahend)
, with rounding according to the context settings. If
subtrahend
is zero then this, rounded if necessary, is used as the result. If this is zero then the result is
subtrahend.negate(mc)
.



Parameters:

subtrahend  value to be subtracted from this
BigDecimal
.

mc  the context to use.

Returns:

this  subtrahend
, rounded as necessary.

Throws:

ArithmeticException
 if the result is inexact but the rounding mode is
UNNECESSARY
.

Since:

1.5
multiply
public BigDecimal multiply(BigDecimal multiplicand)

Returns a
BigDecimal
whose value is
(this × multiplicand)
, and whose scale is
(this.scale() + multiplicand.scale())
.



Parameters:

multiplicand  value to be multiplied by this
BigDecimal
.

Returns:

this * multiplicand
multiply
public BigDecimal multiply(BigDecimal multiplicand,
MathContext mc)

Returns a
BigDecimal
whose value is
(this × multiplicand)
, with rounding according to the context settings.



Parameters:

multiplicand  value to be multiplied by this
BigDecimal
.

mc  the context to use.

Returns:

this * multiplicand
, rounded as necessary.

Throws:

ArithmeticException
 if the result is inexact but the rounding mode is
UNNECESSARY
.

Since:

1.5
divide
public BigDecimal divide(BigDecimal divisor,
int scale,
int roundingMode)

Returns a
BigDecimal
whose value is
(this / divisor)
, and whose scale is as specified. If rounding must be performed to generate a result with the specified scale, the specified rounding mode is applied.
The new
divide(BigDecimal, int, RoundingMode)
method should be used in preference to this legacy method.



Parameters:

divisor  value by which this
BigDecimal
is to be divided.

scale  scale of the
BigDecimal
quotient to be returned.

roundingMode  rounding mode to apply.

Returns:

this / divisor

Throws:

ArithmeticException
 if
divisor
is zero,
roundingMode==ROUND_UNNECESSARY
and the specified scale is insufficient to represent the result of the division exactly.

IllegalArgumentException
 if
roundingMode
does not represent a valid rounding mode.

See Also:

ROUND_UP
,
ROUND_DOWN
,
ROUND_CEILING
,
ROUND_FLOOR
,
ROUND_HALF_UP
,
ROUND_HALF_DOWN
,
ROUND_HALF_EVEN
,
ROUND_UNNECESSARY
divide
public BigDecimal divide(BigDecimal divisor,
int scale,
RoundingMode roundingMode)

Returns a
BigDecimal
whose value is
(this / divisor)
, and whose scale is as specified. If rounding must be performed to generate a result with the specified scale, the specified rounding mode is applied.



Parameters:

divisor  value by which this
BigDecimal
is to be divided.

scale  scale of the
BigDecimal
quotient to be returned.

roundingMode  rounding mode to apply.

Returns:

this / divisor

Throws:

ArithmeticException
 if
divisor
is zero,
roundingMode==RoundingMode.UNNECESSARY
and the specified scale is insufficient to represent the result of the division exactly.

Since:

1.5
divide
public BigDecimal divide(BigDecimal divisor,
int roundingMode)

Returns a
BigDecimal
whose value is
(this / divisor)
, and whose scale is
this.scale()
. If rounding must be performed to generate a result with the given scale, the specified rounding mode is applied.
The new
divide(BigDecimal, RoundingMode)
method should be used in preference to this legacy method.



Parameters:

divisor  value by which this
BigDecimal
is to be divided.

roundingMode  rounding mode to apply.

Returns:

this / divisor

Throws:

ArithmeticException
 if
divisor==0
, or
roundingMode==ROUND_UNNECESSARY
and
this.scale()
is insufficient to represent the result of the division exactly.

IllegalArgumentException
 if
roundingMode
does not represent a valid rounding mode.

See Also:

ROUND_UP
,
ROUND_DOWN
,
ROUND_CEILING
,
ROUND_FLOOR
,
ROUND_HALF_UP
,
ROUND_HALF_DOWN
,
ROUND_HALF_EVEN
,
ROUND_UNNECESSARY
divide
public BigDecimal divide(BigDecimal divisor,
RoundingMode roundingMode)

Returns a
BigDecimal
whose value is
(this / divisor)
, and whose scale is
this.scale()
. If rounding must be performed to generate a result with the given scale, the specified rounding mode is applied.



Parameters:

divisor  value by which this
BigDecimal
is to be divided.

roundingMode  rounding mode to apply.

Returns:

this / divisor

Throws:

ArithmeticException
 if
divisor==0
, or
roundingMode==RoundingMode.UNNECESSARY
and
this.scale()
is insufficient to represent the result of the division exactly.
divide
public BigDecimal divide(BigDecimal divisor)

Returns a
BigDecimal
whose value is
(this / divisor)
, and whose preferred scale is
(this.scale()  divisor.scale())
; if the exact quotient cannot be represented (because it has a nonterminating decimal expansion) an
ArithmeticException
is thrown.



Parameters:

divisor  value by which this
BigDecimal
is to be divided.

Returns:

this / divisor

Throws:

ArithmeticException
 if the exact quotient does not have a terminating decimal expansion

Since:

1.5
divide
public BigDecimal divide(BigDecimal divisor,
MathContext mc)

Returns a
BigDecimal
whose value is
(this / divisor)
, with rounding according to the context settings.



Parameters:

divisor  value by which this
BigDecimal
is to be divided.

mc  the context to use.

Returns:

this / divisor
, rounded as necessary.

Throws:

ArithmeticException
 if the result is inexact but the rounding mode is
UNNECESSARY
or
mc.precision == 0
and the quotient has a nonterminating decimal expansion.

Since:

1.5
divideToIntegralValue
public BigDecimal divideToIntegralValue(BigDecimal divisor)

Returns a
BigDecimal
whose value is the integer part of the quotient
(this / divisor)
rounded down. The preferred scale of the result is (this.scale()  divisor.scale()).



Parameters:

divisor  value by which this
BigDecimal
is to be divided.

Returns:

The integer part of
this / divisor
.

Throws:

ArithmeticException
 if
divisor==0

Since:

1.5
divideToIntegralValue
public BigDecimal divideToIntegralValue(BigDecimal divisor,
MathContext mc)

Returns a
BigDecimal
whose value is the integer part of
(this / divisor)
. Since the integer part of the exact quotient does not depend on the rounding mode, the rounding mode does not affect the values returned by this method. The preferred scale of the result is (this.scale()  divisor.scale()). An
ArithmeticException
is thrown if the integer part of the exact quotient needs more than
mc.precision
digits.



Parameters:

divisor  value by which this
BigDecimal
is to be divided.

mc  the context to use.

Returns:

The integer part of
this / divisor
.

Throws:

ArithmeticException
 if
divisor==0

ArithmeticException
 if
mc.precision
> 0 and the result requires a precision of more than
mc.precision
digits.

Since:

1.5
remainder
public BigDecimal remainder(BigDecimal divisor)

Returns a
BigDecimal
whose value is
(this % divisor)
.
The remainder is given by
this.subtract(this.divideToIntegralValue(divisor).multiply(divisor))
. Note that this is not the modulo operation (the result can be negative).



Parameters:

divisor  value by which this
BigDecimal
is to be divided.

Returns:

this % divisor
.

Throws:

ArithmeticException
 if
divisor==0

Since:

1.5
remainder
public BigDecimal remainder(BigDecimal divisor,
MathContext mc)

Returns a
BigDecimal
whose value is
(this % divisor)
, with rounding according to the context settings. The
MathContext
settings affect the implicit divide used to compute the remainder. The remainder computation itself is by definition exact. Therefore, the remainder may contain more than
mc.getPrecision()
digits.
The remainder is given by
this.subtract(this.divideToIntegralValue(divisor, mc).multiply(divisor))
. Note that this is not the modulo operation (the result can be negative).



Parameters:

divisor  value by which this
BigDecimal
is to be divided.

mc  the context to use.

Returns:

this % divisor
, rounded as necessary.

Throws:

ArithmeticException
 if
divisor==0

ArithmeticException
 if the result is inexact but the rounding mode is
UNNECESSARY
, or
mc.precision
> 0 and the result of
this.divideToIntgralValue(divisor)
would require a precision of more than
mc.precision
digits.

Since:

1.5

See Also:

divideToIntegralValue(java.math.BigDecimal, java.math.MathContext)
divideAndRemainder
public BigDecimal[] divideAndRemainder(BigDecimal divisor)

Returns a twoelement
BigDecimal
array containing the result of
divideToIntegralValue
followed by the result of
remainder
on the two operands.
Note that if both the integer quotient and remainder are needed, this method is faster than using the
divideToIntegralValue
and
remainder
methods separately because the division need only be carried out once.



Parameters:

divisor  value by which this
BigDecimal
is to be divided, and the remainder computed.

Returns:

a two element
BigDecimal
array: the quotient (the result of
divideToIntegralValue
) is the initial element and the remainder is the final element.

Throws:

ArithmeticException
 if
divisor==0

Since:

1.5

See Also:

divideToIntegralValue(java.math.BigDecimal, java.math.MathContext)
,
remainder(java.math.BigDecimal, java.math.MathContext)
divideAndRemainder
public BigDecimal[] divideAndRemainder(BigDecimal divisor,
MathContext mc)

Returns a twoelement
BigDecimal
array containing the result of
divideToIntegralValue
followed by the result of
remainder
on the two operands calculated with rounding according to the context settings.
Note that if both the integer quotient and remainder are needed, this method is faster than using the
divideToIntegralValue
and
remainder
methods separately because the division need only be carried out once.



Parameters:

divisor  value by which this
BigDecimal
is to be divided, and the remainder computed.

mc  the context to use.

Returns:

a two element
BigDecimal
array: the quotient (the result of
divideToIntegralValue
) is the initial element and the remainder is the final element.

Throws:

ArithmeticException
 if
divisor==0

ArithmeticException
 if the result is inexact but the rounding mode is
UNNECESSARY
, or
mc.precision
> 0 and the result of
this.divideToIntgralValue(divisor)
would require a precision of more than
mc.precision
digits.

Since:

1.5

See Also:

divideToIntegralValue(java.math.BigDecimal, java.math.MathContext)
,
remainder(java.math.BigDecimal, java.math.MathContext)
pow
public BigDecimal pow(int n)

Returns a
BigDecimal
whose value is
(this^{
n}
)
, The power is computed exactly, to unlimited precision.
The parameter
n
must be in the range 0 through 999999999, inclusive.
ZERO.pow(0)
returns
ONE
. Note that future releases may expand the allowable exponent range of this method.



Parameters:

n  power to raise this
BigDecimal
to.

Returns:

this^{
n}

Throws:

ArithmeticException
 if
n
is out of range.

Since:

1.5
pow
public BigDecimal pow(int n,
MathContext mc)

Returns a
BigDecimal
whose value is
(this^{
n}
)
. The current implementation uses the core algorithm defined in ANSI standard X3.2741996 with rounding according to the context settings. In general, the returned numerical value is within two ulps of the exact numerical value for the chosen precision. Note that future releases may use a different algorithm with a decreased allowable error bound and increased allowable exponent range.
The X3.2741996 algorithm is:

An
ArithmeticException
exception is thrown if

abs(n) > 999999999

mc.precision == 0
and
n < 0

mc.precision > 0
and
n
has more than
mc.precision
decimal digits

if
n
is zero,
ONE
is returned even if
this
is zero, otherwise

if
n
is positive, the result is calculated via the repeated squaring technique into a single accumulator. The individual multiplications with the accumulator use the same math context settings as in
mc
except for a precision increased to
mc.precision + elength + 1
where
elength
is the number of decimal digits in
n
.

if
n
is negative, the result is calculated as if
n
were positive; this value is then divided into one using the working precision specified above.

The final value from either the positive or negative case is then rounded to the destination precision.



Parameters:

n  power to raise this
BigDecimal
to.

mc  the context to use.

Returns:

this^{
n}
using the ANSI standard X3.2741996 algorithm

Throws:

ArithmeticException
 if the result is inexact but the rounding mode is
UNNECESSARY
, or
n
is out of range.

Since:

1.5
abs
public BigDecimal abs()

Returns a
BigDecimal
whose value is the absolute value of this
BigDecimal
, and whose scale is
this.scale()
.



Returns:

abs(this)
abs
public BigDecimal abs(MathContext mc)

Returns a
BigDecimal
whose value is the absolute value of this
BigDecimal
, with rounding according to the context settings.



Parameters:

mc  the context to use.

Returns:

abs(this)
, rounded as necessary.

Throws:

ArithmeticException
 if the result is inexact but the rounding mode is
UNNECESSARY
.
negate
public BigDecimal negate()

Returns a
BigDecimal
whose value is
(this)
, and whose scale is
this.scale()
.



Returns:

this
.
negate
public BigDecimal negate(MathContext mc)

Returns a
BigDecimal
whose value is
(this)
, with rounding according to the context settings.



Parameters:

mc  the context to use.

Returns:

this
, rounded as necessary.

Throws:

ArithmeticException
 if or the result is inexact but the rounding mode is
UNNECESSARY
.

Since:

1.5
plus
public BigDecimal plus()

Returns a
BigDecimal
whose value is
(+this)
, and whose scale is
this.scale()
.
This method, which simply returns this
BigDecimal
is included for symmetry with the unary minus method
negate()
.



Returns:

this
.

Since:

1.5

See Also:

negate()
plus
public BigDecimal plus(MathContext mc)

Returns a
BigDecimal
whose value is
(+this)
, with rounding according to the context settings.
The effect of this method is identical to that of the
round(MathContext)
method.



Parameters:

mc  the context to use.

Returns:

this
, rounded as necessary. A zero result will have a scale of 0.

Throws:

ArithmeticException
 if the result is inexact but the rounding mode is
UNNECESSARY
.

Since:

1.5

See Also:

round(MathContext)
signum
public int signum()

Returns the signum function of this
BigDecimal
.



Returns:

1, 0, or 1 as the value of this
BigDecimal
is negative, zero, or positive.
scale
public int scale()

Returns the
scale
of this
BigDecimal
. If zero or positive, the scale is the number of digits to the right of the decimal point. If negative, the unscaled value of the number is multiplied by ten to the power of the negation of the scale. For example, a scale of
3
means the unscaled value is multiplied by 1000.



Returns:

the scale of this
BigDecimal
.
precision
public int precision()

Returns the
precision
of this
BigDecimal
. (The precision is the number of digits in the unscaled value.)
The precision of a zero value is 1.



Returns:

the precision of this
BigDecimal
.

Since:

1.5
unscaledValue
public BigInteger unscaledValue()

Returns a
BigInteger
whose value is the
unscaled value
of this
BigDecimal
. (Computes
(this * 10^{
this.scale()}
)
.)



Returns:

the unscaled value of this
BigDecimal
.

Since:

1.2
round
public BigDecimal round(MathContext mc)

Returns a
BigDecimal
rounded according to the
MathContext
settings. If the precision setting is 0 then no rounding takes place.
The effect of this method is identical to that of the
plus(MathContext)
method.



Parameters:

mc  the context to use.

Returns:

a
BigDecimal
rounded according to the
MathContext
settings.

Throws:

ArithmeticException
 if the rounding mode is
UNNECESSARY
and the
BigDecimal
operation would require rounding.

Since:

1.5

See Also:

plus(MathContext)
setScale
public BigDecimal setScale(int newScale,
RoundingMode roundingMode)

Returns a
BigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this
BigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value. If the scale is reduced by the operation, the unscaled value must be divided (rather than multiplied), and the value may be changed; in this case, the specified rounding mode is applied to the division.



Parameters:

newScale  scale of the
BigDecimal
value to be returned.

roundingMode  The rounding mode to apply.

Returns:

a
BigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this
BigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value.

Throws:

ArithmeticException
 if
roundingMode==UNNECESSARY
and the specified scaling operation would require rounding.

Since:

1.5

See Also:

RoundingMode
setScale
public BigDecimal setScale(int newScale,
int roundingMode)

Returns a
BigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this
BigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value. If the scale is reduced by the operation, the unscaled value must be divided (rather than multiplied), and the value may be changed; in this case, the specified rounding mode is applied to the division.
Note that since BigDecimal objects are immutable, calls of this method do
not
result in the original object being modified, contrary to the usual convention of having methods named
set
X
mutate field
X
. Instead,
setScale
returns an object with the proper scale; the returned object may or may not be newly allocated.
The new
setScale(int, RoundingMode)
method should be used in preference to this legacy method.



Parameters:

newScale  scale of the
BigDecimal
value to be returned.

roundingMode  The rounding mode to apply.

Returns:

a
BigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this
BigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value.

Throws:

ArithmeticException
 if
roundingMode==ROUND_UNNECESSARY
and the specified scaling operation would require rounding.

IllegalArgumentException
 if
roundingMode
does not represent a valid rounding mode.

See Also:

ROUND_UP
,
ROUND_DOWN
,
ROUND_CEILING
,
ROUND_FLOOR
,
ROUND_HALF_UP
,
ROUND_HALF_DOWN
,
ROUND_HALF_EVEN
,
ROUND_UNNECESSARY
setScale
public BigDecimal setScale(int newScale)

Returns a
BigDecimal
whose scale is the specified value, and whose value is numerically equal to this
BigDecimal
's. Throws an
ArithmeticException
if this is not possible.
This call is typically used to increase the scale, in which case it is guaranteed that there exists a
BigDecimal
of the specified scale and the correct value. The call can also be used to reduce the scale if the caller knows that the
BigDecimal
has sufficiently many zeros at the end of its fractional part (i.e., factors of ten in its integer value) to allow for the rescaling without changing its value.
This method returns the same result as the twoargument versions of
setScale
, but saves the caller the trouble of specifying a rounding mode in cases where it is irrelevant.
Note that since
BigDecimal
objects are immutable, calls of this method do
not
result in the original object being modified, contrary to the usual convention of having methods named
set
X
mutate field
X
. Instead,
setScale
returns an object with the proper scale; the returned object may or may not be newly allocated.



Parameters:

newScale  scale of the
BigDecimal
value to be returned.

Returns:

a
BigDecimal
whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this
BigDecimal
's unscaled value by the appropriate power of ten to maintain its overall value.

Throws:

ArithmeticException
 if the specified scaling operation would require rounding.

See Also:

setScale(int, int)
,
setScale(int, RoundingMode)
movePointLeft
public BigDecimal movePointLeft(int n)

Returns a
BigDecimal
which is equivalent to this one with the decimal point moved
n
places to the left. If
n
is nonnegative, the call merely adds
n
to the scale. If
n
is negative, the call is equivalent to
movePointRight(n)
. The
BigDecimal
returned by this call has value
(this × 10^{
n}
)
and scale
max(this.scale()+n, 0)
.



Parameters:

n  number of places to move the decimal point to the left.

Returns:

a
BigDecimal
which is equivalent to this one with the decimal point moved
n
places to the left.

Throws:

ArithmeticException
 if scale overflows.
movePointRight
public BigDecimal movePointRight(int n)

Returns a
BigDecimal
which is equivalent to this one with the decimal point moved
n
places to the right. If
n
is nonnegative, the call merely subtracts
n
from the scale. If
n
is negative, the call is equivalent to
movePointLeft(n)
. The
BigDecimal
returned by this call has value
(this × 10^{
n}
)
and scale
max(this.scale()n, 0)
.



Parameters:

n  number of places to move the decimal point to the right.

Returns:

a
BigDecimal
which is equivalent to this one with the decimal point moved
n
places to the right.

Throws:

ArithmeticException
 if scale overflows.
scaleByPowerOfTen
public BigDecimal scaleByPowerOfTen(int n)

Returns a BigDecimal whose numerical value is equal to (
this
* 10^{
n}
). The scale of the result is
(this.scale()  n)
.



Throws:

ArithmeticException
 if the scale would be outside the range of a 32bit integer.

Since:

1.5
stripTrailingZeros
public BigDecimal stripTrailingZeros()

Returns a
BigDecimal
which is numerically equal to this one but with any trailing zeros removed from the representation. For example, stripping the trailing zeros from the
BigDecimal
value
600.0
, which has [
BigInteger
,
scale
] components equals to [6000, 1], yields
6E2
with [
BigInteger
,
scale
] components equals to [6, 2]



Returns:

a numerically equal
BigDecimal
with any trailing zeros removed.
compareTo
public int compareTo(BigDecimal val)

Compares this
BigDecimal
with the specified
BigDecimal
. Two
BigDecimal
objects that are equal in value but have a different scale (like 2.0 and 2.00) are considered equal by this method. This method is provided in preference to individual methods for each of the six boolean comparison operators (<, ==, >, >=, !=, <=). The suggested idiom for performing these comparisons is:
(x.compareTo(y)
<
op
>
0)
, where <
op
> is one of the six comparison operators.


Specified by:

compareTo
in interface
Comparable
<
BigDecimal
>


Parameters:

val 
BigDecimal
to which this
BigDecimal
is to be compared.

Returns:

1, 0, or 1 as this
BigDecimal
is numerically less than, equal to, or greater than
val
.
equals
public boolean equals(Object x)

Compares this
BigDecimal
with the specified
Object
for equality. Unlike
compareTo
, this method considers two
BigDecimal
objects equal only if they are equal in value and scale (thus 2.0 is not equal to 2.00 when compared by this method).


Overrides:

equals
in class
Object


Parameters:

x 
Object
to which this
BigDecimal
is to be compared.

Returns:

true
if and only if the specified
Object
is a
BigDecimal
whose value and scale are equal to this
BigDecimal
's.

See Also:

compareTo(java.math.BigDecimal)
,
hashCode()
min
public BigDecimal min(BigDecimal val)

Returns the minimum of this
BigDecimal
and
val
.



Parameters:

val  value with which the minimum is to be computed.

Returns:

the
BigDecimal
whose value is the lesser of this
BigDecimal
and
val
. If they are equal, as defined by the
compareTo
method,
this
is returned.

See Also:

compareTo(java.math.BigDecimal)
max
public BigDecimal max(BigDecimal val)

Returns the maximum of this
BigDecimal
and
val
.



Parameters:

val  value with which the maximum is to be computed.

Returns:

the
BigDecimal
whose value is the greater of this
BigDecimal
and
val
. If they are equal, as defined by the
compareTo
method,
this
is returned.

See Also:

compareTo(java.math.BigDecimal)
hashCode
public int hashCode()

Returns the hash code for this
BigDecimal
. Note that two
BigDecimal
objects that are numerically equal but differ in scale (like 2.0 and 2.00) will generally
not
have the same hash code.


Overrides:

hashCode
in class
Object


Returns:

hash code for this
BigDecimal
.

See Also:

equals(Object)
toString
public String toString()

Returns the string representation of this
BigDecimal
, using scientific notation if an exponent is needed.
A standard canonical string form of the
BigDecimal
is created as though by the following steps: first, the absolute value of the unscaled value of the
BigDecimal
is converted to a string in base ten using the characters
'0'
through
'9'
with no leading zeros (except if its value is zero, in which case a single
'0'
character is used).
Next, an
adjusted exponent
is calculated; this is the negated scale, plus the number of characters in the converted unscaled value, less one. That is,
scale+(ulength1)
, where
ulength
is the length of the absolute value of the unscaled value in decimal digits (its
precision
).
If the scale is greater than or equal to zero and the adjusted exponent is greater than or equal to
6
, the number will be converted to a character form without using exponential notation. In this case, if the scale is zero then no decimal point is added and if the scale is positive a decimal point will be inserted with the scale specifying the number of characters to the right of the decimal point.
'0'
characters are added to the left of the converted unscaled value as necessary. If no character precedes the decimal point after this insertion then a conventional
'0'
character is prefixed.
Otherwise (that is, if the scale is negative, or the adjusted exponent is less than
6
), the number will be converted to a character form using exponential notation. In this case, if the converted
BigInteger
has more than one digit a decimal point is inserted after the first digit. An exponent in character form is then suffixed to the converted unscaled value (perhaps with inserted decimal point); this comprises the letter
'E'
followed immediately by the adjusted exponent converted to a character form. The latter is in base ten, using the characters
'0'
through
'9'
with no leading zeros, and is always prefixed by a sign character
''
(
'\u002D'
) if the adjusted exponent is negative,
'+'
(
'\u002B'
) otherwise).
Finally, the entire string is prefixed by a minus sign character
''
(
'\u002D'
) if the unscaled value is less than zero. No sign character is prefixed if the unscaled value is zero or positive.
Examples:
For each representation [
unscaled value
,
scale
] on the left, the resulting string is shown on the right.
[123,0] "123"
[123,0] "123"
[123,1] "1.23E+3"
[123,3] "1.23E+5"
[123,1] "12.3"
[123,5] "0.00123"
[123,10] "1.23E8"
[123,12] "1.23E10"
Notes:

There is a onetoone mapping between the distinguishable
BigDecimal
values and the result of this conversion. That is, every distinguishable
BigDecimal
value (unscaled value and scale) has a unique string representation as a result of using
toString
. If that string representation is converted back to a
BigDecimal
using the
BigDecimal(String)
constructor, then the original value will be recovered.

The string produced for a given number is always the same; it is not affected by locale. This means that it can be used as a canonical string representation for exchanging decimal data, or as a key for a Hashtable, etc. Localesensitive number formatting and parsing is handled by the
NumberFormat
class and its subclasses.

The
toEngineeringString()
method may be used for presenting numbers with exponents in engineering notation, and the
setScale
method may be used for rounding a
BigDecimal
so it has a known number of digits after the decimal point.

The digittocharacter mapping provided by
Character.forDigit
is used.


Overrides:

toString
in class
Object


Returns:

string representation of this
BigDecimal
.

See Also:

Character.forDigit(int, int)
,
BigDecimal(java.lang.String)
toEngineeringString
public String toEngineeringString()

Returns a string representation of this
BigDecimal
, using engineering notation if an exponent is needed.
Returns a string that represents the
BigDecimal
as described in the
toString()
method, except that if exponential notation is used, the power of ten is adjusted to be a multiple of three (engineering notation) such that the integer part of nonzero values will be in the range 1 through 999. If exponential notation is used for zero values, a decimal point and one or two fractional zero digits are used so that the scale of the zero value is preserved. Note that unlike the output of
toString()
, the output of this method is not guaranteed to recover the same [integer, scale] pair of this
BigDecimal
if the output string is converting back to a
BigDecimal
using the
string constructor
. The result of this method meets the weaker constraint of always producing a numerically equal result from applying the string constructor to the method's output.



Returns:

string representation of this
BigDecimal
, using engineering notation if an exponent is needed.

Since:

1.5
toPlainString
public String toPlainString()

Returns a string representation of this
BigDecimal
without an exponent field. For values with a positive scale, the number of digits to the right of the decimal point is used to indicate scale. For values with a zero or negative scale, the resulting string is generated as if the value were converted to a numerically equal value with zero scale and as if all the trailing zeros of the zero scale value were present in the result. The entire string is prefixed by a minus sign character '' (
'\u002D'
) if the unscaled value is less than zero. No sign character is prefixed if the unscaled value is zero or positive. Note that if the result of this method is passed to the
string constructor
, only the numerical value of this
BigDecimal
will necessarily be recovered; the representation of the new
BigDecimal
may have a different scale. In particular, if this
BigDecimal
has a positive scale, the string resulting from this method will have a scale of zero when processed by the string constructor. (This method behaves analogously to the
toString
method in 1.4 and earlier releases.)



Returns:

a string representation of this
BigDecimal
without an exponent field.

Since:

1.5

See Also:

toString()
,
toEngineeringString()
toBigInteger
public BigInteger toBigInteger()

Converts this
BigDecimal
to a
BigInteger
. This conversion is analogous to a
narrowing primitive conversion
from
double
to
long
as defined in the
Java Language Specification
: any fractional part of this
BigDecimal
will be discarded. Note that this conversion can lose information about the precision of the
BigDecimal
value.
To have an exception thrown if the conversion is inexact (in other words if a nonzero fractional part is discarded), use the
toBigIntegerExact()
method.



Returns:

this
BigDecimal
converted to a
BigInteger
.
toBigIntegerExact
public BigInteger toBigIntegerExact()

Converts this
BigDecimal
to a
BigInteger
, checking for lost information. An exception is thrown if this
BigDecimal
has a nonzero fractional part.



Returns:

this
BigDecimal
converted to a
BigInteger
.

Throws:

ArithmeticException
 if
this
has a nonzero fractional part.

Since:

1.5
longValue
public long longValue()

Converts this
BigDecimal
to a
long
. This conversion is analogous to a
narrowing primitive conversion
from
double
to
short
as defined in the
Java Language Specification
: any fractional part of this
BigDecimal
will be discarded, and if the resulting "
BigInteger
" is too big to fit in a
long
, only the loworder 64 bits are returned. Note that this conversion can lose information about the overall magnitude and precision of this
BigDecimal
value as well as return a result with the opposite sign.


Specified by:

longValue
in class
Number


Returns:

this
BigDecimal
converted to an
long
.
longValueExact
public long longValueExact()

Converts this
BigDecimal
to a
long
, checking for lost information. If this
BigDecimal
has a nonzero fractional part or is out of the possible range for a
long
result then an
ArithmeticException
is thrown.



Returns:

this
BigDecimal
converted to a
long
.

Throws:

ArithmeticException
 if
this
has a nonzero fractional part, or will not fit in a
long
.

Since:

1.5
intValue
public int intValue()

Converts this
BigDecimal
to an
int
. This conversion is analogous to a
narrowing primitive conversion
from
double
to
short
as defined in the
Java Language Specification
: any fractional part of this
BigDecimal
will be discarded, and if the resulting "
BigInteger
" is too big to fit in an
int
, only the loworder 32 bits are returned. Note that this conversion can lose information about the overall magnitude and precision of this
BigDecimal
value as well as return a result with the opposite sign.


Specified by:

intValue
in class
Number


Returns:

this
BigDecimal
converted to an
int
.
intValueExact
public int intValueExact()

Converts this
BigDecimal
to an
int
, checking for lost information. If this
BigDecimal
has a nonzero fractional part or is out of the possible range for an
int
result then an
ArithmeticException
is thrown.



Returns:

this
BigDecimal
converted to an
int
.

Throws:

ArithmeticException
 if
this
has a nonzero fractional part, or will not fit in an
int
.

Since:

1.5
shortValueExact
public short shortValueExact()

Converts this
BigDecimal
to a
short
, checking for lost information. If this
BigDecimal
has a nonzero fractional part or is out of the possible range for a
short
result then an
ArithmeticException
is thrown.



Returns:

this
BigDecimal
converted to a
short
.

Throws:

ArithmeticException
 if
this
has a nonzero fractional part, or will not fit in a
short
.

Since:

1.5
byteValueExact
public byte byteValueExact()

Converts this
BigDecimal
to a
byte
, checking for lost information. If this
BigDecimal
has a nonzero fractional part or is out of the possible range for a
byte
result then an
ArithmeticException
is thrown.



Returns:

this
BigDecimal
converted to an
byte
.

Throws:

ArithmeticException
 if
this
has a nonzero fractional part, or will not fit in a
byte
.

Since:

1.5
floatValue
public float floatValue()

Converts this
BigDecimal
to a
float
. This conversion is similar to the
narrowing primitive conversion
from
double
to
float
defined in the
Java Language Specification
: if this
BigDecimal
has too great a magnitude to represent as a
float
, it will be converted to
Float.NEGATIVE_INFINITY
or
Float.POSITIVE_INFINITY
as appropriate. Note that even when the return value is finite, this conversion can lose information about the precision of the
BigDecimal
value.


Specified by:

floatValue
in class
Number


Returns:

this
BigDecimal
converted to a
float
.
doubleValue
public double doubleValue()

Converts this
BigDecimal
to a
double
. This conversion is similar to the
narrowing primitive conversion
from
double
to
float
as defined in the
Java Language Specification
: if this
BigDecimal
has too great a magnitude represent as a
double
, it will be converted to
Double.NEGATIVE_INFINITY
or
Double.POSITIVE_INFINITY
as appropriate. Note that even when the return value is finite, this conversion can lose information about the precision of the
BigDecimal
value.


Specified by:

doubleValue
in class
Number


Returns:

this
BigDecimal
converted to a
double
.
ulp
public BigDecimal ulp()

Returns the size of an ulp, a unit in the last place, of this
BigDecimal
. An ulp of a nonzero
BigDecimal
value is the positive distance between this value and the
BigDecimal
value next larger in magnitude with the same number of digits. An ulp of a zero value is numerically equal to 1 with the scale of
this
. The result is stored with the same scale as this so the result for zero and nonzero values is equal to [1, this.scale()].



Returns:

the size of an ulp of
this

Since:

1.5