Class Long
- java.lang.Object
-
- java.lang.Number
-
- java.lang.Long
- All Implemented Interfaces:
-
Serializable
,Comparable<Long>
public final class Long extends Number implements Comparable<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).
- Since:
- 1.0
- See Also:
- Serialized Form
Field Summary
Modifier and Type | Field | Description |
---|---|---|
static int | BYTES | The number of bytes used to represent a |
static long | MAX_VALUE | A constant holding the maximum value a |
static long | MIN_VALUE | A constant holding the minimum value a |
static int | SIZE | The number of bits used to represent a |
static Class<Long> | TYPE | The |
Constructor Summary
Constructor | Description |
---|---|
Long(long value) | Deprecated. It is rarely appropriate to use this constructor. |
Long(String s) | Deprecated. It is rarely appropriate to use this constructor. |
Method Summary
Modifier and Type | Method | Description |
---|---|---|
static int | bitCount(long i) | Returns the number of one-bits 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 int | compareUnsigned(long x,
long y) | Compares two |
static Long | decode(String nm) | Decodes a |
static long | divideUnsigned(long dividend,
long divisor) | Returns the unsigned quotient of dividing the first argument by the second where each argument and the result is interpreted as an unsigned value. |
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) | Determines the |
static Long | getLong(String nm,
long val) | Determines the |
static Long | getLong(String nm,
Long val) | Returns 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 highest-order ("leftmost") one-bit in the two's complement binary representation of the specified |
static int | numberOfTrailingZeros(long i) | Returns the number of zero bits following the lowest-order ("rightmost") one-bit in the two's complement binary representation of the specified |
static long | parseLong(CharSequence s,
int beginIndex,
int endIndex,
int radix) | Parses the |
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 | parseUnsignedLong(CharSequence s,
int beginIndex,
int endIndex,
int radix) | Parses the |
static long | parseUnsignedLong(String s) | Parses the string argument as an unsigned decimal |
static long | parseUnsignedLong(String s,
int radix) | Parses the string argument as an unsigned |
static long | remainderUnsigned(long dividend,
long divisor) | Returns the unsigned remainder from dividing the first argument by the second where each argument and the result is interpreted as an unsigned value. |
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 |
String | toString() | Returns a |
static String | toString(long i) | Returns a |
static String | toString(long i,
int radix) | Returns a string representation of the first argument in the radix specified by the second argument. |
static String | toUnsignedString(long i) | Returns a string representation of the argument as an unsigned decimal value. |
static String | toUnsignedString(long i,
int radix) | Returns a string representation of the first argument as an unsigned integer value in the radix specified by the second argument. |
static Long | valueOf(long l) | Returns a |
static Long | valueOf(String s) | Returns a |
static Long | valueOf(String s,
int radix) | Returns a |
Methods declared in class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Field Detail
MIN_VALUE
@Native public static final long MIN_VALUE
A constant holding the minimum value a long
can have, -263.
- See Also:
- Constant Field Values
MAX_VALUE
@Native public static final long MAX_VALUE
A constant holding the maximum value a long
can have, 263-1.
- See Also:
- Constant Field Values
TYPE
public static final Class<Long> TYPE
The Class
instance representing the primitive type long
.
- Since:
- 1.1
SIZE
@Native public static final int SIZE
The number of bits used to represent a long
value in two's complement binary form.
- Since:
- 1.5
- See Also:
- Constant Field Values
BYTES
public static final int BYTES
The number of bytes used to represent a long
value in two's complement binary form.
- Since:
- 1.8
- See Also:
- Constant Field Values
Constructor Detail
Long
@Deprecated(since="9") public Long(long value)
valueOf(long)
is generally a better choice, as it is likely to yield significantly better space and time performance.Constructs a newly allocated Long
object that represents the specified long
argument.
- Parameters:
-
value
- the value to be represented by theLong
object.
Long
@Deprecated(since="9") public Long(String s) throws NumberFormatException
parseLong(String)
to convert a string to a long
primitive, or use valueOf(String)
to convert a string to a Long
object.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
- theString
to be converted to aLong
. - Throws:
-
NumberFormatException
- if theString
does not contain a parsablelong
.
Method Detail
toString
public static 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:
0123456789abcdefghijklmnopqrstuvwxyzThese 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 String.toUpperCase()
method may be called on the result: Long.toString(n, 16).toUpperCase()
- Parameters:
-
i
- along
to be converted to a string. -
radix
- the radix to use in the string representation. - Returns:
- a string representation of the argument in the specified radix.
- See Also:
-
Character.MAX_RADIX
,Character.MIN_RADIX
toUnsignedString
public static String toUnsignedString(long i, int radix)
Returns a string representation of the first argument as an unsigned integer value 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.
Note that since the first argument is treated as an unsigned value, no leading sign character is printed.
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 behavior of radixes and the characters used as digits are the same as toString
.
- Parameters:
-
i
- an integer to be converted to an unsigned string. -
radix
- the radix to use in the string representation. - Returns:
- an unsigned string representation of the argument in the specified radix.
- Since:
- 1.8
- See Also:
toString(long, int)
toHexString
public static 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 264 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.
The value of the argument can be recovered from the returned string s
by calling Long.parseUnsignedLong(s,
16)
.
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:
0123456789abcdefThese 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()
- Parameters:
-
i
- along
to be converted to a string. - Returns:
- the string representation of the unsigned
long
value represented by the argument in hexadecimal (base 16). - Since:
- 1.0.2
- See Also:
-
parseUnsignedLong(String, int)
,toUnsignedString(long, int)
toOctalString
public static 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 264 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.
The value of the argument can be recovered from the returned string s
by calling Long.parseUnsignedLong(s,
8)
.
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:
01234567These are the characters
'\u0030'
through '\u0037'
.- Parameters:
-
i
- along
to be converted to a string. - Returns:
- the string representation of the unsigned
long
value represented by the argument in octal (base 8). - Since:
- 1.0.2
- See Also:
-
parseUnsignedLong(String, int)
,toUnsignedString(long, int)
toBinaryString
public static 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 264 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.
The value of the argument can be recovered from the returned string s
by calling Long.parseUnsignedLong(s,
2)
.
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
- along
to be converted to a string. - Returns:
- the string representation of the unsigned
long
value represented by the argument in binary (base 2). - Since:
- 1.0.2
- See Also:
-
parseUnsignedLong(String, int)
,toUnsignedString(long, int)
toString
public static 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
- along
to be converted. - Returns:
- a string representation of the argument in base 10.
toUnsignedString
public static String toUnsignedString(long i)
Returns a string representation of the argument as an unsigned decimal value. The argument is converted to unsigned decimal representation and returned as a string exactly as if the argument and radix 10 were given as arguments to the toUnsignedString(long,
int)
method.
- Parameters:
-
i
- an integer to be converted to an unsigned string. - Returns:
- an unsigned string representation of the argument.
- Since:
- 1.8
- See Also:
toUnsignedString(long, int)
parseLong
public static long parseLong(String s, int radix) throws NumberFormatException
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 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 or equal to 22.
An exception of type NumberFormatException
is thrown if any of the following situations occurs:
- The first argument is
null
or is a string of length zero. - The
radix
is either smaller thanCharacter.MIN_RADIX
or larger thanCharacter.MAX_RADIX
. - Any character of the string is not a digit of the specified radix, except that the first character may be a minus sign
'-'
('\u002d'
) or plus sign'+'
('\u002B'
) provided that the string is longer than length 1. - The value represented by the string is not a value of type
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
- theString
containing thelong
representation to be parsed. -
radix
- the radix to be used while parsings
. - Returns:
- the
long
represented by the string argument in the specified radix. - Throws:
-
NumberFormatException
- if the string does not contain a parsablelong
.
parseLong
public static long parseLong(CharSequence s, int beginIndex, int endIndex, int radix) throws NumberFormatException
Parses the CharSequence
argument as a signed long
in the specified radix
, beginning at the specified beginIndex
and extending to endIndex - 1
.
The method does not take steps to guard against the CharSequence
being mutated while parsing.
- Parameters:
-
s
- theCharSequence
containing thelong
representation to be parsed -
beginIndex
- the beginning index, inclusive. -
endIndex
- the ending index, exclusive. -
radix
- the radix to be used while parsings
. - Returns:
- the signed
long
represented by the subsequence in the specified radix. - Throws:
-
NullPointerException
- ifs
is null. -
IndexOutOfBoundsException
- ifbeginIndex
is negative, or ifbeginIndex
is greater thanendIndex
or ifendIndex
is greater thans.length()
. -
NumberFormatException
- if theCharSequence
does not contain a parsableint
in the specifiedradix
, or ifradix
is either smaller thanCharacter.MIN_RADIX
or larger thanCharacter.MAX_RADIX
. - Since:
- 9
parseLong
public static long parseLong(String s) throws NumberFormatException
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
- aString
containing thelong
representation to be parsed - Returns:
- the
long
represented by the argument in decimal. - Throws:
-
NumberFormatException
- if the string does not contain a parsablelong
.
parseUnsignedLong
public static long parseUnsignedLong(String s, int radix) throws NumberFormatException
Parses the string argument as an unsigned long
in the radix specified by the second argument. An unsigned integer maps the values usually associated with negative numbers to positive numbers larger than MAX_VALUE
. 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 plus sign '+'
('\u002B'
). The resulting integer value is returned.
An exception of type NumberFormatException
is thrown if any of the following situations occurs:
- The first argument is
null
or is a string of length zero. - The radix is either smaller than
Character.MIN_RADIX
or larger thanCharacter.MAX_RADIX
. - Any character of the string is not a digit of the specified radix, except that the first character may be a plus sign
'+'
('\u002B'
) provided that the string is longer than length 1. - The value represented by the string is larger than the largest unsigned
long
, 264-1.
- Parameters:
-
s
- theString
containing the unsigned integer representation to be parsed -
radix
- the radix to be used while parsings
. - Returns:
- the unsigned
long
represented by the string argument in the specified radix. - Throws:
-
NumberFormatException
- if theString
does not contain a parsablelong
. - Since:
- 1.8
parseUnsignedLong
public static long parseUnsignedLong(CharSequence s, int beginIndex, int endIndex, int radix) throws NumberFormatException
Parses the CharSequence
argument as an unsigned long
in the specified radix
, beginning at the specified beginIndex
and extending to endIndex - 1
.
The method does not take steps to guard against the CharSequence
being mutated while parsing.
- Parameters:
-
s
- theCharSequence
containing the unsignedlong
representation to be parsed -
beginIndex
- the beginning index, inclusive. -
endIndex
- the ending index, exclusive. -
radix
- the radix to be used while parsings
. - Returns:
- the unsigned
long
represented by the subsequence in the specified radix. - Throws:
-
NullPointerException
- ifs
is null. -
IndexOutOfBoundsException
- ifbeginIndex
is negative, or ifbeginIndex
is greater thanendIndex
or ifendIndex
is greater thans.length()
. -
NumberFormatException
- if theCharSequence
does not contain a parsable unsignedlong
in the specifiedradix
, or ifradix
is either smaller thanCharacter.MIN_RADIX
or larger thanCharacter.MAX_RADIX
. - Since:
- 9
parseUnsignedLong
public static long parseUnsignedLong(String s) throws NumberFormatException
Parses the string argument as an unsigned decimal long
. The characters in the string must all be decimal digits, except that the first character may be an ASCII plus sign
'+'
('\u002B'
). The resulting integer value is returned, exactly as if the argument and the radix 10 were given as arguments to the parseUnsignedLong(java.lang.String, int)
method.
- Parameters:
-
s
- aString
containing the unsignedlong
representation to be parsed - Returns:
- the unsigned
long
value represented by the decimal string argument - Throws:
-
NumberFormatException
- if the string does not contain a parsable unsigned integer. - Since:
- 1.8
valueOf
public static Long valueOf(String s, int radix) throws NumberFormatException
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
- the string to be parsed -
radix
- the radix to be used in interpretings
- Returns:
- a
Long
object holding the value represented by the string argument in the specified radix. - Throws:
-
NumberFormatException
- If theString
does not contain a parsablelong
.
valueOf
public static Long valueOf(String s) throws NumberFormatException
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
- the string to be parsed. - Returns:
- a
Long
object holding the value represented by the string argument. - Throws:
-
NumberFormatException
- If the string cannot be parsed as along
.
valueOf
public static 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. This method will always cache values in the range -128 to 127, inclusive, and may cache other values outside of this range.
- Parameters:
-
l
- a long value. - Returns:
- a
Long
instance representingl
. - Since:
- 1.5
decode
public static Long decode(String nm) throws NumberFormatException
Decodes a String
into a Long
. Accepts decimal, hexadecimal, and octal numbers given by the following grammar:
- DecodableString:
-
Signopt DecimalNumeral
- Signopt
0x
HexDigits- Signopt
0X
HexDigits- Signopt
#
HexDigits- Signopt
0
OctalDigits - Signopt
- 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
- theString
to decode. - Returns:
- a
Long
object holding thelong
value represented bynm
- Throws:
-
NumberFormatException
- if theString
does not contain a parsablelong
. - Since:
- 1.2
- See Also:
parseLong(String, int)
byteValue
public byte byteValue()
Returns the value of this Long
as a byte
after a narrowing primitive conversion.
- Overrides:
-
byteValue
in classNumber
- Returns:
- the numeric value represented by this object after conversion to type
byte
.
shortValue
public short shortValue()
Returns the value of this Long
as a short
after a narrowing primitive conversion.
- Overrides:
-
shortValue
in classNumber
- Returns:
- the numeric value represented by this object after conversion to type
short
.
intValue
public int intValue()
Returns the value of this Long
as an int
after a narrowing primitive conversion.
- Specified by:
-
intValue
in classNumber
- Returns:
- the numeric value represented by this object after conversion to type
int
.
longValue
public long longValue()
Returns the value of this Long
as a long
value.
- Specified by:
-
longValue
in classNumber
- Returns:
- the numeric value represented by this object after conversion to type
long
.
floatValue
public float floatValue()
Returns the value of this Long
as a float
after a widening primitive conversion.
- Specified by:
-
floatValue
in classNumber
- Returns:
- the numeric value represented by this object after conversion to type
float
.
doubleValue
public double doubleValue()
Returns the value of this Long
as a double
after a widening primitive conversion.
- Specified by:
-
doubleValue
in classNumber
- Returns:
- the numeric value represented by this object after conversion to type
double
.
toString
public 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.
- Overrides:
-
toString
in classObject
- Returns:
- a string representation of the value of this object in base 10.
hashCode
public 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))
- Overrides:
-
hashCode
in classObject
- Returns:
- a hash code value for this object.
- See Also:
-
Object.equals(java.lang.Object)
,System.identityHashCode(java.lang.Object)
hashCode
public static int hashCode(long value)
Returns a hash code for a long
value; compatible with Long.hashCode()
.
- Parameters:
-
value
- the value to hash - Returns:
- a hash code value for a
long
value. - Since:
- 1.8
equals
public 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.
- Overrides:
-
equals
in classObject
- Parameters:
-
obj
- the object to compare with. - Returns:
-
true
if the objects are the same;false
otherwise. - See Also:
-
Object.hashCode()
,HashMap
getLong
public static 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 System.getProperty(java.lang.String)
method. The string value of this property is then interpreted as a
long
value using the grammar supported by decode
and a Long
object representing this value is returned.
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
- property name. - Returns:
- the
Long
value of the property. - Throws:
-
SecurityException
- for the same reasons asSystem.getProperty
- See Also:
-
System.getProperty(java.lang.String)
,System.getProperty(java.lang.String, java.lang.String)
getLong
public static 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 System.getProperty(java.lang.String)
method. The string value of this property is then interpreted as a
long
value using the grammar supported by decode
and a Long
object representing this value is returned.
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:
Long result = getLong(nm, null); return (result == null) ? new Long(val) : result;to avoid the unnecessary allocation of a
Long
object when the default value is not needed.- Parameters:
-
nm
- property name. -
val
- default value. - Returns:
- the
Long
value of the property. - Throws:
-
SecurityException
- for the same reasons asSystem.getProperty
- See Also:
-
System.getProperty(java.lang.String)
,System.getProperty(java.lang.String, java.lang.String)
getLong
public static 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 System.getProperty(java.lang.String)
method. The string value of this property is then interpreted as a long
value, as per the decode
method, and a Long
object representing this value is returned; in summary:
- If the property value begins with the two ASCII characters
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 methodvalueOf(java.lang.String, int)
with radix 16. - If the property value begins with the ASCII character
0
followed by another character, it is parsed as an octal integer exactly as by the methodvalueOf(java.lang.String, int)
with radix 8. - Otherwise the property value is parsed as a decimal integer exactly as by the method
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
- property name. -
val
- default value. - Returns:
- the
Long
value of the property. - Throws:
-
SecurityException
- for the same reasons asSystem.getProperty
- See Also:
-
System.getProperty(java.lang.String)
,System.getProperty(java.lang.String, java.lang.String)
compareTo
public int compareTo(Long anotherLong)
Compares two Long
objects numerically.
- Specified by:
-
compareTo
in interfaceComparable<Long>
- Parameters:
-
anotherLong
- theLong
to be compared. - Returns:
- the value
0
if thisLong
is equal to the argumentLong
; a value less than0
if thisLong
is numerically less than the argumentLong
; and a value greater than0
if thisLong
is numerically greater than the argumentLong
(signed comparison). - Since:
- 1.2
compare
public static 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
- the firstlong
to compare -
y
- the secondlong
to compare - Returns:
- the value
0
ifx == y
; a value less than0
ifx < y
; and a value greater than0
ifx > y
- Since:
- 1.7
compareUnsigned
public static int compareUnsigned(long x, long y)
Compares two long
values numerically treating the values as unsigned.
- Parameters:
-
x
- the firstlong
to compare -
y
- the secondlong
to compare - Returns:
- the value
0
ifx == y
; a value less than0
ifx < y
as unsigned values; and a value greater than0
ifx > y
as unsigned values - Since:
- 1.8
divideUnsigned
public static long divideUnsigned(long dividend, long divisor)
Returns the unsigned quotient of dividing the first argument by the second where each argument and the result is interpreted as an unsigned value.
Note that in two's complement arithmetic, the three other basic arithmetic operations of add, subtract, and multiply are bit-wise identical if the two operands are regarded as both being signed or both being unsigned. Therefore separate
addUnsigned
, etc. methods are not provided.
- Parameters:
-
dividend
- the value to be divided -
divisor
- the value doing the dividing - Returns:
- the unsigned quotient of the first argument divided by the second argument
- Since:
- 1.8
- See Also:
remainderUnsigned(long, long)
remainderUnsigned
public static long remainderUnsigned(long dividend, long divisor)
Returns the unsigned remainder from dividing the first argument by the second where each argument and the result is interpreted as an unsigned value.
- Parameters:
-
dividend
- the value to be divided -
divisor
- the value doing the dividing - Returns:
- the unsigned remainder of the first argument divided by the second argument
- Since:
- 1.8
- See Also:
divideUnsigned(long, long)
highestOneBit
public static long highestOneBit(long i)
Returns a long
value with at most a single one-bit, in the position of the highest-order ("leftmost") one-bit in the specified long
value. Returns zero if the specified value has no one-bits in its two's complement binary representation, that is, if it is equal to zero.
- Parameters:
-
i
- the value whose highest one bit is to be computed - Returns:
- a
long
value with a single one-bit, in the position of the highest-order one-bit in the specified value, or zero if the specified value is itself equal to zero. - Since:
- 1.5
lowestOneBit
public static long lowestOneBit(long i)
Returns a long
value with at most a single one-bit, in the position of the lowest-order ("rightmost") one-bit in the specified long
value. Returns zero if the specified value has no one-bits in its two's complement binary representation, that is, if it is equal to zero.
- Parameters:
-
i
- the value whose lowest one bit is to be computed - Returns:
- a
long
value with a single one-bit, in the position of the lowest-order one-bit in the specified value, or zero if the specified value is itself equal to zero. - Since:
- 1.5
numberOfLeadingZeros
public static int numberOfLeadingZeros(long i)
Returns the number of zero bits preceding the highest-order ("leftmost") one-bit in the two's complement binary representation of the specified long
value. Returns 64 if the specified value has no one-bits 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:
- floor(log2(x)) =
63 - numberOfLeadingZeros(x)
- ceil(log2(x)) =
64 - numberOfLeadingZeros(x - 1)
- Parameters:
-
i
- the value whose number of leading zeros is to be computed - Returns:
- the number of zero bits preceding the highest-order ("leftmost") one-bit in the two's complement binary representation of the specified
long
value, or 64 if the value is equal to zero. - Since:
- 1.5
numberOfTrailingZeros
public static int numberOfTrailingZeros(long i)
Returns the number of zero bits following the lowest-order ("rightmost") one-bit in the two's complement binary representation of the specified long
value. Returns 64 if the specified value has no one-bits in its two's complement representation, in other words if it is equal to zero.
- Parameters:
-
i
- the value whose number of trailing zeros is to be computed - Returns:
- the number of zero bits following the lowest-order ("rightmost") one-bit in the two's complement binary representation of the specified
long
value, or 64 if the value is equal to zero. - Since:
- 1.5
bitCount
public static int bitCount(long i)
Returns the number of one-bits in the two's complement binary representation of the specified long
value. This function is sometimes referred to as the population count.
- Parameters:
-
i
- the value whose bits are to be counted - Returns:
- the number of one-bits in the two's complement binary representation of the specified
long
value. - Since:
- 1.5
rotateLeft
public 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. (Bits shifted out of the left hand, or high-order, side reenter on the right, or low-order.)
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 no-op, 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
- the value whose bits are to be rotated left -
distance
- the number of bit positions to rotate left - Returns:
- the value obtained by rotating the two's complement binary representation of the specified
long
value left by the specified number of bits. - Since:
- 1.5
rotateRight
public 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. (Bits shifted out of the right hand, or low-order, side reenter on the left, or high-order.)
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 no-op, 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
- the value whose bits are to be rotated right -
distance
- the number of bit positions to rotate right - Returns:
- the value obtained by rotating the two's complement binary representation of the specified
long
value right by the specified number of bits. - Since:
- 1.5
reverse
public 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.
- Parameters:
-
i
- the value to be reversed - Returns:
- the value obtained by reversing order of the bits in the specified
long
value. - Since:
- 1.5
signum
public static 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
- the value whose signum is to be computed - Returns:
- the signum function of the specified
long
value. - Since:
- 1.5
reverseBytes
public 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.
- Parameters:
-
i
- the value whose bytes are to be reversed - Returns:
- the value obtained by reversing the bytes in the specified
long
value. - Since:
- 1.5
sum
public static long sum(long a, long b)
Adds two long
values together as per the + operator.
- Parameters:
-
a
- the first operand -
b
- the second operand - Returns:
- the sum of
a
andb
- Since:
- 1.8
- See Also:
BinaryOperator
max
public static long max(long a, long b)
Returns the greater of two long
values as if by calling Math.max
.
- Parameters:
-
a
- the first operand -
b
- the second operand - Returns:
- the greater of
a
andb
- Since:
- 1.8
- See Also:
BinaryOperator
min
public static long min(long a, long b)
Returns the smaller of two long
values as if by calling Math.min
.
- Parameters:
-
a
- the first operand -
b
- the second operand - Returns:
- the smaller of
a
andb
- Since:
- 1.8
- See Also:
BinaryOperator