Class Long
- java.lang.Object
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- java.lang.Number
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- java.lang.Long
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- All Implemented Interfaces:
Serializable,Comparable<Long>
public final class Long extends Number implements Comparable<Long>
TheLongclass wraps a value of the primitive typelongin an object. An object of typeLongcontains a single field whose type islong.In addition, this class provides several methods for converting a
longto aStringand aStringto along, as well as other constants and methods useful when dealing with along.- See Also:
- Serialized Form
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Field Summary
Fields Modifier and Type Field Description static longMAX_VALUEA constant holding the maximum value alongcan have, 263-1.static longMIN_VALUEA constant holding the minimum value alongcan have, -263.static intSIZEThe number of bits used to represent alongvalue in two's complement binary form.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description bytebyteValue()Returns the value of thisLongas abyte.static intcompare(long x, long y)Compares twolongvalues numerically.intcompareTo(Long anotherLong)Compares twoLongobjects numerically.static Longdecode(String nm)Decodes aStringinto aLong.doubledoubleValue()Returns the value of thisLongas adouble.booleanequals(Object obj)Compares this object to the specified object.floatfloatValue()Returns the value of thisLongas afloat.static LonggetLong(String nm)Determines thelongvalue of the system property with the specified name.static LonggetLong(String nm, long val)Determines thelongvalue of the system property with the specified name.static LonggetLong(String nm, Long val)Returns thelongvalue of the system property with the specified name.inthashCode()Returns a hash code for thisLong.intintValue()Returns the value of thisLongas anint.longlongValue()Returns the value of thisLongas alongvalue.static longparseLong(String s)Parses the string argument as a signed decimallong.static longparseLong(String s, int radix)Parses the string argument as a signedlongin the radix specified by the second argument.static longrotateLeft(long i, int distance)Returns the value obtained by rotating the two's complement binary representation of the specifiedlongvalue left by the specified number of bits.static longrotateRight(long i, int distance)Returns the value obtained by rotating the two's complement binary representation of the specifiedlongvalue right by the specified number of bits.shortshortValue()Returns the value of thisLongas ashort.static intsignum(long i)Returns the signum function of the specifiedlongvalue.static StringtoBinaryString(long i)Returns a string representation of thelongargument as an unsigned integer in base 2.static StringtoHexString(long i)Returns a string representation of thelongargument as an unsigned integer in base 16.StringtoString()Returns aStringobject representing thisLong's value.static StringtoString(long i)Returns aStringobject representing the specifiedlong.static StringtoString(long i, int radix)Returns a string representation of the first argument in the radix specified by the second argument.static LongvalueOf(long l)Returns aLonginstance representing the specifiedlongvalue.static LongvalueOf(String s)Returns aLongobject holding the value of the specifiedString.static LongvalueOf(String s, int radix)Returns aLongobject holding the value extracted from the specifiedStringwhen parsed with the radix given by the second argument.
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Field Detail
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MAX_VALUE
public static final long MAX_VALUE
A constant holding the maximum value alongcan have, 263-1.- See Also:
- Constant Field Values
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MIN_VALUE
public static final long MIN_VALUE
A constant holding the minimum value alongcan have, -263.- See Also:
- Constant Field Values
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SIZE
public static final int SIZE
The number of bits used to represent alongvalue in two's complement binary form.- See Also:
- Constant Field Values
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Constructor Detail
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Long
public Long(long value)
Constructs a newly allocatedLongobject that represents the specifiedlongargument.- Parameters:
value- the value to be represented by theLongobject.
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Long
public Long(String s) throws NumberFormatException
Constructs a newly allocatedLongobject that represents thelongvalue indicated by theStringparameter. The string is converted to alongvalue in exactly the manner used by theparseLongmethod for radix 10.Null Analysis restriction: the parameter s is
@NonNull, to ensure thatNumberFormatExceptionis thrown only when the string characters do not represent a valid number. This aligns with the behavior ofFloat.parseFloat(String)andDouble.parseDouble(String).- Parameters:
s- theStringto be converted to aLong.- Throws:
NumberFormatException- if theStringdoes not contain a parsablelong.- See Also:
parseLong(java.lang.String, int)
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Method Detail
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compare
public static int compare(long x, long y)Compares twolongvalues numerically. The value returned is identical to what would be returned by:Long.valueOf(x).compareTo(Long.valueOf(y))
- Parameters:
x- the firstlongto comparey- the secondlongto compare- Returns:
- the value
0ifx == y; a value less than0ifx < y; and a value greater than0ifx > y
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decode
public static Long decode(String nm) throws NumberFormatException
Decodes aStringinto aLong. Accepts decimal, hexadecimal, and octal numbers given by the following grammar:
DecimalNumeral, HexDigits, and OctalDigits are as defined in section 3.10.1 of The Java™ Language Specification, except that underscores are not accepted between digits.- DecodableString:
- Signopt DecimalNumeral
- Signopt
0xHexDigits- Signopt
0XHexDigits- Signopt
#HexDigits- Signopt
0OctalDigits - Signopt
- Sign:
-+
The sequence of characters following an optional sign and/or radix specifier ("
0x", "0X", "#", or leading zero) is parsed as by theLong.parseLongmethod with the indicated radix (10, 16, or 8). This sequence of characters must represent a positive value or aNumberFormatExceptionwill be thrown. The result is negated if first character of the specifiedStringis the minus sign. No whitespace characters are permitted in theString.- Parameters:
nm- theStringto decode.- Returns:
- a
Longobject holding thelongvalue represented bynm - Throws:
NumberFormatException- if theStringdoes not contain a parsablelong.- See Also:
parseLong(String, int)
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getLong
@Nullable public static Long getLong(String nm)
Determines thelongvalue 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 alongvalue and aLongobject representing this value is returned. Details of possible numeric formats can be found with the definition ofgetProperty.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, thennullis returned.In other words, this method returns a
Longobject equal to the value of:getLong(nm, null)- Parameters:
nm- property name.- Returns:
- the
Longvalue of the property. - See Also:
System.getProperty(java.lang.String),System.getProperty(java.lang.String, java.lang.String)
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getLong
public static Long getLong(String nm, long val)
Determines thelongvalue 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 alongvalue and aLongobject representing this value is returned. Details of possible numeric formats can be found with the definition ofgetProperty.The second argument is the default value. A
Longobject 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
Longobject 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 aLong result = getLong(nm, null); return (result == null) ? new Long(val) : result;
Longobject when the default value is not needed.- Parameters:
nm- property name.val- default value.- Returns:
- the
Longvalue of the property. - See Also:
System.getProperty(java.lang.String),System.getProperty(java.lang.String, java.lang.String)
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getLong
public static Long getLong(String nm, Long val)
Returns thelongvalue 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 theSystem.getProperty(java.lang.String)method. The string value of this property is then interpreted as alongvalue, as per theLong.decodemethod, and aLongobject representing this value is returned.- If the property value begins with the two ASCII characters
0xor 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
0followed 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') norl('\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
Longvalue of the property. - See Also:
System.getProperty(java.lang.String),System.getProperty(java.lang.String, java.lang.String),decode(java.lang.String)
- If the property value begins with the two ASCII characters
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parseLong
public static long parseLong(String s) throws NumberFormatException
Parses the string argument as a signed decimallong. 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 resultinglongvalue is returned, exactly as if the argument and the radix10were given as arguments to theparseLong(java.lang.String, int)method.Note that neither the character
L('\u004C') norl('\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.Null Analysis restriction: the parameter s is
@NonNull, to ensure thatNumberFormatExceptionis thrown only when the string characters do not represent a valid number. This aligns with the behavior ofFloat.parseFloat(String)andDouble.parseDouble(String).- Parameters:
s- aStringcontaining thelongrepresentation to be parsed- Returns:
- the
longrepresented by the argument in decimal. - Throws:
NumberFormatException- if the string does not contain a parsablelong.
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parseLong
public static long parseLong(String s, int radix) throws NumberFormatException
Parses the string argument as a signedlongin the radix specified by the second argument. The characters in the string must all be digits of the specified radix (as determined by whetherCharacter.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 resultinglongvalue is returned.Note that neither the character
L('\u004C') norl('\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 eitherLorlmay appear as a digit for a radix greater than 22.An exception of type
NumberFormatExceptionis thrown if any of the following situations occurs:- The first argument is
nullor is a string of length zero. - The
radixis either smaller thanCharacter.MIN_RADIXor 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 1356099454469LNull Analysis restriction: the parameter s is
@NonNull, to ensure thatNumberFormatExceptionis thrown only when the string characters do not represent a valid number. This aligns with the behavior ofFloat.parseFloat(String)andDouble.parseDouble(String).- Parameters:
s- theStringcontaining thelongrepresentation to be parsed.radix- the radix to be used while parsings.- Returns:
- the
longrepresented by the string argument in the specified radix. - Throws:
NumberFormatException- if the string does not contain a parsablelong.
- The first argument is
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rotateLeft
public static long rotateLeft(long i, int distance)Returns the value obtained by rotating the two's complement binary representation of the specifiedlongvalue 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 leftdistance- the number of bit positions to rotate left- Returns:
- the value obtained by rotating the two's complement binary representation of the
specified
longvalue left by the specified number of bits.
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rotateRight
public static long rotateRight(long i, int distance)Returns the value obtained by rotating the two's complement binary representation of the specifiedlongvalue 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 rightdistance- the number of bit positions to rotate right- Returns:
- the value obtained by rotating the two's complement binary representation of the
specified
longvalue right by the specified number of bits.
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signum
public static int signum(long i)
Returns the signum function of the specifiedlongvalue. (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
longvalue.
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toBinaryString
public static String toBinaryString(long i)
Returns a string representation of thelongargument as an unsigned integer in base 2.The unsigned
longvalue 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 leading0s. 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- alongto be converted to a string.- Returns:
- the string representation of the unsigned
longvalue represented by the argument in binary (base 2).
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toHexString
public static String toHexString(long i)
Returns a string representation of thelongargument as an unsigned integer in base 16.The unsigned
longvalue 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 leading0s. 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, theString.toUpperCase()method may be called on the result:Long.toHexString(n).toUpperCase()- Parameters:
i- alongto be converted to a string.- Returns:
- the string representation of the unsigned
longvalue represented by the argument in hexadecimal (base 16).
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toString
public static String toString(long i)
Returns aStringobject representing the specifiedlong. 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 thetoString(long, int)method.- Parameters:
i- alongto be converted.- Returns:
- a string representation of the argument in base 10.
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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_RADIXor larger thanCharacter.MAX_RADIX, then the radix10is 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'. Ifradixis 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) are0123456789abcdef. If uppercase letters are desired, theString.toUpperCase()method may be called on the result:Long.toString(n, 16).toUpperCase()- Parameters:
i- alongto 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
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valueOf
public static Long valueOf(long l)
Returns aLonginstance representing the specifiedlongvalue. If a newLonginstance is not required, this method should generally be used in preference to the constructorLong(long), as this method is likely to yield significantly better space and time performance by caching frequently requested values. Note that unlike the corresponding method in theIntegerclass, this method is not required to cache values within a particular range.- Parameters:
l- a long value.- Returns:
- a
Longinstance representingl.
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valueOf
public static Long valueOf(String s) throws NumberFormatException
Returns aLongobject holding the value of the specifiedString. The argument is interpreted as representing a signed decimallong, exactly as if the argument were given to theparseLong(java.lang.String)method. The result is aLongobject that represents the integer value specified by the string.In other words, this method returns a
Longobject equal to the value of:new Long(Long.parseLong(s))Null Analysis restriction: the parameter s is
@NonNull, to ensure thatNumberFormatExceptionis thrown only when the string characters do not represent a valid number. This aligns with the behavior ofFloat.parseFloat(String)andDouble.parseDouble(String).- Parameters:
s- the string to be parsed.- Returns:
- a
Longobject holding the value represented by the string argument. - Throws:
NumberFormatException- If the string cannot be parsed as along.
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valueOf
public static Long valueOf(String s, int radix) throws NumberFormatException
Returns aLongobject holding the value extracted from the specifiedStringwhen parsed with the radix given by the second argument. The first argument is interpreted as representing a signedlongin the radix specified by the second argument, exactly as if the arguments were given to theparseLong(java.lang.String, int)method. The result is aLongobject that represents thelongvalue specified by the string.In other words, this method returns a
Longobject equal to the value of:new Long(Long.parseLong(s, radix))Null Analysis restriction: the parameter s is
@NonNull, to ensure thatNumberFormatExceptionis thrown only when the string characters do not represent a valid number. This aligns with the behavior ofFloat.parseFloat(String)andDouble.parseDouble(String).- Parameters:
s- the string to be parsedradix- the radix to be used in interpretings- Returns:
- a
Longobject holding the value represented by the string argument in the specified radix. - Throws:
NumberFormatException- If theStringdoes not contain a parsablelong.
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byteValue
public byte byteValue()
Returns the value of thisLongas abyte.
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compareTo
public int compareTo(Long anotherLong)
Compares twoLongobjects numerically.- Specified by:
compareToin interfaceComparable<Long>- Parameters:
anotherLong- theLongto be compared.- Returns:
- the value
0if thisLongis equal to the argumentLong; a value less than0if thisLongis numerically less than the argumentLong; and a value greater than0if thisLongis numerically greater than the argumentLong(signed comparison).
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doubleValue
public double doubleValue()
Returns the value of thisLongas adouble.- Specified by:
doubleValuein classNumber- Returns:
- the numeric value represented by this object after conversion to type
double.
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equals
public boolean equals(@Nullable Object obj)
Compares this object to the specified object. The result istrueif and only if the argument is notnulland is aLongobject that contains the samelongvalue as this object.- Overrides:
equalsin classObject- Parameters:
obj- the object to compare with.- Returns:
trueif the objects are the same;falseotherwise.- See Also:
Object.hashCode(),HashMap
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floatValue
public float floatValue()
Returns the value of thisLongas afloat.- Specified by:
floatValuein classNumber- Returns:
- the numeric value represented by this object after conversion to type
float.
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hashCode
public int hashCode()
Returns a hash code for thisLong. The result is the exclusive OR of the two halves of the primitivelongvalue held by thisLongobject. That is, the hashcode is the value of the expression:(int)(this.longValue()^(this.longValue()>>>32))- Overrides:
hashCodein classObject- Returns:
- a hash code value for this object.
- See Also:
Object.equals(java.lang.Object),System.identityHashCode(java.lang.Object)
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intValue
public int intValue()
Returns the value of thisLongas anint.
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longValue
public long longValue()
Returns the value of thisLongas alongvalue.
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shortValue
public short shortValue()
Returns the value of thisLongas ashort.- Overrides:
shortValuein classNumber- Returns:
- the numeric value represented by this object after conversion to type
short.
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toString
public String toString()
Returns aStringobject representing thisLong's value. The value is converted to signed decimal representation and returned as a string, exactly as if thelongvalue were given as an argument to thetoString(long)method.
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