Module java.base
Package java.lang

Class Integer

  • All Implemented Interfaces:
    Serializable,Comparable<Integer>
    public final classIntegerextendsNumberimplementsComparable<Integer>
    TheInteger class wraps a value of the primitive typeint in an object. An object of typeInteger contains a single field whose type isint.

    In addition, this class provides several methods for converting anint to aString and aString to anint, as well as other constants and methods useful when dealing with anint.

    Implementation note: The implementations of the "bit twiddling" methods (such ashighestOneBit andnumberOfTrailingZeros) are based on material from Henry S. Warren, Jr.'sHacker's Delight, (Addison Wesley, 2002).

    Since:
    1.0
    See Also:
    Serialized Form

    • Field Summary

      Fields 
      Modifier and TypeFieldDescription
      static intBYTES
      The number of bytes used to represent anint value in two's complement binary form.
      static intMAX_VALUE
      A constant holding the maximum value anint can have, 231-1.
      static intMIN_VALUE
      A constant holding the minimum value anint can have, -231.
      static intSIZE
      The number of bits used to represent anint value in two's complement binary form.
      staticClass<Integer>TYPE
      TheClass instance representing the primitive typeint.

    • Constructor Summary

      Constructors 
      ConstructorDescription
      Integer​(int value)
      Deprecated.
      It is rarely appropriate to use this constructor.
      Integer​(String s)
      Deprecated.
      It is rarely appropriate to use this constructor.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and TypeMethodDescription
      static intbitCount​(int i)
      Returns the number of one-bits in the two's complement binary representation of the specifiedint value.
      bytebyteValue()
      Returns the value of thisInteger as abyte after a narrowing primitive conversion.
      static intcompare​(int x, int y)
      Compares twoint values numerically.
      intcompareTo​(Integer anotherInteger)
      Compares twoInteger objects numerically.
      static intcompareUnsigned​(int x, int y)
      Compares twoint values numerically treating the values as unsigned.
      staticIntegerdecode​(String nm)
      Decodes aString into anInteger.
      static intdivideUnsigned​(int dividend, int 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.
      doubledoubleValue()
      Returns the value of thisInteger as adouble after a widening primitive conversion.
      booleanequals​(Object obj)
      Compares this object to the specified object.
      floatfloatValue()
      Returns the value of thisInteger as afloat after a widening primitive conversion.
      staticIntegergetInteger​(String nm)
      Determines the integer value of the system property with the specified name.
      staticIntegergetInteger​(String nm, int val)
      Determines the integer value of the system property with the specified name.
      staticIntegergetInteger​(String nm,Integer val)
      Returns the integer value of the system property with the specified name.
      inthashCode()
      Returns a hash code for thisInteger.
      static inthashCode​(int value)
      Returns a hash code for anint value; compatible withInteger.hashCode().
      static inthighestOneBit​(int i)
      Returns anint value with at most a single one-bit, in the position of the highest-order ("leftmost") one-bit in the specifiedint value.
      intintValue()
      Returns the value of thisInteger as anint.
      longlongValue()
      Returns the value of thisInteger as along after a widening primitive conversion.
      static intlowestOneBit​(int i)
      Returns anint value with at most a single one-bit, in the position of the lowest-order ("rightmost") one-bit in the specifiedint value.
      static intmax​(int a, int b)
      Returns the greater of twoint values as if by callingMath.max.
      static intmin​(int a, int b)
      Returns the smaller of twoint values as if by callingMath.min.
      static intnumberOfLeadingZeros​(int i)
      Returns the number of zero bits preceding the highest-order ("leftmost") one-bit in the two's complement binary representation of the specifiedint value.
      static intnumberOfTrailingZeros​(int i)
      Returns the number of zero bits following the lowest-order ("rightmost") one-bit in the two's complement binary representation of the specifiedint value.
      static intparseInt​(CharSequence s, int beginIndex, int endIndex, int radix)
      Parses theCharSequence argument as a signedint in the specifiedradix, beginning at the specifiedbeginIndex and extending toendIndex - 1.
      static intparseInt​(String s)
      Parses the string argument as a signed decimal integer.
      static intparseInt​(String s, int radix)
      Parses the string argument as a signed integer in the radix specified by the second argument.
      static intparseUnsignedInt​(CharSequence s, int beginIndex, int endIndex, int radix)
      Parses theCharSequence argument as an unsignedint in the specifiedradix, beginning at the specifiedbeginIndex and extending toendIndex - 1.
      static intparseUnsignedInt​(String s)
      Parses the string argument as an unsigned decimal integer.
      static intparseUnsignedInt​(String s, int radix)
      Parses the string argument as an unsigned integer in the radix specified by the second argument.
      static intremainderUnsigned​(int dividend, int 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 intreverse​(int i)
      Returns the value obtained by reversing the order of the bits in the two's complement binary representation of the specifiedint value.
      static intreverseBytes​(int i)
      Returns the value obtained by reversing the order of the bytes in the two's complement representation of the specifiedint value.
      static introtateLeft​(int i, int distance)
      Returns the value obtained by rotating the two's complement binary representation of the specifiedint value left by the specified number of bits.
      static introtateRight​(int i, int distance)
      Returns the value obtained by rotating the two's complement binary representation of the specifiedint value right by the specified number of bits.
      shortshortValue()
      Returns the value of thisInteger as ashort after a narrowing primitive conversion.
      static intsignum​(int i)
      Returns the signum function of the specifiedint value.
      static intsum​(int a, int b)
      Adds two integers together as per the + operator.
      staticStringtoBinaryString​(int i)
      Returns a string representation of the integer argument as an unsigned integer in base 2.
      staticStringtoHexString​(int i)
      Returns a string representation of the integer argument as an unsigned integer in base 16.
      staticStringtoOctalString​(int i)
      Returns a string representation of the integer argument as an unsigned integer in base 8.
      StringtoString()
      Returns aString object representing thisInteger's value.
      staticStringtoString​(int i)
      Returns aString object representing the specified integer.
      staticStringtoString​(int i, int radix)
      Returns a string representation of the first argument in the radix specified by the second argument.
      static longtoUnsignedLong​(int x)
      Converts the argument to along by an unsigned conversion.
      staticStringtoUnsignedString​(int i)
      Returns a string representation of the argument as an unsigned decimal value.
      staticStringtoUnsignedString​(int i, int radix)
      Returns a string representation of the first argument as an unsigned integer value in the radix specified by the second argument.
      staticIntegervalueOf​(int i)
      Returns anInteger instance representing the specifiedint value.
      staticIntegervalueOf​(String s)
      Returns anInteger object holding the value of the specifiedString.
      staticIntegervalueOf​(String s, int radix)
      Returns anInteger object holding the value extracted from the specifiedString when parsed with the radix given by the second argument.

    • Field Detail

      • TYPE

        public static final Class<Integer> TYPE
        TheClass instance representing the primitive typeint.
        Since:
        1.1

      • SIZE

        @Nativepublic static final int SIZE
        The number of bits used to represent anint 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 anint value in two's complement binary form.
        Since:
        1.8
        See Also:
        Constant Field Values

    • Constructor Detail

      • Integer

        @Deprecated(since="9")public Integer​(int value)
        Deprecated.
        It is rarely appropriate to use this constructor. The static factoryvalueOf(int) is generally a better choice, as it is likely to yield significantly better space and time performance.
        Constructs a newly allocatedInteger object that represents the specifiedint value.
        Parameters:
        value - the value to be represented by theInteger object.

      • Integer

        @Deprecated(since="9")public Integer​(String s)        throwsNumberFormatException
        Deprecated.
        It is rarely appropriate to use this constructor. UseparseInt(String) to convert a string to aint primitive, or usevalueOf(String) to convert a string to anInteger object.
        Constructs a newly allocatedInteger object that represents theint value indicated by theString parameter. The string is converted to anint value in exactly the manner used by theparseInt method for radix 10.
        Parameters:
        s - theString to be converted to anInteger.
        Throws:
        NumberFormatException - if theString does not contain a parsable integer.

    • Method Detail

      • toString

        public static String toString​(int i,                              int radix)
        Returns a string representation of the first argument in the radix specified by the second argument.

        If the radix is smaller thanCharacter.MIN_RADIX or larger thanCharacter.MAX_RADIX, then the radix10 is used instead.

        If the first argument is negative, the first element of the result is the ASCII minus character'-' ('\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:

        0123456789abcdefghijklmnopqrstuvwxyz
        These are'\u0030' through'\u0039' and'\u0061' through'\u007A'. Ifradix isN, then the firstN 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:
        Integer.toString(n, 16).toUpperCase()

        Parameters:
        i - an integer 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​(int 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 thanCharacter.MIN_RADIX or larger thanCharacter.MAX_RADIX, then the radix10 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 astoString.

        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(int, int)

      • toHexString

        public static String toHexString​(int i)
        Returns a string representation of the integer argument as an unsigned integer in base 16.

        The unsigned integer value is the argument plus 232 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.

        The value of the argument can be recovered from the returned strings by callingInteger.parseUnsignedInt(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:

        0123456789abcdef
        These are the characters'\u0030' through'\u0039' and'\u0061' through'\u0066'. If uppercase letters are desired, theString.toUpperCase() method may be called on the result:
        Integer.toHexString(n).toUpperCase()

        Parameters:
        i - an integer to be converted to a string.
        Returns:
        the string representation of the unsigned integer value represented by the argument in hexadecimal (base 16).
        Since:
        1.0.2
        See Also:
        parseUnsignedInt(String, int),toUnsignedString(int, int)

      • toOctalString

        public static String toOctalString​(int i)
        Returns a string representation of the integer argument as an unsigned integer in base 8.

        The unsigned integer value is the argument plus 232 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 leading0s.

        The value of the argument can be recovered from the returned strings by callingInteger.parseUnsignedInt(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:

        01234567
        These are the characters'\u0030' through'\u0037'.

        Parameters:
        i - an integer to be converted to a string.
        Returns:
        the string representation of the unsigned integer value represented by the argument in octal (base 8).
        Since:
        1.0.2
        See Also:
        parseUnsignedInt(String, int),toUnsignedString(int, int)

      • toBinaryString

        public static String toBinaryString​(int i)
        Returns a string representation of the integer argument as an unsigned integer in base 2.

        The unsigned integer value is the argument plus 232 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.

        The value of the argument can be recovered from the returned strings by callingInteger.parseUnsignedInt(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 - an integer to be converted to a string.
        Returns:
        the string representation of the unsigned integer value represented by the argument in binary (base 2).
        Since:
        1.0.2
        See Also:
        parseUnsignedInt(String, int),toUnsignedString(int, int)

      • toString

        public static String toString​(int i)
        Returns aString object representing the specified integer. The argument is converted to signed decimal representation and returned as a string, exactly as if the argument and radix 10 were given as arguments to thetoString(int, int) method.
        Parameters:
        i - an integer to be converted.
        Returns:
        a string representation of the argument in base 10.

      • toUnsignedString

        public static String toUnsignedString​(int 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 thetoUnsignedString(int, 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(int, int)

      • parseInt

        public static int parseInt​(String s,                           int radix)                    throwsNumberFormatException
        Parses the string argument as a signed integer in 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 resulting integer value is returned.

        An exception of typeNumberFormatException is thrown if any of the following situations occurs:

        • The first argument isnull 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 typeint.

        Examples:

         parseInt("0", 10) returns 0 parseInt("473", 10) returns 473 parseInt("+42", 10) returns 42 parseInt("-0", 10) returns 0 parseInt("-FF", 16) returns -255 parseInt("1100110", 2) returns 102 parseInt("2147483647", 10) returns 2147483647 parseInt("-2147483648", 10) returns -2147483648 parseInt("2147483648", 10) throws a NumberFormatException parseInt("99", 8) throws a NumberFormatException parseInt("Kona", 10) throws a NumberFormatException parseInt("Kona", 27) returns 411787

        Parameters:
        s - theString containing the integer representation to be parsed
        radix - the radix to be used while parsings.
        Returns:
        the integer represented by the string argument in the specified radix.
        Throws:
        NumberFormatException - if theString does not contain a parsableint.

      • parseInt

        public static int parseInt​(CharSequence s,                           int beginIndex,                           int endIndex,                           int radix)                    throwsNumberFormatException
        Parses theCharSequence argument as a signedint in the specifiedradix, beginning at the specifiedbeginIndex and extending toendIndex - 1.

        The method does not take steps to guard against theCharSequence being mutated while parsing.

        Parameters:
        s - theCharSequence containing theint representation to be parsed
        beginIndex - the beginning index, inclusive.
        endIndex - the ending index, exclusive.
        radix - the radix to be used while parsings.
        Returns:
        the signedint 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

      • parseInt

        public static int parseInt​(String s)                    throwsNumberFormatException
        Parses the string argument as a signed decimal integer. 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 integer value is returned, exactly as if the argument and the radix 10 were given as arguments to theparseInt(java.lang.String, int) method.
        Parameters:
        s - aString containing theint representation to be parsed
        Returns:
        the integer value represented by the argument in decimal.
        Throws:
        NumberFormatException - if the string does not contain a parsable integer.

      • parseUnsignedInt

        public static int parseUnsignedInt​(String s,                                   int radix)                            throwsNumberFormatException
        Parses the string argument as an unsigned integer in the radix specified by the second argument. An unsigned integer maps the values usually associated with negative numbers to positive numbers larger thanMAX_VALUE. 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 plus sign'+' ('\u002B'). The resulting integer value is returned.

        An exception of typeNumberFormatException is thrown if any of the following situations occurs:

        • The first argument isnull 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 plus sign'+' ('\u002B') provided that the string is longer than length 1.
        • The value represented by the string is larger than the largest unsignedint, 232-1.

        Parameters:
        s - theString containing the unsigned integer representation to be parsed
        radix - the radix to be used while parsings.
        Returns:
        the integer represented by the string argument in the specified radix.
        Throws:
        NumberFormatException - if theString does not contain a parsableint.
        Since:
        1.8

      • parseUnsignedInt

        public static int parseUnsignedInt​(CharSequence s,                                   int beginIndex,                                   int endIndex,                                   int radix)                            throwsNumberFormatException
        Parses theCharSequence argument as an unsignedint in the specifiedradix, beginning at the specifiedbeginIndex and extending toendIndex - 1.

        The method does not take steps to guard against theCharSequence being mutated while parsing.

        Parameters:
        s - theCharSequence containing the unsignedint representation to be parsed
        beginIndex - the beginning index, inclusive.
        endIndex - the ending index, exclusive.
        radix - the radix to be used while parsings.
        Returns:
        the unsignedint 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 unsignedint in the specifiedradix, or ifradix is either smaller thanCharacter.MIN_RADIX or larger thanCharacter.MAX_RADIX.
        Since:
        9

      • parseUnsignedInt

        public static int parseUnsignedInt​(String s)                            throwsNumberFormatException
        Parses the string argument as an unsigned decimal integer. 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 theparseUnsignedInt(java.lang.String, int) method.
        Parameters:
        s - aString containing the unsignedint representation to be parsed
        Returns:
        the unsigned integer value represented by the argument in decimal.
        Throws:
        NumberFormatException - if the string does not contain a parsable unsigned integer.
        Since:
        1.8

      • valueOf

        public static Integer valueOf​(String s,                              int radix)                       throwsNumberFormatException
        Returns anInteger object holding the value extracted from the specifiedString when parsed with the radix given by the second argument. 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 theparseInt(java.lang.String, int) method. The result is anInteger object that represents the integer value specified by the string.

        In other words, this method returns anInteger object equal to the value of:

        new Integer(Integer.parseInt(s, radix))

        Parameters:
        s - the string to be parsed.
        radix - the radix to be used in interpretings
        Returns:
        anInteger object holding the value represented by the string argument in the specified radix.
        Throws:
        NumberFormatException - if theString does not contain a parsableint.

      • valueOf

        public static Integer valueOf​(String s)                       throwsNumberFormatException
        Returns anInteger object holding the value of the specifiedString. The argument is interpreted as representing a signed decimal integer, exactly as if the argument were given to theparseInt(java.lang.String) method. The result is anInteger object that represents the integer value specified by the string.

        In other words, this method returns anInteger object equal to the value of:

        new Integer(Integer.parseInt(s))

        Parameters:
        s - the string to be parsed.
        Returns:
        anInteger object holding the value represented by the string argument.
        Throws:
        NumberFormatException - if the string cannot be parsed as an integer.

      • valueOf

        public static Integer valueOf​(int i)
        Returns anInteger instance representing the specifiedint value. If a newInteger instance is not required, this method should generally be used in preference to the constructorInteger(int), 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:
        i - anint value.
        Returns:
        anInteger instance representingi.
        Since:
        1.5

      • byteValue

        public byte byteValue()
        Returns the value of thisInteger as abyte after a narrowing primitive conversion.
        Overrides:
        byteValue in class Number
        Returns:
        the numeric value represented by this object after conversion to typebyte.
        SeeThe Java™ Language Specification:
        5.1.3 Narrowing Primitive Conversions

      • shortValue

        public short shortValue()
        Returns the value of thisInteger as ashort after a narrowing primitive conversion.
        Overrides:
        shortValue in class Number
        Returns:
        the numeric value represented by this object after conversion to typeshort.
        SeeThe Java™ Language Specification:
        5.1.3 Narrowing Primitive Conversions

      • intValue

        public int intValue()
        Returns the value of thisInteger as anint.
        Specified by:
        intValue in class Number
        Returns:
        the numeric value represented by this object after conversion to typeint.

      • longValue

        public long longValue()
        Returns the value of thisInteger as along after a widening primitive conversion.
        Specified by:
        longValue in class Number
        Returns:
        the numeric value represented by this object after conversion to typelong.
        See Also:
        toUnsignedLong(int)
        SeeThe Java™ Language Specification:
        5.1.2 Widening Primitive Conversions

      • floatValue

        public float floatValue()
        Returns the value of thisInteger as afloat after a widening primitive conversion.
        Specified by:
        floatValue in class Number
        Returns:
        the numeric value represented by this object after conversion to typefloat.
        SeeThe Java™ Language Specification:
        5.1.2 Widening Primitive Conversions

      • doubleValue

        public double doubleValue()
        Returns the value of thisInteger as adouble after a widening primitive conversion.
        Specified by:
        doubleValue in class Number
        Returns:
        the numeric value represented by this object after conversion to typedouble.
        SeeThe Java™ Language Specification:
        5.1.2 Widening Primitive Conversions

      • toString

        public String toString()
        Returns aString object representing thisInteger's value. The value is converted to signed decimal representation and returned as a string, exactly as if the integer value were given as an argument to thetoString(int) method.
        Overrides:
        toString in class Object
        Returns:
        a string representation of the value of this object in base 10.

      • hashCode

        public static int hashCode​(int value)
        Returns a hash code for anint value; compatible withInteger.hashCode().
        Parameters:
        value - the value to hash
        Returns:
        a hash code value for anint value.
        Since:
        1.8

      • equals

        public boolean equals​(Object obj)
        Compares this object to the specified object. The result istrue if and only if the argument is notnull and is anInteger object that contains the sameint value as this object.
        Overrides:
        equals in class Object
        Parameters:
        obj - the object to compare with.
        Returns:
        true if the objects are the same;false otherwise.
        See Also:
        Object.hashCode(),HashMap

      • getInteger

        public static Integer getInteger​(String nm)
        Determines the integer 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 theSystem.getProperty(java.lang.String) method. The string value of this property is then interpreted as an integer value using the grammar supported bydecode and anInteger object representing this value is returned.

        If there is no property with the specified name, if the specified name is empty ornull, or if the property does not have the correct numeric format, thennull is returned.

        In other words, this method returns anInteger object equal to the value of:

        getInteger(nm, null)

        Parameters:
        nm - property name.
        Returns:
        theInteger 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)

      • getInteger

        public static Integer getInteger​(String nm,                                 int val)
        Determines the integer 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 theSystem.getProperty(java.lang.String) method. The string value of this property is then interpreted as an integer value using the grammar supported bydecode and anInteger object representing this value is returned.

        The second argument is the default value. AnInteger 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 ornull.

        In other words, this method returns anInteger object equal to the value of:

        getInteger(nm, new Integer(val))
        but in practice it may be implemented in a manner such as:
         Integer result = getInteger(nm, null); return (result == null) ? new Integer(val) : result;
        to avoid the unnecessary allocation of anInteger object when the default value is not needed.

        Parameters:
        nm - property name.
        val - default value.
        Returns:
        theInteger 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)

      • getInteger

        public static Integer getInteger​(String nm,Integer val)
        Returns the integer 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 theSystem.getProperty(java.lang.String) method. The string value of this property is then interpreted as an integer value, as per thedecode method, and anInteger object representing this value is returned; in summary:
        • If the property value begins with the two ASCII characters0x or the ASCII character#, not followed by a minus sign, then the rest of it is parsed as a hexadecimal integer exactly as by the methodvalueOf(java.lang.String, int) with radix 16.
        • If the property value begins with the ASCII character0 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 methodvalueOf(java.lang.String, int) with radix 10.

        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 ornull.

        Parameters:
        nm - property name.
        val - default value.
        Returns:
        theInteger 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)

      • decode

        public static Integer decode​(String nm)                      throwsNumberFormatException
        Decodes aString into anInteger. Accepts decimal, hexadecimal, and octal numbers given by the following grammar:
        DecodableString:
        Signopt DecimalNumeral
        Signopt0xHexDigits
        Signopt0XHexDigits
        Signopt#HexDigits
        Signopt0OctalDigits
        Sign:
        -
        +
        DecimalNumeral,HexDigits, andOctalDigits are as defined in section 3.10.1 ofThe Java™ Language Specification, except that underscores are not accepted between digits.

        The sequence of characters following an optional sign and/or radix specifier ("0x", "0X", "#", or leading zero) is parsed as by the Integer.parseInt method with the indicated radix (10, 16, or 8). This sequence of characters must represent a positive value or aNumberFormatException will be thrown. The result is negated if first character of the specified String is the minus sign. No whitespace characters are permitted in theString.

        Parameters:
        nm - theString to decode.
        Returns:
        anInteger object holding theint value represented bynm
        Throws:
        NumberFormatException - if theString does not contain a parsable integer.
        See Also:
        parseInt(java.lang.String, int)

      • compareTo

        public int compareTo​(Integer anotherInteger)
        Compares twoInteger objects numerically.
        Specified by:
        compareTo in interface Comparable<Integer>
        Parameters:
        anotherInteger - theInteger to be compared.
        Returns:
        the value0 if thisInteger is equal to the argumentInteger; a value less than0 if thisInteger is numerically less than the argumentInteger; and a value greater than0 if thisInteger is numerically greater than the argumentInteger (signed comparison).
        Since:
        1.2

      • compare

        public static int compare​(int x,                          int y)
        Compares twoint values numerically. The value returned is identical to what would be returned by:
            Integer.valueOf(x).compareTo(Integer.valueOf(y))
        Parameters:
        x - the firstint to compare
        y - the secondint to compare
        Returns:
        the value0 ifx == y; a value less than0 ifx < y; and a value greater than0 ifx > y
        Since:
        1.7

      • compareUnsigned

        public static int compareUnsigned​(int x,                                  int y)
        Compares twoint values numerically treating the values as unsigned.
        Parameters:
        x - the firstint to compare
        y - the secondint to compare
        Returns:
        the value0 ifx == y; a value less than0 ifx < y as unsigned values; and a value greater than0 ifx > y as unsigned values
        Since:
        1.8

      • toUnsignedLong

        public static long toUnsignedLong​(int x)
        Converts the argument to along by an unsigned conversion. In an unsigned conversion to along, the high-order 32 bits of thelong are zero and the low-order 32 bits are equal to the bits of the integer argument. Consequently, zero and positiveint values are mapped to a numerically equallong value and negative int values are mapped to along value equal to the input plus 232.
        Parameters:
        x - the value to convert to an unsignedlong
        Returns:
        the argument converted tolong by an unsigned conversion
        Since:
        1.8

      • divideUnsigned

        public static int divideUnsigned​(int dividend,                                 int 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(int, int)

      • remainderUnsigned

        public static int remainderUnsigned​(int dividend,                                    int 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(int, int)

      • highestOneBit

        public static int highestOneBit​(int i)
        Returns anint value with at most a single one-bit, in the position of the highest-order ("leftmost") one-bit in the specifiedint 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:
        anint 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 int lowestOneBit​(int i)
        Returns anint value with at most a single one-bit, in the position of the lowest-order ("rightmost") one-bit in the specifiedint 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:
        anint 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​(int i)
        Returns the number of zero bits preceding the highest-order ("leftmost") one-bit in the two's complement binary representation of the specifiedint value. Returns 32 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 positiveint values x:

        • floor(log2(x)) =31 - numberOfLeadingZeros(x)
        • ceil(log2(x)) =32 - 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 specifiedint value, or 32 if the value is equal to zero.
        Since:
        1.5

      • numberOfTrailingZeros

        public static int numberOfTrailingZeros​(int i)
        Returns the number of zero bits following the lowest-order ("rightmost") one-bit in the two's complement binary representation of the specifiedint value. Returns 32 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 specifiedint value, or 32 if the value is equal to zero.
        Since:
        1.5

      • bitCount

        public static int bitCount​(int i)
        Returns the number of one-bits in the two's complement binary representation of the specifiedint value. This function is sometimes referred to as thepopulation 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 specifiedint value.
        Since:
        1.5

      • rotateLeft

        public static int rotateLeft​(int i,                             int distance)
        Returns the value obtained by rotating the two's complement binary representation of the specifiedint 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 32 is a no-op, so all but the last five bits of the rotation distance can be ignored, even if the distance is negative:rotateLeft(val, distance) == rotateLeft(val, distance & 0x1F).

        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 specifiedint value left by the specified number of bits.
        Since:
        1.5

      • rotateRight

        public static int rotateRight​(int i,                              int distance)
        Returns the value obtained by rotating the two's complement binary representation of the specifiedint 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 32 is a no-op, so all but the last five bits of the rotation distance can be ignored, even if the distance is negative:rotateRight(val, distance) == rotateRight(val, distance & 0x1F).

        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 specifiedint value right by the specified number of bits.
        Since:
        1.5

      • reverse

        public static int reverse​(int i)
        Returns the value obtained by reversing the order of the bits in the two's complement binary representation of the specifiedint value.
        Parameters:
        i - the value to be reversed
        Returns:
        the value obtained by reversing order of the bits in the specifiedint value.
        Since:
        1.5

      • signum

        public static int signum​(int i)
        Returns the signum function of the specifiedint 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 specifiedint value.
        Since:
        1.5

      • reverseBytes

        public static int reverseBytes​(int i)
        Returns the value obtained by reversing the order of the bytes in the two's complement representation of the specifiedint value.
        Parameters:
        i - the value whose bytes are to be reversed
        Returns:
        the value obtained by reversing the bytes in the specifiedint value.
        Since:
        1.5

      • sum

        public static int sum​(int a,                      int b)
        Adds two integers together as per the + operator.
        Parameters:
        a - the first operand
        b - the second operand
        Returns:
        the sum ofa andb
        Since:
        1.8
        See Also:
        BinaryOperator

      • max

        public static int max​(int a,                      int b)
        Returns the greater of twoint values as if by callingMath.max.
        Parameters:
        a - the first operand
        b - the second operand
        Returns:
        the greater ofa andb
        Since:
        1.8
        See Also:
        BinaryOperator

      • min

        public static int min​(int a,                      int b)
        Returns the smaller of twoint values as if by callingMath.min.
        Parameters:
        a - the first operand
        b - the second operand
        Returns:
        the smaller ofa andb
        Since:
        1.8
        See Also:
        BinaryOperator