java.lang
public final class Long extends Number implements Comparable<Long>
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).
Modifier and Type  Field and Description 

static long 
MAX_VALUE
A constant holding the maximum value a
long can
have, 2^{63}1. 
static long 
MIN_VALUE
A constant holding the minimum value a
long can
have, 2^{63}. 
static int 
SIZE
The number of bits used to represent a
long value in two's
complement binary form. 
static Class<Long> 
TYPE
The
Class instance representing the primitive type
long . 
Constructor and Description 

Long(long value)
Constructs a newly allocated
Long object that
represents the specified long argument. 
Long(String s)
Constructs a newly allocated
Long object that
represents the long value indicated by the
String parameter. 
Modifier and Type  Method and Description 

static int 
bitCount(long i)
Returns 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 . 
static int 
compare(long x,
long y)
Compares two
long values numerically. 
int 
compareTo(Long anotherLong)
Compares two
Long objects numerically. 
static Long 
decode(String nm)
Decodes a
String into a Long . 
double 
doubleValue()
Returns the value of this
Long as a
double . 
boolean 
equals(Object obj)
Compares this object to the specified object.

float 
floatValue()
Returns the value of this
Long as a
float . 
static Long 
getLong(String nm)
Determines the
long value of the system property
with the specified name. 
static Long 
getLong(String nm,
long val)
Determines the
long value of the system property
with the specified name. 
static Long 
getLong(String nm,
Long val)
Returns the
long value of the system property with
the specified name. 
int 
hashCode()
Returns a hash code for this
Long . 
static 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. 
int 
intValue()
Returns the value of this
Long as an
int . 
long 
longValue()
Returns the value of this
Long as a
long value. 
static 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. 
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
long value. 
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
long value. 
static long 
parseLong(String s)
Parses the string argument as a signed decimal
long . 
static long 
parseLong(String s,
int radix)
Parses the string argument as a signed
long in the
radix specified by the second argument. 
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
long
value. 
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
long value. 
static 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. 
static 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. 
short 
shortValue()
Returns the value of this
Long as a
short . 
static int 
signum(long i)
Returns the signum function of the specified
long value. 
static String 
toBinaryString(long i)
Returns a string representation of the
long
argument as an unsigned integer in base 2. 
static String 
toHexString(long i)
Returns a string representation of the
long
argument as an unsigned integer in base 16. 
static String 
toOctalString(long i)
Returns a string representation of the
long
argument as an unsigned integer in base 8. 
String 
toString()
Returns a
String object representing this
Long 's value. 
static String 
toString(long i)
Returns a
String object representing the specified
long . 
static String 
toString(long i,
int radix)
Returns a string representation of the first argument in the
radix specified by the second argument.

static Long 
valueOf(long l)
Returns a
Long instance representing the specified
long value. 
static Long 
valueOf(String s)
Returns a
Long object holding the value
of the specified String . 
static 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. 
public static final long MIN_VALUE
long
can
have, 2^{63}.public static final long MAX_VALUE
long
can
have, 2^{63}1.public static final Class<Long> TYPE
Class
instance representing the primitive type
long
.public static final int SIZE
long
value in two's
complement binary form.public Long(long value)
Long
object that
represents the specified long
argument.value
 the value to be represented by the
Long
object.public Long(String s) throws NumberFormatException
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.s
 the String
to be converted to a
Long
.NumberFormatException
 if the String
does not
contain a parsable long
.parseLong(java.lang.String, int)
public static String toString(long i, int radix)
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 radixN digits in the order shown. Thus,
the digits for hexadecimal (radix 16) are
0123456789abcdef
. If uppercase letters are
desired, the String.toUpperCase()
method may
be called on the result:
Long.toString(n, 16).toUpperCase()
i
 a long
to be converted to a string.radix
 the radix to use in the string representation.Character.MAX_RADIX
,
Character.MIN_RADIX
public static String toHexString(long i)
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 String.toUpperCase()
method may be called
on the result:
Long.toHexString(n).toUpperCase()
i
 a long
to be converted to a string.long
value represented by the argument in hexadecimal
(base 16).public static String toOctalString(long i)
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'
.i
 a long
to be converted to a string.long
value represented by the argument in octal (base 8).public static String toBinaryString(long i)
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.
i
 a long
to be converted to a string.long
value represented by the argument in binary (base 2).public static String toString(long i)
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.i
 a long
to be converted.public static long parseLong(String s, int radix) throws NumberFormatException
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 Character.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 Character.MIN_RADIX
or larger than Character.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
s
 the String
containing the
long
representation to be parsed.radix
 the radix to be used while parsing s
.long
represented by the string argument in
the specified radix.NumberFormatException
 if the string does not contain a
parsable long
.public static long parseLong(String s) throws NumberFormatException
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.
s
 a String
containing the long
representation to be parsedlong
represented by the argument in
decimal.NumberFormatException
 if the string does not contain a
parsable long
.public static Long valueOf(String s, int radix) throws NumberFormatException
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))
s
 the string to be parsedradix
 the radix to be used in interpreting s
Long
object holding the value
represented by the string argument in the specified
radix.NumberFormatException
 If the String
does not
contain a parsable long
.public static Long valueOf(String s) throws NumberFormatException
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))
s
 the string to be parsed.Long
object holding the value
represented by the string argument.NumberFormatException
 If the string cannot be parsed
as a long
.public static Long valueOf(long l)
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.l
 a long value.Long
instance representing l
.public static Long decode(String nm) throws NumberFormatException
String
into a Long
.
Accepts decimal, hexadecimal, and octal numbers given by the
following grammar:
DecimalNumeral, HexDigits, and OctalDigits are defined in §3.10.1 of the Java Language Specification.
 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
.
nm
 the String
to decode.Long
object holding the long
value represented by nm
NumberFormatException
 if the String
does not
contain a parsable long
.parseLong(String, int)
public byte byteValue()
Long
as a
byte
.public short shortValue()
Long
as a
short
.shortValue
in class Number
short
.public int intValue()
Long
as an
int
.public long longValue()
Long
as a
long
value.public float floatValue()
Long
as a
float
.floatValue
in class Number
float
.public double doubleValue()
Long
as a
double
.doubleValue
in class Number
double
.public String toString()
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.public int hashCode()
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))
hashCode
in class Object
Object.equals(java.lang.Object)
,
System.identityHashCode(java.lang.Object)
public boolean equals(Object obj)
true
if and only if the argument is not
null
and is a Long
object that
contains the same long
value as this object.equals
in class Object
obj
 the object to compare with.true
if the objects are the same;
false
otherwise.Object.hashCode()
,
HashMap
public static Long getLong(String nm)
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 System.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)
nm
 property name.Long
value of the property.System.getProperty(java.lang.String)
,
System.getProperty(java.lang.String, java.lang.String)
public static Long getLong(String nm, long val)
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 System.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.nm
 property name.val
 default value.Long
value of the property.System.getProperty(java.lang.String)
,
System.getProperty(java.lang.String, java.lang.String)
public static Long getLong(String nm, Long val)
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 System.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
.
nm
 property name.val
 default value.Long
value of the property.System.getProperty(java.lang.String)
,
System.getProperty(java.lang.String, java.lang.String)
,
decode(java.lang.String)
public int compareTo(Long anotherLong)
Long
objects numerically.compareTo
in interface Comparable<Long>
anotherLong
 the Long
to be compared.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).public static int compare(long x, long y)
long
values numerically.
The value returned is identical to what would be returned by:
Long.valueOf(x).compareTo(Long.valueOf(y))
x
 the first long
to comparey
 the second long
to compare0
if x == y
;
a value less than 0
if x < y
; and
a value greater than 0
if x > y
public static long highestOneBit(long i)
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.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.public static long lowestOneBit(long i)
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.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.public static int numberOfLeadingZeros(long i)
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)
long
value, or 64 if the value
is equal to zero.public static int numberOfTrailingZeros(long i)
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.long
value, or 64 if the value is equal
to zero.public static int bitCount(long i)
long
value. This function is
sometimes referred to as the population count.long
value.public static long rotateLeft(long i, int distance)
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)
.
long
value left by the
specified number of bits.public static long rotateRight(long i, int distance)
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)
.
long
value right by the
specified number of bits.public static long reverse(long i)
long
value.long
value.public static int signum(long i)
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.)long
value.public static long reverseBytes(long i)
long
value.long
value. Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developertargeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 1993, 2010, Oracle Corporation. All rights reserved.
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