public final class Long
extends Number
implements Comparable<Long>
java.lang.Object  
↳  java.lang.Number  
↳  java.lang.Long 
The Long
class wraps a value of the primitive type long
in an object. An object of type Long
contains a single field whose type is long
.
In addition, this class provides several methods for converting a long
to a String
and a String
to a long
, as well as other constants and methods useful when dealing with a long
.
Implementation note: The implementations of the "bit twiddling" methods (such as highestOneBit
and numberOfTrailingZeros
) are based on material from Henry S. Warren, Jr.'s Hacker's Delight, (Addison Wesley, 2002).
Constants 


int 
BYTES The number of bytes used to represent a 
long 
MAX_VALUE A constant holding the maximum value a 
long 
MIN_VALUE A constant holding the minimum value a 
int 
SIZE The number of bits used to represent a 
Fields 


public static final Class<Long> 
TYPE The 
Public constructors 


Long(long value) Constructs a newly allocated 

Long(String s) Constructs a newly allocated 
Public methods 


static int 
bitCount(long i) Returns the number of onebits in the two's complement binary representation of the specified 
byte 
byteValue() Returns the value of this 
static int 
compare(long x, long y) Compares two 
int 
compareTo(Long anotherLong) Compares two 
static Long 
decode(String nm) Decodes a 
double 
doubleValue() Returns the value of this 
boolean 
equals(Object obj) Compares this object to the specified object. 
float 
floatValue() Returns the value of this 
static Long 
getLong(String nm, Long val) Returns the 
static Long 
getLong(String nm) Determines the 
static Long 
getLong(String nm, long val) Determines the 
int 
hashCode() Returns a hash code for this 
static int 
hashCode(long value) Returns a hash code for a 
static long 
highestOneBit(long i) Returns a 
int 
intValue() Returns the value of this 
long 
longValue() Returns the value of this 
static long 
lowestOneBit(long i) Returns a 
static long 
max(long a, long b) Returns the greater of two 
static long 
min(long a, long b) Returns the smaller of two 
static int 
numberOfLeadingZeros(long i) Returns the number of zero bits preceding the highestorder ("leftmost") onebit in the two's complement binary representation of the specified 
static int 
numberOfTrailingZeros(long i) Returns the number of zero bits following the lowestorder ("rightmost") onebit in the two's complement binary representation of the specified 
static long 
parseLong(String s) Parses the string argument as a signed decimal 
static long 
parseLong(String s, int radix) Parses the string argument as a signed 
static long 
reverse(long i) Returns the value obtained by reversing the order of the bits in the two's complement binary representation of the specified 
static long 
reverseBytes(long i) Returns the value obtained by reversing the order of the bytes in the two's complement representation of the specified 
static long 
rotateLeft(long i, int distance) Returns the value obtained by rotating the two's complement binary representation of the specified 
static long 
rotateRight(long i, int distance) Returns the value obtained by rotating the two's complement binary representation of the specified 
short 
shortValue() Returns the value of this 
static int 
signum(long i) Returns the signum function of the specified 
static long 
sum(long a, long b) Adds two 
static String 
toBinaryString(long i) Returns a string representation of the 
static String 
toHexString(long i) Returns a string representation of the 
static String 
toOctalString(long i) Returns a string representation of the 
static String 
toString(long i, int radix) Returns a string representation of the first argument in the radix specified by the second argument. 
String 
toString() Returns a 
static String 
toString(long i) Returns a 
static Long 
valueOf(String s) Returns a 
static Long 
valueOf(String s, int radix) Returns a 
static Long 
valueOf(long l) Returns a 
Inherited methods 


From class java.lang.Number


From class java.lang.Object


From interface java.lang.Comparable

int BYTES
The number of bytes used to represent a long
value in two's complement binary form.
Constant Value: 8 (0x00000008)
long MAX_VALUE
A constant holding the maximum value a long
can have, 2^{63}1.
Constant Value: 9223372036854775807 (0x7fffffffffffffff)
long MIN_VALUE
A constant holding the minimum value a long
can have, 2^{63}.
Constant Value: 9223372036854775808 (0x8000000000000000)
int SIZE
The number of bits used to represent a long
value in two's complement binary form.
Constant Value: 64 (0x00000040)
Long (long value)
Constructs a newly allocated Long
object that represents the specified long
argument.
Parameters  

value 
long : the value to be represented by the Long object. 
Long (String s)
Constructs a newly allocated Long
object that represents the long
value indicated by the String
parameter. The string is converted to a long
value in exactly the manner used by the parseLong
method for radix 10.
Parameters  

s 
String : the String to be converted to a Long . 
Throws  

NumberFormatException 
if the String does not contain a parsable long . 
See also:
int bitCount (long i)
Returns the number of onebits in the two's complement binary representation of the specified long
value. This function is sometimes referred to as the population count.
Parameters  

i 
long

Returns  

int 
the number of onebits in the two's complement binary representation of the specified long value. 
byte byteValue ()
Returns the value of this Long
as a byte
.
Returns  

byte 
the numeric value represented by this object after conversion to type byte . 
int compare (long x, long y)
Compares two long
values numerically. The value returned is identical to what would be returned by:
Long.valueOf(x).compareTo(Long.valueOf(y))
Parameters  

x 
long : the first long to compare 
y 
long : the second long to compare 
Returns  

int 
the value 0 if x == y ; a value less than 0 if x < y ; and a value greater than 0 if x > y 
int compareTo (Long anotherLong)
Compares two Long
objects numerically.
Parameters  

anotherLong 
Long : the Long to be compared. 
Returns  

int 
the value 0 if this Long is equal to the argument Long ; a value less than 0 if this Long is numerically less than the argument Long ; and a value greater than 0 if this Long is numerically greater than the argument Long (signed comparison). 
Long decode (String nm)
Decodes a String
into a Long
. Accepts decimal, hexadecimal, and octal numbers given by the following grammar:
DecimalNumeral, HexDigits, and OctalDigits are as defined in section 3.10.1 of The Java™ Language Specification, except that underscores are not accepted between digits.
 DecodableString:
 Sign_{opt} DecimalNumeral
 Sign_{opt}
0x
HexDigits Sign_{opt}
0X
HexDigits Sign_{opt}
#
HexDigits Sign_{opt}
0
OctalDigits
 Sign:

+
The sequence of characters following an optional sign and/or radix specifier ("0x
", "0X
", "#
", or leading zero) is parsed as by the Long.parseLong
method with the indicated radix (10, 16, or 8). This sequence of characters must represent a positive value or a NumberFormatException
will be thrown. The result is negated if first character of the specified String
is the minus sign. No whitespace characters are permitted in the String
.
Parameters  

nm 
String : the String to decode. 
Returns  

Long 
a Long object holding the long value represented by nm 
Throws  

NumberFormatException 
if the String does not contain a parsable long . 
See also:
double doubleValue ()
Returns the value of this Long
as a double
.
Returns  

double 
the numeric value represented by this object after conversion to type double . 
boolean equals (Object obj)
Compares this object to the specified object. The result is true
if and only if the argument is not null
and is a Long
object that contains the same long
value as this object.
Parameters  

obj 
Object : the object to compare with. 
Returns  

boolean 
true if the objects are the same; false otherwise. 
float floatValue ()
Returns the value of this Long
as a float
.
Returns  

float 
the numeric value represented by this object after conversion to type float . 
Long getLong (String nm, Long val)
Returns the long
value of the system property with the specified name. The first argument is treated as the name of a system property. System properties are accessible through the getProperty(java.lang.String)
method. The string value of this property is then interpreted as a long
value, as per the Long.decode
method, and a Long
object representing this value is returned.
0x
or the ASCII character #
, not followed by a minus sign, then the rest of it is parsed as a hexadecimal integer exactly as for the method valueOf(java.lang.String, int)
with radix 16. 0
followed by another character, it is parsed as an octal integer exactly as by the method valueOf(java.lang.String, int)
with radix 8. valueOf(java.lang.String, int)
with radix 10. Note that, in every case, neither L
('\u004C'
) nor l
('\u006C'
) is permitted to appear at the end of the property value as a type indicator, as would be permitted in Java programming language source code.
The second argument is the default value. The default value is returned if there is no property of the specified name, if the property does not have the correct numeric format, or if the specified name is empty or null
.
Parameters  

nm 
String : property name. 
val 
Long : default value. 
Returns  

Long 
the Long value of the property. 
Long getLong (String nm)
Determines the long
value of the system property with the specified name.
The first argument is treated as the name of a system property. System properties are accessible through the getProperty(java.lang.String)
method. The string value of this property is then interpreted as a long
value and a Long
object representing this value is returned. Details of possible numeric formats can be found with the definition of getProperty
.
If there is no property with the specified name, if the specified name is empty or null
, or if the property does not have the correct numeric format, then null
is returned.
In other words, this method returns a Long
object equal to the value of:
getLong(nm, null)
Parameters  

nm 
String : property name. 
Returns  

Long 
the Long value of the property. 
Long getLong (String nm, long val)
Determines the long
value of the system property with the specified name.
The first argument is treated as the name of a system property. System properties are accessible through the getProperty(java.lang.String)
method. The string value of this property is then interpreted as a long
value and a Long
object representing this value is returned. Details of possible numeric formats can be found with the definition of getProperty
.
The second argument is the default value. A Long
object that represents the value of the second argument is returned if there is no property of the specified name, if the property does not have the correct numeric format, or if the specified name is empty or null.
In other words, this method returns a Long
object equal to the value of:
getLong(nm, new Long(val))
but in practice it may be implemented in a manner such as:
to avoid the unnecessary allocation of aLong result = getLong(nm, null); return (result == null) ? new Long(val) : result;
Long
object when the default value is not needed.
Parameters  

nm 
String : property name. 
val 
long : default value. 
Returns  

Long 
the Long value of the property. 
int hashCode ()
Returns a hash code for this Long
. The result is the exclusive OR of the two halves of the primitive long
value held by this Long
object. That is, the hashcode is the value of the expression:
(int)(this.longValue()^(this.longValue()>>>32))
Returns  

int 
a hash code value for this object. 
int hashCode (long value)
Returns a hash code for a long
value; compatible with Long.hashCode()
.
Parameters  

value 
long : the value to hash 
Returns  

int 
a hash code value for a long value. 
long highestOneBit (long i)
Returns a long
value with at most a single onebit, in the position of the highestorder ("leftmost") onebit in the specified long
value. Returns zero if the specified value has no onebits in its two's complement binary representation, that is, if it is equal to zero.
Parameters  

i 
long

Returns  

long 
a long value with a single onebit, in the position of the highestorder onebit in the specified value, or zero if the specified value is itself equal to zero. 
int intValue ()
Returns the value of this Long
as an int
.
Returns  

int 
the numeric value represented by this object after conversion to type int . 
long longValue ()
Returns the value of this Long
as a long
value.
Returns  

long 
the numeric value represented by this object after conversion to type long . 
long lowestOneBit (long i)
Returns a long
value with at most a single onebit, in the position of the lowestorder ("rightmost") onebit in the specified long
value. Returns zero if the specified value has no onebits in its two's complement binary representation, that is, if it is equal to zero.
Parameters  

i 
long

Returns  

long 
a long value with a single onebit, in the position of the lowestorder onebit in the specified value, or zero if the specified value is itself equal to zero. 
long max (long a, long b)
Returns the greater of two long
values as if by calling Math.max
.
Parameters  

a 
long : the first operand 
b 
long : the second operand 
Returns  

long 
the greater of a and b 
See also:
long min (long a, long b)
Returns the smaller of two long
values as if by calling Math.min
.
Parameters  

a 
long : the first operand 
b 
long : the second operand 
Returns  

long 
the smaller of a and b 
See also:
int numberOfLeadingZeros (long i)
Returns the number of zero bits preceding the highestorder ("leftmost") onebit in the two's complement binary representation of the specified long
value. Returns 64 if the specified value has no onebits in its two's complement representation, in other words if it is equal to zero.
Note that this method is closely related to the logarithm base 2. For all positive long
values x:
63  numberOfLeadingZeros(x)
64  numberOfLeadingZeros(x  1)
Parameters  

i 
long

Returns  

int 
the number of zero bits preceding the highestorder ("leftmost") onebit in the two's complement binary representation of the specified long value, or 64 if the value is equal to zero. 
int numberOfTrailingZeros (long i)
Returns the number of zero bits following the lowestorder ("rightmost") onebit in the two's complement binary representation of the specified long
value. Returns 64 if the specified value has no onebits in its two's complement representation, in other words if it is equal to zero.
Parameters  

i 
long

Returns  

int 
the number of zero bits following the lowestorder ("rightmost") onebit in the two's complement binary representation of the specified long value, or 64 if the value is equal to zero. 
long parseLong (String s)
Parses the string argument as a signed decimal long
. The characters in the string must all be decimal digits, except that the first character may be an ASCII minus sign ''
(\u002D'
) to indicate a negative value or an ASCII plus sign '+'
('\u002B'
) to indicate a positive value. The resulting long
value is returned, exactly as if the argument and the radix 10
were given as arguments to the parseLong(java.lang.String, int)
method.
Note that neither the character L
('\u004C'
) nor l
('\u006C'
) is permitted to appear at the end of the string as a type indicator, as would be permitted in Java programming language source code.
Parameters  

s 
String : a String containing the long representation to be parsed 
Returns  

long 
the long represented by the argument in decimal. 
Throws  

NumberFormatException 
if the string does not contain a parsable long . 
long parseLong (String s, int radix)
Parses the string argument as a signed long
in the radix specified by the second argument. The characters in the string must all be digits of the specified radix (as determined by whether digit(char, int)
returns a nonnegative value), except that the first character may be an ASCII minus sign ''
('\u002D'
) to indicate a negative value or an ASCII plus sign '+'
('\u002B'
) to indicate a positive value. The resulting long
value is returned.
Note that neither the character L
('\u004C'
) nor l
('\u006C'
) is permitted to appear at the end of the string as a type indicator, as would be permitted in Java programming language source code  except that either L
or l
may appear as a digit for a radix greater than 22.
An exception of type NumberFormatException
is thrown if any of the following situations occurs:
null
or is a string of length zero. radix
is either smaller than MIN_RADIX
or larger than MAX_RADIX
. ''
('\u002d'
) or plus sign '+'
('\u002B'
) provided that the string is longer than length 1. long
. Examples:
parseLong("0", 10) returns 0L parseLong("473", 10) returns 473L parseLong("+42", 10) returns 42L parseLong("0", 10) returns 0L parseLong("FF", 16) returns 255L parseLong("1100110", 2) returns 102L parseLong("99", 8) throws a NumberFormatException parseLong("Hazelnut", 10) throws a NumberFormatException parseLong("Hazelnut", 36) returns 1356099454469L
Parameters  

s 
String : the String containing the long representation to be parsed. 
radix 
int : the radix to be used while parsing s . 
Returns  

long 
the long represented by the string argument in the specified radix. 
Throws  

NumberFormatException 
if the string does not contain a parsable long . 
long reverse (long i)
Returns the value obtained by reversing the order of the bits in the two's complement binary representation of the specified long
value.
Parameters  

i 
long

Returns  

long 
the value obtained by reversing order of the bits in the specified long value. 
long reverseBytes (long i)
Returns the value obtained by reversing the order of the bytes in the two's complement representation of the specified long
value.
Parameters  

i 
long

Returns  

long 
the value obtained by reversing the bytes in the specified long value. 
long rotateLeft (long i, int distance)
Returns the value obtained by rotating the two's complement binary representation of the specified long
value left by the specified number of bits. (Bits shifted out of the left hand, or highorder, side reenter on the right, or loworder.)
Note that left rotation with a negative distance is equivalent to right rotation: rotateLeft(val, distance) == rotateRight(val, distance)
. Note also that rotation by any multiple of 64 is a noop, so all but the last six bits of the rotation distance can be ignored, even if the distance is negative: rotateLeft(val, distance) == rotateLeft(val, distance & 0x3F)
.
Parameters  

i 
long

distance 
int

Returns  

long 
the value obtained by rotating the two's complement binary representation of the specified long value left by the specified number of bits. 
long rotateRight (long i, int distance)
Returns the value obtained by rotating the two's complement binary representation of the specified long
value right by the specified number of bits. (Bits shifted out of the right hand, or loworder, side reenter on the left, or highorder.)
Note that right rotation with a negative distance is equivalent to left rotation: rotateRight(val, distance) == rotateLeft(val, distance)
. Note also that rotation by any multiple of 64 is a noop, so all but the last six bits of the rotation distance can be ignored, even if the distance is negative: rotateRight(val, distance) == rotateRight(val, distance & 0x3F)
.
Parameters  

i 
long

distance 
int

Returns  

long 
the value obtained by rotating the two's complement binary representation of the specified long value right by the specified number of bits. 
short shortValue ()
Returns the value of this Long
as a short
.
Returns  

short 
the numeric value represented by this object after conversion to type short . 
int signum (long i)
Returns the signum function of the specified long
value. (The return value is 1 if the specified value is negative; 0 if the specified value is zero; and 1 if the specified value is positive.)
Parameters  

i 
long

Returns  

int 
the signum function of the specified long value. 
long sum (long a, long b)
Adds two long
values together as per the + operator.
Parameters  

a 
long : the first operand 
b 
long : the second operand 
Returns  

long 
the sum of a and b 
See also:
String toBinaryString (long i)
Returns a string representation of the long
argument as an unsigned integer in base 2.
The unsigned long
value is the argument plus 2^{64} if the argument is negative; otherwise, it is equal to the argument. This value is converted to a string of ASCII digits in binary (base 2) with no extra leading 0
s. If the unsigned magnitude is zero, it is represented by a single zero character '0'
('\u0030'
); otherwise, the first character of the representation of the unsigned magnitude will not be the zero character. The characters '0'
('\u0030'
) and '1'
('\u0031'
) are used as binary digits.
Parameters  

i 
long : a long to be converted to a string. 
Returns  

String 
the string representation of the unsigned long value represented by the argument in binary (base 2). 
String toHexString (long i)
Returns a string representation of the long
argument as an unsigned integer in base 16.
The unsigned long
value is the argument plus 2^{64} if the argument is negative; otherwise, it is equal to the argument. This value is converted to a string of ASCII digits in hexadecimal (base 16) with no extra leading 0
s. If the unsigned magnitude is zero, it is represented by a single zero character '0'
('\u0030'
); otherwise, the first character of the representation of the unsigned magnitude will not be the zero character. The following characters are used as hexadecimal digits:
0123456789abcdef
These are the characters
'\u0030'
through
'\u0039'
and
'\u0061'
through
'\u0066'
. If uppercase letters are desired, the
toUpperCase()
method may be called on the result:
Long.toHexString(n).toUpperCase()
Parameters  

i 
long : a long to be converted to a string. 
Returns  

String 
the string representation of the unsigned long value represented by the argument in hexadecimal (base 16). 
String toOctalString (long i)
Returns a string representation of the long
argument as an unsigned integer in base 8.
The unsigned long
value is the argument plus 2^{64} if the argument is negative; otherwise, it is equal to the argument. This value is converted to a string of ASCII digits in octal (base 8) with no extra leading 0
s.
If the unsigned magnitude is zero, it is represented by a single zero character '0'
('\u0030'
); otherwise, the first character of the representation of the unsigned magnitude will not be the zero character. The following characters are used as octal digits:
01234567
These are the characters
'\u0030'
through
'\u0037'
.
Parameters  

i 
long : a long to be converted to a string. 
Returns  

String 
the string representation of the unsigned long value represented by the argument in octal (base 8). 
String toString (long i, int radix)
Returns a string representation of the first argument in the radix specified by the second argument.
If the radix is smaller than Character.MIN_RADIX
or larger than Character.MAX_RADIX
, then the radix 10
is used instead.
If the first argument is negative, the first element of the result is the ASCII minus sign ''
('\u002d'
). If the first argument is not negative, no sign character appears in the result.
The remaining characters of the result represent the magnitude of the first argument. If the magnitude is zero, it is represented by a single zero character '0'
('\u0030'
); otherwise, the first character of the representation of the magnitude will not be the zero character. The following ASCII characters are used as digits:
0123456789abcdefghijklmnopqrstuvwxyz
These are
'\u0030'
through
'\u0039'
and
'\u0061'
through
'\u007a'
. If
radix
is
N, then the first
N of these characters are used as radix
N digits in the order shown. Thus, the digits for hexadecimal (radix 16) are
0123456789abcdef
. If uppercase letters are desired, the
toUpperCase()
method may be called on the result:
Long.toString(n, 16).toUpperCase()
Parameters  

i 
long : a long to be converted to a string. 
radix 
int : the radix to use in the string representation. 
Returns  

String 
a string representation of the argument in the specified radix. 
String toString ()
Returns a String
object representing this Long
's value. The value is converted to signed decimal representation and returned as a string, exactly as if the long
value were given as an argument to the toString(long)
method.
Returns  

String 
a string representation of the value of this object in base 10. 
String toString (long i)
Returns a String
object representing the specified long
. The argument is converted to signed decimal representation and returned as a string, exactly as if the argument and the radix 10 were given as arguments to the toString(long, int)
method.
Parameters  

i 
long : a long to be converted. 
Returns  

String 
a string representation of the argument in base 10. 
Long valueOf (String s)
Returns a Long
object holding the value of the specified String
. The argument is interpreted as representing a signed decimal long
, exactly as if the argument were given to the parseLong(java.lang.String)
method. The result is a Long
object that represents the integer value specified by the string.
In other words, this method returns a Long
object equal to the value of:
new Long(Long.parseLong(s))
Parameters  

s 
String : the string to be parsed. 
Returns  

Long 
a Long object holding the value represented by the string argument. 
Throws  

NumberFormatException 
If the string cannot be parsed as a long . 
Long valueOf (String s, int radix)
Returns a Long
object holding the value extracted from the specified String
when parsed with the radix given by the second argument. The first argument is interpreted as representing a signed long
in the radix specified by the second argument, exactly as if the arguments were given to the parseLong(java.lang.String, int)
method. The result is a Long
object that represents the long
value specified by the string.
In other words, this method returns a Long
object equal to the value of:
new Long(Long.parseLong(s, radix))
Parameters  

s 
String : the string to be parsed 
radix 
int : the radix to be used in interpreting s 
Returns  

Long 
a Long object holding the value represented by the string argument in the specified radix. 
Throws  

NumberFormatException 
If the String does not contain a parsable long . 
Long valueOf (long l)
Returns a Long
instance representing the specified long
value. If a new Long
instance is not required, this method should generally be used in preference to the constructor Long(long)
, as this method is likely to yield significantly better space and time performance by caching frequently requested values. Note that unlike the corresponding method in the Integer
class, this method is not required to cache values within a particular range.
Parameters  

l 
long : a long value. 
Returns  

Long 
a Long instance representing l . 