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.
Since: JDK1.0
Version: 1.71, 07/09/03
| Field Summary | |
|---|---|
| static long | MAX_VALUE
A constant holding the maximum value a long can
have, 263-1. |
| static long | MIN_VALUE
A constant holding the minimum value a long can
have, -263. |
| 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 | |
|---|---|
| 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. |
| 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 | parseLong(String s, int radix)
Parses the string argument as a signed long in the
radix specified by the second argument. |
| static long | parseLong(String s)
Parses the string argument as a signed decimal
long. |
| short | shortValue()
Returns the value of this Long as a
short. |
| 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.
|
| 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 | toString(long i)
Returns a String object representing the specified
long. |
| String | toString()
Returns a String object representing this
Long's value. |
| 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. |
| static Long | valueOf(String s)
Returns a Long object holding the value
of the specified String. |
| static Long | valueOf(long l)
Returns a Long instance representing the specified
long value.
|
long can
have, 263-1.long can
have, -263.Class instance representing the primitive type
long.
Since: JDK1.1
Long object that
represents the specified long argument.
Parameters: value the value to be represented by the
Long object.
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 the String to be converted to a
Long.
Throws: NumberFormatException if the String does not
contain a parsable long.
See Also: Long
Long as a
byte.Long objects numerically.
Parameters: anotherLong the Long to be compared.
Returns: the value 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).
Since: 1.2
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:
- Signopt DecimalNumeral
- Signopt
0xHexDigits- Signopt
0XHexDigits- Signopt
#HexDigits- Signopt
0OctalDigits
- 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.
Parameters: nm the String to decode.
Returns: a Long object holding the long
value represented by nm
Throws: NumberFormatException if the String does not
contain a parsable long.
Since: 1.2
See Also: Long
Long as a
double.true if and only if the argument is not
null and is a Long object that
contains the same long value as this object.
Parameters: obj the object to compare with.
Returns: true if the objects are the same;
false otherwise.
Long as a
float.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 java.lang.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)
Parameters: nm property name.
Returns: the Long value of the property.
See Also: java.lang.System#getProperty(java.lang.String) java.lang.System#getProperty(java.lang.String, java.lang.String)
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 java.lang.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))
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.
Parameters: nm property name. val default value.
Returns: the Long value of the property.
See Also: java.lang.System#getProperty(java.lang.String) java.lang.System#getProperty(java.lang.String, java.lang.String)
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 java.lang.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 Long
with radix 16.
0 followed by another character, it is parsed as
an octal integer exactly as by the method Long with radix 8.
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.
See Also: java.lang.System#getProperty(java.lang.String) java.lang.System#getProperty(java.lang.String, java.lang.String) Long
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))
Returns: a hash code value for this object.
Long as an
int.Long as a
long value.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 returns
a nonnegative value), except that the first character may be an
ASCII minus sign '-' ('\u002D') to
indicate a negative 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 MIN_RADIX or larger than MAX_RADIX.
'-' ('\u002d') provided that the
string is longer than length 1.
long.
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
Parameters: s the String containing the
long representation to be parsed. radix the radix to be used while parsing s.
Returns: the long represented by the string argument in
the specified radix.
Throws: NumberFormatException if the string does not contain a
parsable long.
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. The resulting long
value is returned, exactly as if the argument and the radix
10 were given as arguments to the Long 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 a String containing the long
representation to be parsed
Returns: the long represented by the argument in
decimal.
Throws: NumberFormatException if the string does not contain a
parsable long.
Long as a
short.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
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.
Parameters: i a long to be converted to a string.
Returns: the string representation of the unsigned long
value represented by the argument in binary (base 2).
Since: JDK 1.0.2
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 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 characters0123456789abcdef
'\u0030' through
'\u0039' and '\u0061' through
'\u0066'. If uppercase letters are desired,
the toUpperCase method may be called
on the result:
Long.toHexString(n).toUpperCase()
Parameters: i a long to be converted to a string.
Returns: the string representation of the unsigned long
value represented by the argument in hexadecimal
(base 16).
Since: JDK 1.0.2
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
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 characters01234567
'\u0030' through
'\u0037'.
Parameters: i a long to be converted to a string.
Returns: the string representation of the unsigned long
value represented by the argument in octal (base 8).
Since: JDK 1.0.2
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 are0123456789abcdefghijklmnopqrstuvwxyz
'\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 toUpperCase method may
be called on the result:
Long.toString(n, 16).toUpperCase()
Parameters: i a longto 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.
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 Long method.
Parameters: i a long to be converted.
Returns: a string representation of the argument in base 10.
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
Long method.
Returns: a string representation of the value of this object in base 10.
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 Long 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 interpreting s
Returns: a Long object holding the value
represented by the string argument in the specified
radix.
Throws: NumberFormatException If the String does not
contain a parsable long.
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 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 a long.
Parameters: l a long value.
Returns: a Long instance representing l.
Since: 1.5