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 @link{#highestOneBit(int)} and @link{#numberOfTrailingZeros(int)}) are based on material from Henry S. Warren, Jr.'s Hacker's Delight , (Addison Wesley, 2002).
Field Summary  

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 Summary  

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. 
Method Summary  

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. 
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 an 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 an 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. 
Methods inherited from class java.lang. Object 

clone , finalize , getClass , notify , notifyAll , wait , wait , wait 
Methods inherited from interface java.lang. Comparable 

compareTo 
Field Detail 

public static final long MIN_VALUE
public static final long MAX_VALUE
public static final Class< Long> TYPE
public static final int SIZE
Constructor Detail 

public Long(long value)
public Long(String s) throws NumberFormatException
Method Detail 

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:
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:0123456789abcdefghijklmnopqrstuvwxyz
Long.toString(n, 16).toUpperCase()
public static String toHexString(long i)
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 0s. 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:
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:0123456789abcdef
Long.toHexString(n).toUpperCase()
public static String toOctalString(long i)
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 0s.
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:
These are the characters '\u0030' through '\u0037'.01234567
public static String toBinaryString(long i)
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 0s. 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.
public static String toString(long i)
public static long parseLong(String s, int radix) throws NumberFormatException
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:
Examples:
parseLong("0", 10) returns 0L parseLong("473", 10) returns 473L 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
public static long parseLong(String s) throws NumberFormatException
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.
public static Long valueOf(String s, int radix) throws NumberFormatException
In other words, this method returns a Long object equal to the value of:
new Long(Long.parseLong(s, radix))
public static Long valueOf(String s) throws NumberFormatException
In other words, this method returns a Long object equal to the value of:
new Long(Long.parseLong(s))
public static LongvalueOf (long l)
public static Long decode(String nm) throws NumberFormatException
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) negative 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.
public byte byteValue()
public short shortValue()
public int intValue()
public long longValue()
public float floatValue()
public double doubleValue()
public String toString()
public int hashCode()
(int)(this.longValue()^(this.longValue()>>>32))
public boolean equals(Object obj)
public static Long getLong(String nm)
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)
public static Long getLong(String nm, long val)
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 a Long object when the default value is not needed.Long result = getLong(nm, null); return (result == null) ? new Long(val) : result;
public static Long getLong(String nm, Long val)
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.
public int compareTo(Long anotherLong)
public static longpublic inthighestOneBitcompareTo(long i)(Objecto)
public static long lowestOneBit (long i)
public static int numberOfLeadingZeros (long i)
Note that this method is closely related to the logarithm base 2. For all positive long values x:
public static int numberOfTrailingZeros (long i)
public static int bitCount (long i)
public static long rotateLeft (long i, int distance)
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) .
public static long rotateRight (long i, int distance)
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) .
public static long reverse (long i)
public static int signum (long i)
public static long reverseBytes (long i)