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JavaTM 2 Platform Std. Ed. v1.3 |
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java.lang.Object
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+--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.
| Field Summary | |
static long |
MAX_VALUE
The largest value of type long. |
static long |
MIN_VALUE
The smallest value of type long. |
static Class |
TYPE
The Class object representing the primitive type long. |
| Constructor Summary | |
Long(long value)
Constructs a newly allocated Long object that
represents the primitive long argument. |
|
Long(String s)
Constructs a newly allocated Long object that
represents the value represented by the string in decimal form. |
|
| Method Summary | |
byte |
byteValue()
Returns the value of this Long as a byte. |
int |
compareTo(Long anotherLong)
Compares two Longs numerically. |
int |
compareTo(Object o)
Compares this Long to another Object. |
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 against 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()
Computes a hashcode 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)
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. |
short |
shortValue()
Returns the value of this Long as a short. |
static String |
toBinaryString(long i)
Creates a string representation of the long argument as an unsigned integer in base 2. |
static String |
toHexString(long i)
Creates a string representation of the long argument as an unsigned integer in base 16. |
static String |
toOctalString(long i)
Creates 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 new String object representing the specified integer. |
static String |
toString(long i,
int radix)
Creates a string representation of the first argument in the radix specified by the second argument. |
static Long |
valueOf(String s)
Returns a new long object initialized to the value of the specified String. |
static Long |
valueOf(String s,
int radix)
Returns a new long object initialized to the value of the specified String. |
| Methods inherited from class java.lang.Object |
clone, finalize, getClass, notify, notifyAll, wait, wait, wait |
| Field Detail |
public static final long MIN_VALUE
long.public static final long MAX_VALUE
long.public static final Class TYPE
| Constructor Detail |
public Long(long value)
Long object that
represents the primitive long argument.value - the value to be represented by the
Long object.
public Long(String s)
throws NumberFormatException
Long object that
represents the value represented by the string in decimal form.
The string is converted to an long value as if by the
parseLong(java.lang.String, int) method for radix 10.s - the string to be converted to a Long.NumberFormatException - if the String does not
contain a parsable long integer.valueOf(java.lang.String)| 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 the 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, the0123456789abcdefghijklmnopqrstuvwxyz
String.toUpperCase() method
may be called on the result:
Long.toString(n, 16).toUpperCase()
i - a long.radix - the radix.Character.MAX_RADIX,
Character.MIN_RADIXpublic static String toHexString(long i)
The unsigned long value is the argument plus 264 if the argument is negative; otherwise, it is equal to the argument.
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, the0123456789abcdef
String.toUpperCase() method may be called on
the result:
Long.toHexString(n).toUpperCase()
i - a long.public static String toOctalString(long i)
The unsigned long value is the argument plus 264 if the argument is negative; otherwise, it is equal to the argument.
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
i - a long.public static String toBinaryString(long i)
The unsigned long value is the argument plus 264 if the argument is negative; otherwise, it is equal to the argument.
If the unsigned magnitude is zero, it is represented by a single zero character '0' ('&392;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.
i - a long.public static String toString(long i)
toString(long, int) method that takes two arguments.i - a long to be converted.
public static long parseLong(String s,
int radix)
throws NumberFormatException
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 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 L nor l 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:
Character.MIN_RADIX or larger than
Character.MAX_RADIX.
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
s - the String containing the
long.radix - the radix to be used.long represented by the string argument in
the specified radix.NumberFormatException - if the string does not contain a
parsable integer.
public static long parseLong(String s)
throws NumberFormatException
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
parseLong(String, int) method that takes two arguments.
Note that neither L nor l is permitted to appear at the end of the string as a type indicator, as would be permitted in Java programming language source code.
s - a string.long represented by the argument in decimal.NumberFormatException - if the string does not contain a
parsable long.
public static Long valueOf(String s,
int radix)
throws NumberFormatException
The first argument is interpreted as representing a signed integer
in the radix specified by the second argument, exactly as if the
arguments were given to the parseLong(java.lang.String, int)
method that takes two arguments. 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, radix))
s - the String containing the
long.radix - the radix to be used.Long initialized to the
value represented by the string argument in the specified
radix.NumberFormatException - If the String does not
contain a parsable long.
public static Long valueOf(String s)
throws NumberFormatException
The argument is interpreted as representing a signed decimal
integer, exactly as if the argument were given to the
parseLong(java.lang.String) method that takes one argument).
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))
s - the string to be parsed.Long initialized to the
value represented by the string argument.NumberFormatException - If the String does not
contain a parsable long.
public static Long decode(String nm)
throws NumberFormatException
String into a Long. Accepts
decimal, hexadecimal, and octal numbers, in the following formats:
[-] decimal constant
[-] 0x hex constant
[-] # hex constant
[-] 0 octal constant
The constant following an (optional) negative sign and/or "radix
specifier" is parsed as by the Long.parseLong method
with the specified radix (10, 8 or 16). This constant must be positive
or a NumberFormatException will result. The result is made negative if
first character of the specified String is the negative
sign. No whitespace characters are permitted in the
String.nm - the String to decode.Long represented by the specified string.NumberFormatException - if the String does not
contain a parsable long.parseLong(String, int)public byte byteValue()
byteValue in class Numberpublic short shortValue()
shortValue in class Numberpublic int intValue()
intValue in class Numberlong value represented by this object is
converted to type int and the result of the
conversion is returned.public long longValue()
longValue in class Numberlong value represented by this object.public float floatValue()
floatValue in class Numberlong value represented by this object is
converted to type float and the result of
the conversion is returned.public double doubleValue()
doubleValue in class Numberlong value represented by this object that
is converted to type double and the result of
the conversion is returned.public String toString()
toString(long) method that takes one argument.toString in class Objectpublic int hashCode()
long value
represented by this Long object. That is, the hashcode
is the value of the expression:
(int)(this.longValue()^(this.longValue()>>>32))
hashCode in class Objectpublic boolean equals(Object obj)
true if and only if the argument is
not null and is a Long object that
contains the same long value as this object.equals in class Objectobj - the object to compare with.true if the objects are the same;
false otherwise.public static Long getLong(String nm)
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
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)
nm - property name.Long value of the property.System.getProperty(java.lang.String),
System.getProperty(java.lang.String, java.lang.String)
public static Long getLong(String nm,
long val)
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
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:
but in practice it may be implemented in a manner such as:getLong(nm, new Long(val))
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;
nm - property name.val - default value.Long value of the property.System.getProperty(java.lang.String),
System.getProperty(java.lang.String, java.lang.String)
public static Long getLong(String nm,
Long val)
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.
valueOf(java.lang.String, int)
with radix 16.
valueOf(java.lang.String, int) with radix 8.
valueOf(java.lang.String, int) with radix 10.
Note that, in every case, neither L nor l 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.
nm - property name.val - default value.Long value of the property.System.getProperty(java.lang.String),
System.getProperty(java.lang.String, java.lang.String),
decode(java.lang.String)public int compareTo(Long anotherLong)
anotherLong - the Long to be compared.0 if the argument Long is equal to
this Long; a value less than 0 if this Long
is numerically less than the Long argument; and a
value greater than 0 if this Long is
numerically greater than the Long argument
(signed comparison).public int compareTo(Object o)
compareTo(Long). Otherwise,
it throws a ClassCastException (as Longs are comparable
only to other Longs).compareTo in interface Comparableo - the Object to be compared.0 if the argument is a Long
numerically equal to this Long; a value less than
0 if the argument is a Long numerically
greater than this Long; and a value greater than
0 if the argument is a Long numerically
less than this Long.ClassCastException - if the argument is not a
Long.Comparable
|
JavaTM 2 Platform Std. Ed. v1.3 |
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