java.lang

Class Long

public final class Long extends Number implements Comparable<Long>

Instances of class Long represent primitive long values. Additionally, this class provides various helper functions and variables related to longs.

Since: 1.0

UNKNOWN: updated to 1.5

Field Summary
static long	MAX_VALUE The maximum value a `long` can represent is 9223372036854775807 (or 2⁶³ - 1).
static long	MIN_VALUE The minimum value a `long` can represent is -9223372036854775808L (or -2⁶³).
static int	SIZE The number of bits needed to represent a `long`.
static Class<Long>	TYPE The primitive type `long` is represented by this `Class` object.

Constructor Summary
	Long(long value) Create a `Long` object representing the value of the `long` argument.
	Long(String s) Create a `Long` object representing the value of the argument after conversion to a `long`.

Method Summary
static int	bitCount(long x) Return the number of bits set in x.
byte	byteValue() Return the value of this `Long` as a `byte`.
int	compareTo(Long l) Compare two Longs numerically by comparing their `long` values.
static Long	decode(String str) Convert the specified `String` into a `Long`.
double	doubleValue() Return the value of this `Long` as a `double`.
boolean	equals(Object obj) Returns `true` if `obj` is an instance of `Long` and represents the same long value.
float	floatValue() Return the value of this `Long` as a `float`.
static Long	getLong(String nm) Get the specified system property as a `Long`.
static Long	getLong(String nm, long val) Get the specified system property as a `Long`, or use a default `long` value if the property is not found or is not decodable.
static Long	getLong(String nm, Long def) Get the specified system property as a `Long`, or use a default `Long` value if the property is not found or is not decodable.
int	hashCode() Return a hashcode representing this Object.
static long	highestOneBit(long value) Find the highest set bit in value, and return a new value with only that bit set.
int	intValue() Return the value of this `Long` as an `int`.
long	longValue() Return the value of this `Long`.
static long	lowestOneBit(long value) Find the lowest set bit in value, and return a new value with only that bit set.
static int	numberOfLeadingZeros(long value) Return the number of leading zeros in value.
static int	numberOfTrailingZeros(long value) Find the number of trailing zeros in value.
static long	parseLong(String str, int radix) Converts the specified `String` into an `int` using the specified radix (base).
static long	parseLong(String s) Converts the specified `String` into a `long`.
static long	reverse(long val) Reverse the bits in val.
static long	reverseBytes(long val) Reverse the bytes in val.
static long	rotateLeft(long x, int distance) Rotate x to the left by distance bits.
static long	rotateRight(long x, int distance) Rotate x to the right by distance bits.
short	shortValue() Return the value of this `Long` as a `short`.
static int	signum(long x) Return 1 if x is positive, -1 if it is negative, and 0 if it is zero.
static String	toBinaryString(long l) Converts the `long` to a `String` assuming it is unsigned in base 2.
static String	toHexString(long l) Converts the `long` to a `String` assuming it is unsigned in base 16.
static String	toOctalString(long l) Converts the `long` to a `String` assuming it is unsigned in base 8.
static String	toString(long num, int radix) Converts the `long` to a `String` using the specified radix (base).
static String	toString(long num) Converts the `long` to a `String` and assumes a radix of 10.
String	toString() Converts the `Long` value to a `String` and assumes a radix of 10.
static Long	valueOf(String s, int radix) Creates a new `Long` object using the `String` and specified radix (base).
static Long	valueOf(String s) Creates a new `Long` object using the `String`, assuming a radix of 10.
static Long	valueOf(long val) Returns a `Long` object wrapping the value.

Field Detail

MAX_VALUE

public static final long MAX_VALUE

The maximum value a long can represent is 9223372036854775807 (or 2⁶³ - 1).

MIN_VALUE

public static final long MIN_VALUE

The minimum value a long can represent is -9223372036854775808L (or -2⁶³).

SIZE

public static final int SIZE

The number of bits needed to represent a long.

Since: 1.5

TYPE

public static final Class<Long> TYPE

The primitive type long is represented by this Class object.

Since: 1.1

Constructor Detail

Long

public Long(long value)

Create a Long object representing the value of the long argument.

Parameters: value the value to use

Long

public Long(String s)

Create a Long object representing the value of the argument after conversion to a long.

Parameters: s the string to convert

Throws: NumberFormatException if the String does not contain a long

Method Detail

bitCount

public static int bitCount(long x)

Return the number of bits set in x.

Parameters: x value to examine

Since: 1.5

byteValue

public byte byteValue()

Return the value of this Long as a byte.

Returns: the byte value

compareTo

public int compareTo(Long l)

Compare two Longs numerically by comparing their long values. The result is positive if the first is greater, negative if the second is greater, and 0 if the two are equal.

Parameters: l the Long to compare

Returns: the comparison

Since: 1.2

decode

public static Long decode(String str)

Convert the specified String into a Long. The String may represent decimal, hexadecimal, or octal numbers.

The extended BNF grammar is as follows:

 DecodableString:
      ( [ - ] DecimalNumber )
    | ( [ - ] ( 0x | 0X
              | # ) HexDigit { HexDigit } )
    | ( [ - ] 0 { OctalDigit } )
 DecimalNumber:
        DecimalDigit except '0' { DecimalDigit }
 DecimalDigit:
        Character.digit(d, 10) has value 0 to 9
 OctalDigit:
        Character.digit(d, 8) has value 0 to 7
 DecimalDigit:
        Character.digit(d, 16) has value 0 to 15

Finally, the value must be in the range MIN_VALUE to MAX_VALUE, or an exception is thrown. Note that you cannot use a trailing 'l' or 'L', unlike in Java source code.

Parameters: str the String to interpret

Returns: the value of the String as a Long

Throws: NumberFormatException if s cannot be parsed as a long NullPointerException if s is null

Since: 1.2

doubleValue

public double doubleValue()

Return the value of this Long as a double.

Returns: the double value

equals

public boolean equals(Object obj)

Returns true if obj is an instance of Long and represents the same long value.

Parameters: obj the object to compare

Returns: whether these Objects are semantically equal

floatValue

public float floatValue()

Return the value of this Long as a float.

Returns: the float value

getLong

public static Long getLong(String nm)

Get the specified system property as a Long. The decode() method will be used to interpret the value of the property.

Parameters: nm the name of the system property

Returns: the system property as a Long, or null if the property is not found or cannot be decoded

Throws: SecurityException if accessing the system property is forbidden

getLong

public static Long getLong(String nm, long val)

Get the specified system property as a Long, or use a default long value if the property is not found or is not decodable. The decode() method will be used to interpret the value of the property.

Parameters: nm the name of the system property val the default value

Returns: the value of the system property, or the default

Throws: SecurityException if accessing the system property is forbidden

getLong

public static Long getLong(String nm, Long def)

Get the specified system property as a Long, or use a default Long value if the property is not found or is not decodable. The decode() method will be used to interpret the value of the property.

Parameters: nm the name of the system property def the default value

Returns: the value of the system property, or the default

Throws: SecurityException if accessing the system property is forbidden

hashCode

public int hashCode()

Return a hashcode representing this Object. Long's hash code is calculated by (int) (value ^ (value >> 32)).

Returns: this Object's hash code

highestOneBit

public static long highestOneBit(long value)

Find the highest set bit in value, and return a new value with only that bit set.

Parameters: value the value to examine

Since: 1.5

intValue

public int intValue()

Return the value of this Long as an int.

Returns: the int value

longValue

public long longValue()

Return the value of this Long.

Returns: the long value

lowestOneBit

public static long lowestOneBit(long value)

Find the lowest set bit in value, and return a new value with only that bit set.

Parameters: value the value to examine

Since: 1.5

numberOfLeadingZeros

public static int numberOfLeadingZeros(long value)

Return the number of leading zeros in value.

Parameters: value the value to examine

Since: 1.5

numberOfTrailingZeros

public static int numberOfTrailingZeros(long value)

Find the number of trailing zeros in value.

Parameters: value the value to examine

Since: 1.5

parseLong

public static long parseLong(String str, int radix)

Converts the specified String into an int using the specified radix (base). The string must not be null or empty. It may begin with an optional '-', which will negate the answer, provided that there are also valid digits. Each digit is parsed as if by Character.digit(d, radix), and must be in the range 0 to radix - 1. Finally, the result must be within MIN_VALUE to MAX_VALUE, inclusive. Unlike Double.parseDouble, you may not have a leading '+'; and 'l' or 'L' as the last character is only valid in radices 22 or greater, where it is a digit and not a type indicator.

Parameters: str the String to convert radix the radix (base) to use in the conversion

Returns: the String argument converted to long

Throws: NumberFormatException if s cannot be parsed as a long

parseLong

public static long parseLong(String s)

Converts the specified String into a long. This function assumes a radix of 10.

Parameters: s the String to convert

Returns: the int value of s

Throws: NumberFormatException if s cannot be parsed as a long

reverse

public static long reverse(long val)

Reverse the bits in val.

Since: 1.5

reverseBytes

public static long reverseBytes(long val)

Reverse the bytes in val.

Since: 1.5

rotateLeft

public static long rotateLeft(long x, int distance)

Rotate x to the left by distance bits.

Parameters: x the value to rotate distance the number of bits by which to rotate

Since: 1.5

rotateRight

public static long rotateRight(long x, int distance)

Rotate x to the right by distance bits.

Parameters: x the value to rotate distance the number of bits by which to rotate

Since: 1.5

shortValue

public short shortValue()

Return the value of this Long as a short.

Returns: the short value

signum

public static int signum(long x)

Return 1 if x is positive, -1 if it is negative, and 0 if it is zero.

Parameters: x the value to examine

Since: 1.5

toBinaryString

public static String toBinaryString(long l)

Converts the long to a String assuming it is unsigned in base 2.

Parameters: l the long to convert to String

Returns: the String representation of the argument

toHexString

public static String toHexString(long l)

Converts the long to a String assuming it is unsigned in base 16.

Parameters: l the long to convert to String

Returns: the String representation of the argument

toOctalString

public static String toOctalString(long l)

Converts the long to a String assuming it is unsigned in base 8.

Parameters: l the long to convert to String

Returns: the String representation of the argument

toString

public static String toString(long num, int radix)

Converts the long to a String using the specified radix (base). If the radix exceeds Character.MIN_RADIX or Character.MAX_RADIX, 10 is used instead. If the result is negative, the leading character is '-' ('\\u002D'). The remaining characters come from Character.forDigit(digit, radix) ('0'-'9','a'-'z').

Parameters: num the long to convert to String radix the radix (base) to use in the conversion

Returns: the String representation of the argument