Immutable, arbitrary-precision signed decimal numbers. A BigDecimal consists of an arbitrary precision integer unscaled value and a 32-bit 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.) 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 X3.274-1996 and ANSI X3.274-1996/AM 1-2000 (section 7.4). Unlike those standards, BigDecimal includes many rounding modes, which were mandatory for division in BigDecimal releases prior to 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 100×101. 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

OperationPreferred Scale of Result
Addmax(addend.scale(), augend.scale())
Subtractmax(minuend.scale(), subtrahend.scale())
Multiplymultiplier.scale() + multiplicand.scale()
Dividedividend.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 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 high-order 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 can occasionally differ from the rounded mathematical result by more than one unit in the last place, one .

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, pseudo-code is used throughout the descriptions of BigDecimal methods. The pseudo-code expression (i + j) is shorthand for "a BigDecimal whose value is that of the BigDecimal i added to that of the BigDecimal j." The pseudo-code expression (i == j) is shorthand for "true if and only if the BigDecimal i represents the same value as the BigDecimal j." Other pseudo-code 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 , java.util.SortedMap or java.util.SortedSet for more information.

All methods and constructors for this class throw NullPointerException when passed a null object reference for any input parameter.

@author
Josh Bloch
@author
Mike Cowlishaw
@author
Joseph D. Darcy
See Also
Translates a character array representation of a BigDecimal into a BigDecimal, accepting the same sequence of characters as the constructor, while allowing a sub-array 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
Translates a character array representation of a BigDecimal into a BigDecimal, accepting the same sequence of characters as the constructor, while allowing a sub-array 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
Translates a character array representation of a BigDecimal into a BigDecimal, accepting the same sequence of characters as the 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
Translates a character array representation of a BigDecimal into a BigDecimal, accepting the same sequence of characters as the 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
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:
Signopt Significand Exponentopt

Sign:
+
-

Significand:
IntegerPart . FractionPartopt
. FractionPart
IntegerPart

IntegerPart:
Digits

FractionPart:
Digits

Exponent:
ExponentIndicator SignedInteger

ExponentIndicator:
e
E

SignedInteger:
Signopt Digits

Digits:
Digit
Digits Digit

Digit:
any character for which Character#isDigit 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 character-to-digit mapping is provided by java.lang.Character#digit 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]
"-1.23E-12"    [-123,14]
"1234.5E-4"    [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 and Double#toString . 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 constructor.

Parameters
 val String representation of BigDecimal.
Throws
 NumberFormatException if val is not a valid representation of a BigDecimal.
Translates the string representation of a BigDecimal into a BigDecimal, accepting the same strings as the 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
Translates a double into a BigDecimal which is the exact decimal representation of the double's binary floating-point value. The scale of the returned BigDecimal is the smallest value such that (10scale × val) is an integer.

Notes:

1. 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.
2. 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 be used in preference to this one.
3. 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 method and then using the constructor. To get that result, use the static method.
Parameters
 val double value to be converted to BigDecimal.
Throws
 NumberFormatException if val is infinite or NaN.
Translates a double into a BigDecimal, with rounding according to the context settings. The scale of the BigDecimal is the smallest value such that (10scale × 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 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
Translates a BigInteger into a BigDecimal. The scale of the BigDecimal is zero.
Parameters
 val BigInteger value to be converted to BigDecimal.
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
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.
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
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
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
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
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
The value 1, with a scale of 0.
@since
1.5
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.
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.
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.
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.
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.
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.
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.
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.
The value 10, with a scale of 0.
@since
1.5
The value 0, with a scale of 0.
@since
1.5
Returns a BigDecimal whose value is the absolute value of this BigDecimal, and whose scale is this.scale().
Return
abs(this)
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.
Return
abs(this), rounded as necessary.
Throws
 ArithmeticException if the result is inexact but the rounding mode is UNNECESSARY.
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.
Return
this + augend
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.
Return
this + augend, rounded as necessary.
Throws
 ArithmeticException if the result is inexact but the rounding mode is UNNECESSARY.
@since
1.5
Returns the value of the specified number as a `byte`. This may involve rounding or truncation.
Return
the numeric value represented by this object after conversion to type `byte`.
@since
JDK1.1
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.
Return
this BigDecimal converted to a byte.
Throws
 ArithmeticException if this has a nonzero fractional part, or will not fit in a byte.
@since
1.5
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.
Parameters
 val BigDecimal to which this BigDecimal is to be compared.
Return
-1, 0, or 1 as this BigDecimal is numerically less than, equal to, or greater than val.
Compares this object with the specified object for order. Returns a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.

In the foregoing description, the notation sgn(expression) designates the mathematical signum function, which is defined to return one of -1, 0, or 1 according to whether the value of expression is negative, zero or positive. The implementor must ensure sgn(x.compareTo(y)) == -sgn(y.compareTo(x)) for all x and y. (This implies that x.compareTo(y) must throw an exception iff y.compareTo(x) throws an exception.)

The implementor must also ensure that the relation is transitive: (x.compareTo(y)>0 && y.compareTo(z)>0) implies x.compareTo(z)>0.

Finally, the implementer must ensure that x.compareTo(y)==0 implies that sgn(x.compareTo(z)) == sgn(y.compareTo(z)), for all z.

It is strongly recommended, but not strictly required that (x.compareTo(y)==0) == (x.equals(y)). Generally speaking, any class that implements the Comparable interface and violates this condition should clearly indicate this fact. The recommended language is "Note: this class has a natural ordering that is inconsistent with equals."

Parameters
 o the Object to be compared.
Return
a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object.
Throws
 ClassCastException if the specified object's type prevents it from being compared to this Object.
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 non-terminating decimal expansion) an ArithmeticException is thrown.
Parameters
 divisor value by which this BigDecimal is to be divided.
Return
this / divisor
Throws
 ArithmeticException if the exact quotient does not have a terminating decimal expansion
@since
1.5
@author
Joseph D. Darcy
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 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.
Return
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
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 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.
Return
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
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.
Return
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
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.
Return
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 non-terminating decimal expansion.
@since
1.5
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.
Return
this / divisor
Throws
 ArithmeticException if divisor==0, or roundingMode==RoundingMode.UNNECESSARY and this.scale() is insufficient to represent the result of the division exactly.
Returns a two-element 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.
Return
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
Returns a two-element 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.
Return
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
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.
Return
The integer part of this / divisor.
Throws
 ArithmeticException if divisor==0
@since
1.5
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.
Return
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
@author
Joseph D. Darcy
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.
Return
this BigDecimal converted to a double.
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).
Parameters
 x Object to which this BigDecimal is to be compared.
Return
true if and only if the specified Object is a BigDecimal whose value and scale are equal to this BigDecimal's.
See Also
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.
Return
this BigDecimal converted to a float.
Returns the runtime class of an object. That Class object is the object that is locked by static synchronized methods of the represented class.
Return
The `java.lang.Class` object that represents the runtime class of the object. The result is of type {@code Class} where X is the erasure of the static type of the expression on which `getClass` is called.
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.
Return
hash code for this BigDecimal.
See Also
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 low-order 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.
Return
this BigDecimal converted to an int.
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.
Return
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
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 low-order 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.
Return
this BigDecimal converted to a long.
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.
Return
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
Returns the maximum of this BigDecimal and val.
Parameters
 val value with which the maximum is to be computed.
Return
the BigDecimal whose value is the greater of this BigDecimal and val. If they are equal, as defined by the {@link #compareTo(BigDecimal) compareTo} method, this is returned.
See Also
Returns the minimum of this BigDecimal and val.
Parameters
 val value with which the minimum is to be computed.
Return
the BigDecimal whose value is the lesser of this BigDecimal and val. If they are equal, as defined by the {@link #compareTo(BigDecimal) compareTo} method, this is returned.
See Also
Returns a BigDecimal which is equivalent to this one with the decimal point moved n places to the left. If n is non-negative, 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.
Return
a BigDecimal which is equivalent to this one with the decimal point moved n places to the left.
Throws
 ArithmeticException if scale overflows.
Returns a BigDecimal which is equivalent to this one with the decimal point moved n places to the right. If n is non-negative, 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 × 10n) and scale max(this.scale()-n, 0).
Parameters
 n number of places to move the decimal point to the right.
Return
a BigDecimal which is equivalent to this one with the decimal point moved n places to the right.
Throws
 ArithmeticException if scale overflows.
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.
Return
this * multiplicand
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.
Return
this * multiplicand, rounded as necessary.
Throws
 ArithmeticException if the result is inexact but the rounding mode is UNNECESSARY.
@since
1.5
Returns a BigDecimal whose value is (-this), and whose scale is this.scale().
Return
-this.
Returns a BigDecimal whose value is (-this), with rounding according to the context settings.
Parameters
 mc the context to use.
Return
-this, rounded as necessary.
Throws
 ArithmeticException if or the result is inexact but the rounding mode is UNNECESSARY.
@since
1.5
Wakes up a single thread that is waiting on this object's monitor. If any threads are waiting on this object, one of them is chosen to be awakened. The choice is arbitrary and occurs at the discretion of the implementation. A thread waits on an object's monitor by calling one of the `wait` methods.

The awakened thread will not be able to proceed until the current thread relinquishes the lock on this object. The awakened thread will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened thread enjoys no reliable privilege or disadvantage in being the next thread to lock this object.

This method should only be called by a thread that is the owner of this object's monitor. A thread becomes the owner of the object's monitor in one of three ways:

• By executing a synchronized instance method of that object.
• By executing the body of a `synchronized` statement that synchronizes on the object.
• For objects of type `Class,` by executing a synchronized static method of that class.

Only one thread at a time can own an object's monitor.

Throws
 IllegalMonitorStateException if the current thread is not the owner of this object's monitor.
Wakes up all threads that are waiting on this object's monitor. A thread waits on an object's monitor by calling one of the `wait` methods.

The awakened threads will not be able to proceed until the current thread relinquishes the lock on this object. The awakened threads will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened threads enjoy no reliable privilege or disadvantage in being the next thread to lock this object.

This method should only be called by a thread that is the owner of this object's monitor. See the `notify` method for a description of the ways in which a thread can become the owner of a monitor.

Throws
 IllegalMonitorStateException if the current thread is not the owner of this object's monitor.
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 .

Return
this.
@since
1.5
See Also
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 method.

Parameters
 mc the context to use.
Return
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
Returns a BigDecimal whose value is (thisn), 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.
Return
thisn
Throws
 ArithmeticException if n is out of range.
@since
1.5
Returns a BigDecimal whose value is (thisn). The current implementation uses the core algorithm defined in ANSI standard X3.274-1996 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 X3.274-1996 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.
Return
thisn using the ANSI standard X3.274-1996 algorithm
Throws
 ArithmeticException if the result is inexact but the rounding mode is UNNECESSARY, or n is out of range.
@since
1.5
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.

Return
the precision of this BigDecimal.
@since
1.5
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.
Return
this % divisor.
Throws
 ArithmeticException if divisor==0
@since
1.5
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.
Return
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
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 method.

Parameters
 mc the context to use.
Return
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
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.
Return
the scale of this BigDecimal.
Returns a BigDecimal whose numerical value is equal to (this * 10n). The scale of the result is (this.scale() - n).
Throws
 ArithmeticException if the scale would be outside the range of a 32-bit integer.
@since
1.5
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 two-argument 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 setX 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.
Return
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.
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 setX mutate field X. Instead, setScale returns an object with the proper scale; the returned object may or may not be newly allocated.

The new 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.
Return
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
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.
Return
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
Returns the value of the specified number as a `short`. This may involve rounding or truncation.
Return
the numeric value represented by this object after conversion to type `short`.
@since
JDK1.1
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.
Return
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
Returns the signum function of this BigDecimal.
Return
-1, 0, or 1 as the value of this BigDecimal is negative, zero, or positive.
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]
Return
a numerically equal BigDecimal with any trailing zeros removed.
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.
Return
this - subtrahend
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.
Return
this - subtrahend, rounded as necessary.
Throws
 ArithmeticException if the result is inexact but the rounding mode is UNNECESSARY.
@since
1.5
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 method.

Return
this BigDecimal converted to a BigInteger.
Converts this BigDecimal to a BigInteger, checking for lost information. An exception is thrown if this BigDecimal has a nonzero fractional part.
Return
this BigDecimal converted to a BigInteger.
Throws
 ArithmeticException if this has a nonzero fractional part.
@since
1.5
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 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 , 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 . 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.

Return
string representation of this BigDecimal, using engineering notation if an exponent is needed.
@since
1.5
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 , 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.)
Return
a string representation of this BigDecimal without an exponent field.
@since
1.5
See Also
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+(ulength-1), 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]     "1.23E-8"
[-123,12]    "-1.23E-10"
```
Notes:
1. There is a one-to-one 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 constructor, then the original value will be recovered.
2. 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. Locale-sensitive number formatting and parsing is handled by the java.text.NumberFormat class and its subclasses.
3. 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.
4. The digit-to-character mapping provided by Character.forDigit is used.
Return
string representation of this BigDecimal.
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()]```.
Return
the size of an ulp of this
@since
1.5
Returns a BigInteger whose value is the unscaled value of this BigDecimal. (Computes (this * 10this.scale()).)
Return
the unscaled value of this BigDecimal.
@since
1.2
Translates a double into a BigDecimal, using the double's canonical string representation provided by the 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 .

Parameters
 val double to convert to a BigDecimal.
Return
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
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.
Return
a BigDecimal whose value is val.
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.
Return
a BigDecimal whose value is (unscaledVal × 10-scale).
Causes current thread to wait until another thread invokes the method or the method for this object. In other words, this method behaves exactly as if it simply performs the call wait(0).

The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until another thread notifies threads waiting on this object's monitor to wake up either through a call to the `notify` method or the `notifyAll` method. The thread then waits until it can re-obtain ownership of the monitor and resumes execution.

As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:

```     synchronized (obj) {
while (<condition does not hold>)
obj.wait();
... // Perform action appropriate to condition
}
```
This method should only be called by a thread that is the owner of this object's monitor. See the `notify` method for a description of the ways in which a thread can become the owner of a monitor.
Throws
 IllegalMonitorStateException if the current thread is not the owner of the object's monitor. InterruptedException if another thread interrupted the current thread before or while the current thread was waiting for a notification. The interrupted status of the current thread is cleared when this exception is thrown.
Causes current thread to wait until either another thread invokes the method or the method for this object, or a specified amount of time has elapsed.

The current thread must own this object's monitor.

This method causes the current thread (call it T) to place itself in the wait set for this object and then to relinquish any and all synchronization claims on this object. Thread T becomes disabled for thread scheduling purposes and lies dormant until one of four things happens:

• Some other thread invokes the notify method for this object and thread T happens to be arbitrarily chosen as the thread to be awakened.
• Some other thread invokes the notifyAll method for this object.
• Some other thread interrupts thread T.
• The specified amount of real time has elapsed, more or less. If timeout is zero, however, then real time is not taken into consideration and the thread simply waits until notified.
The thread T is then removed from the wait set for this object and re-enabled for thread scheduling. It then competes in the usual manner with other threads for the right to synchronize on the object; once it has gained control of the object, all its synchronization claims on the object are restored to the status quo ante - that is, to the situation as of the time that the wait method was invoked. Thread T then returns from the invocation of the wait method. Thus, on return from the wait method, the synchronization state of the object and of thread T is exactly as it was when the wait method was invoked.

A thread can also wake up without being notified, interrupted, or timing out, a so-called spurious wakeup. While this will rarely occur in practice, applications must guard against it by testing for the condition that should have caused the thread to be awakened, and continuing to wait if the condition is not satisfied. In other words, waits should always occur in loops, like this one:

```     synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout);
... // Perform action appropriate to condition
}
```
(For more information on this topic, see Section 3.2.3 in Doug Lea's "Concurrent Programming in Java (Second Edition)" (Addison-Wesley, 2000), or Item 50 in Joshua Bloch's "Effective Java Programming Language Guide" (Addison-Wesley, 2001).

If the current thread is interrupted by another thread while it is waiting, then an InterruptedException is thrown. This exception is not thrown until the lock status of this object has been restored as described above.

Note that the wait method, as it places the current thread into the wait set for this object, unlocks only this object; any other objects on which the current thread may be synchronized remain locked while the thread waits.

This method should only be called by a thread that is the owner of this object's monitor. See the `notify` method for a description of the ways in which a thread can become the owner of a monitor.

Parameters
 timeout the maximum time to wait in milliseconds.
Throws
 IllegalArgumentException if the value of timeout is negative. IllegalMonitorStateException if the current thread is not the owner of the object's monitor. InterruptedException if another thread interrupted the current thread before or while the current thread was waiting for a notification. The interrupted status of the current thread is cleared when this exception is thrown.
Causes current thread to wait until another thread invokes the method or the method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed.

This method is similar to the `wait` method of one argument, but it allows finer control over the amount of time to wait for a notification before giving up. The amount of real time, measured in nanoseconds, is given by:

` 1000000*timeout+nanos`

In all other respects, this method does the same thing as the method of one argument. In particular, wait(0, 0) means the same thing as wait(0).

The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until either of the following two conditions has occurred:

• Another thread notifies threads waiting on this object's monitor to wake up either through a call to the `notify` method or the `notifyAll` method.
• The timeout period, specified by `timeout` milliseconds plus `nanos` nanoseconds arguments, has elapsed.

The thread then waits until it can re-obtain ownership of the monitor and resumes execution.

As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:

```     synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout, nanos);
... // Perform action appropriate to condition
}
```
This method should only be called by a thread that is the owner of this object's monitor. See the `notify` method for a description of the ways in which a thread can become the owner of a monitor.
Parameters
 timeout the maximum time to wait in milliseconds. nanos additional time, in nanoseconds range 0-999999.
Throws
 IllegalArgumentException if the value of timeout is negative or the value of nanos is not in the range 0-999999. IllegalMonitorStateException if the current thread is not the owner of this object's monitor. InterruptedException if another thread interrupted the current thread before or while the current thread was waiting for a notification. The interrupted status of the current thread is cleared when this exception is thrown.