public final class Long extends Number implements Comparable<Long>
long
.
Implementation note: The "bit twiddling" methods in this class use techniques described in Henry S. Warren, Jr.'s Hacker's Delight, (Addison Wesley, 2002) and Sean Anderson's Bit Twiddling Hacks.
Integer
,
Serialized FormModifier and Type | Field and Description |
---|---|
static long |
MAX_VALUE
Constant for the maximum
long value, 263-1. |
static long |
MIN_VALUE
Constant for the minimum
long value, -263. |
static int |
SIZE
Constant for the number of bits needed to represent a
long in
two's complement form. |
static Class<Long> |
TYPE
The
Class object that represents the primitive type long . |
Constructor and Description |
---|
Long(long value)
Constructs a new
Long with the specified primitive long value. |
Long(String string)
Constructs a new
Long from the specified string. |
Modifier and Type | Method and Description |
---|---|
static int |
bitCount(long v)
Counts the number of 1 bits in the specified long value; this is also
referred to as population count.
|
byte |
byteValue()
Returns this object's value as a byte.
|
static int |
compare(long lhs,
long rhs)
Compares two
long values. |
int |
compareTo(Long object)
Compares this object to the specified long object to determine their
relative order.
|
static Long |
decode(String string)
Parses the specified string and returns a
Long instance if the
string can be decoded into a long value. |
double |
doubleValue()
Returns this object's value as a double.
|
boolean |
equals(Object o)
Compares this instance with the specified object and indicates if they
are equal.
|
float |
floatValue()
Returns this object's value as a float.
|
static Long |
getLong(String string)
Returns the
Long value of the system property identified by
string . |
static Long |
getLong(String string,
long defaultValue)
Returns the
Long value of the system property identified by
string . |
static Long |
getLong(String string,
Long defaultValue)
Returns the
Long value of the system property identified by
string . |
int |
hashCode()
Returns an integer hash code for this object.
|
static long |
highestOneBit(long v)
Determines the highest (leftmost) bit of the specified long value that is
1 and returns the bit mask value for that bit.
|
int |
intValue()
Returns this object's value as an int.
|
long |
longValue()
Gets the primitive value of this long.
|
static long |
lowestOneBit(long v)
Determines the lowest (rightmost) bit of the specified long value that is
1 and returns the bit mask value for that bit.
|
static int |
numberOfLeadingZeros(long v)
Determines the number of leading zeros in the specified long value prior
to the
highest one bit . |
static int |
numberOfTrailingZeros(long v)
Determines the number of trailing zeros in the specified long value after
the
lowest one bit . |
static long |
parseLong(String string)
Parses the specified string as a signed decimal long value.
|
static long |
parseLong(String string,
int radix)
Parses the specified string as a signed long value using the specified
radix.
|
static long |
reverse(long v)
Reverses the order of the bits of the specified long value.
|
static long |
reverseBytes(long v)
Reverses the order of the bytes of the specified long value.
|
static long |
rotateLeft(long v,
int distance)
Rotates the bits of the specified long value to the left by the specified
number of bits.
|
static long |
rotateRight(long v,
int distance)
Rotates the bits of the specified long value to the right by the
specified number of bits.
|
short |
shortValue()
Returns this object's value as a short.
|
static int |
signum(long v)
Returns the value of the
signum function for the specified long
value. |
static String |
toBinaryString(long v)
Converts the specified long value into its binary string representation.
|
static String |
toHexString(long v)
Converts the specified long value into its hexadecimal string
representation.
|
static String |
toOctalString(long v)
Converts the specified long value into its octal string representation.
|
String |
toString()
Returns a string containing a concise, human-readable description of this
object.
|
static String |
toString(long n)
Converts the specified long value into its decimal string representation.
|
static String |
toString(long v,
int radix)
Converts the specified signed long value into a string representation based on
the specified radix.
|
static Long |
valueOf(long v)
Returns a
Long instance for the specified long value. |
static Long |
valueOf(String string)
Parses the specified string as a signed decimal long value.
|
static Long |
valueOf(String string,
int radix)
Parses the specified string as a signed long value using the specified
radix.
|
public static final long MAX_VALUE
long
value, 263-1.public static final long MIN_VALUE
long
value, -263.public static final int SIZE
long
in
two's complement form.public Long(long value)
Long
with the specified primitive long value.value
- the primitive long value to store in the new instance.public Long(String string) throws NumberFormatException
Long
from the specified string.string
- the string representation of a long value.NumberFormatException
- if string
cannot be parsed as a long value.parseLong(String)
public byte byteValue()
Number
public int compareTo(Long object)
compareTo
in interface Comparable<Long>
object
- the long object to compare this object to.object
; 0 if the value of this long and the value of
object
are equal; a positive value if the value of this
long is greater than the value of object
.Comparable
public static int compare(long lhs, long rhs)
long
values.public static Long decode(String string) throws NumberFormatException
Long
instance if the
string can be decoded into a long value. The string may be an optional
minus sign "-" followed by a hexadecimal ("0x..." or "#..."), octal
("0..."), or decimal ("...") representation of a long.string
- a string representation of a long value.Long
containing the value represented by string
.NumberFormatException
- if string
cannot be parsed as a long value.public double doubleValue()
Number
doubleValue
in class Number
public boolean equals(Object o)
o
must be an instance of
Long
and have the same long value as this object.equals
in class Object
o
- the object to compare this long with.true
if the specified object is equal to this
Long
; false
otherwise.Object.hashCode()
public float floatValue()
Number
floatValue
in class Number
public static Long getLong(String string)
Long
value of the system property identified by
string
. Returns null
if string
is null
or empty, if the property can not be found or if its value can not be
parsed as a long.string
- the name of the requested system property.Long
or null
.public static Long getLong(String string, long defaultValue)
Long
value of the system property identified by
string
. Returns the specified default value if string
is
null
or empty, if the property can not be found or if its value
can not be parsed as a long.string
- the name of the requested system property.defaultValue
- the default value that is returned if there is no long system
property with the requested name.Long
or the default
value.public static Long getLong(String string, Long defaultValue)
Long
value of the system property identified by
string
. Returns the specified default value if string
is
null
or empty, if the property can not be found or if its value
can not be parsed as a long.string
- the name of the requested system property.defaultValue
- the default value that is returned if there is no long system
property with the requested name.Long
or the default
value.public int hashCode()
Object
Object.equals(java.lang.Object)
returns true
must return
the same hash code value. This means that subclasses of Object
usually override both methods or neither method.
Note that hash values must not change over time unless information used in equals comparisons also changes.
See Writing a correct
hashCode
method
if you intend implementing your own hashCode
method.
hashCode
in class Object
Object.equals(java.lang.Object)
public int intValue()
Number
public long longValue()
public static long parseLong(String string) throws NumberFormatException
string
- the string representation of a long value.string
.NumberFormatException
- if string
cannot be parsed as a long value.public static long parseLong(String string, int radix) throws NumberFormatException
string
- the string representation of a long value.radix
- the radix to use when parsing.string
using
radix
.NumberFormatException
- if string
cannot be parsed as a long value, or
radix < Character.MIN_RADIX ||
radix > Character.MAX_RADIX
.public short shortValue()
Number
shortValue
in class Number
public static String toBinaryString(long v)
v
- the long value to convert.v
.public static String toHexString(long v)
v
- the long value to convert.l
.public static String toOctalString(long v)
v
- the long value to convert.l
.public String toString()
Object
getClass().getName() + '@' + Integer.toHexString(hashCode())
See Writing a useful
toString
method
if you intend implementing your own toString
method.
public static String toString(long n)
n
- the long to convert.l
.public static String toString(long v, int radix)
radix
is not in the interval
defined by Character.MIN_RADIX
and Character.MAX_RADIX
then 10 is used as the base for the conversion.
This method treats its argument as signed. If you want to convert an
unsigned value to one of the common non-decimal bases, you may find
toBinaryString(long)
, #toHexString
, or toOctalString(long)
more convenient.
v
- the signed long to convert.radix
- the base to use for the conversion.v
.public static Long valueOf(String string) throws NumberFormatException
string
- the string representation of a long value.Long
instance containing the long value represented by
string
.NumberFormatException
- if string
cannot be parsed as a long value.parseLong(String)
public static Long valueOf(String string, int radix) throws NumberFormatException
string
- the string representation of a long value.radix
- the radix to use when parsing.Long
instance containing the long value represented by
string
using radix
.NumberFormatException
- if string
cannot be parsed as a long value, or
radix < Character.MIN_RADIX ||
radix > Character.MAX_RADIX
.parseLong(String, int)
public static long highestOneBit(long v)
v
- the long to examine.v
.public static long lowestOneBit(long v)
v
- the long to examine.v
.public static int numberOfLeadingZeros(long v)
highest one bit
.v
- the long to examine.v
.public static int numberOfTrailingZeros(long v)
lowest one bit
.v
- the long to examine.v
.public static int bitCount(long v)
v
- the long to examine.v
.public static long rotateLeft(long v, int distance)
v
- the long value to rotate left.distance
- the number of bits to rotate.public static long rotateRight(long v, int distance)
v
- the long value to rotate right.distance
- the number of bits to rotate.public static long reverseBytes(long v)
v
- the long value for which to reverse the byte order.public static long reverse(long v)
v
- the long value for which to reverse the bit order.public static int signum(long v)
signum
function for the specified long
value.v
- the long value to check.v
is negative, 1 if v
is positive, 0 if
v
is zero.public static Long valueOf(long v)
Long
instance for the specified long value.
If it is not necessary to get a new Long
instance, it is
recommended to use this method instead of the constructor, since it
maintains a cache of instances which may result in better performance.
v
- the long value to store in the instance.Long
instance containing v
.