Added in API level 34

HexFormat

public final class HexFormat
extends Object

java.lang.Object
   ↳ java.util.HexFormat


HexFormat converts between bytes and chars and hex-encoded strings which may include additional formatting markup such as prefixes, suffixes, and delimiters.

There are two factories of HexFormat with preset parameters of() and ofDelimiter(delimiter). For other parameter combinations the withXXX methods return copies of HexFormat modified withPrefix(java.lang.String), withSuffix(java.lang.String), withDelimiter(java.lang.String) or choice of withUpperCase() or withLowerCase() parameters.

For primitive to hexadecimal string conversions the toHexDigits methods include toHexDigits(byte), toHexDigits(int), and toHexDigits(long), etc. The default is to use lowercase characters "0-9","a-f". For conversions producing uppercase hexadecimal the characters are "0-9","A-F". Only the HexFormat.isUpperCase() parameter is considered; the delimiter, prefix and suffix are not used.

For hexadecimal string to primitive conversions the fromHexDigits methods include fromHexDigits(string), fromHexDigitsToLong(string), and fromHexDigit(int) converts a single character or codepoint. For conversions from hexadecimal characters the digits and uppercase and lowercase characters in "0-9", "a-f", and "A-F" are converted to corresponding values 0-15. The delimiter, prefix, suffix, and uppercase parameters are not used.

For byte array to formatted hexadecimal string conversions the formatHex methods include formatHex(byte[]) and formatHex(Appendable, byte[]). The formatted output is a string or is appended to an Appendable such as StringBuilder or PrintStream. Each byte value is formatted as the prefix, two hexadecimal characters from the uppercase or lowercase digits, and the suffix. A delimiter follows each formatted value, except the last. For conversions producing uppercase hexadecimal strings use withUpperCase().

For formatted hexadecimal string to byte array conversions the parseHex methods include parseHex(CharSequence) and parseHex(char[], offset, length). Each byte value is parsed from the prefix, two case insensitive hexadecimal characters, and the suffix. A delimiter follows each formatted value, except the last.

Summary

Public methods

String delimiter()

Returns the delimiter between hexadecimal values in formatted hexadecimal strings.

boolean equals(Object o)

Returns true if the other object is a HexFormat with the same parameters.

<A extends Appendable> A formatHex(A out, byte[] bytes)

Appends formatted hexadecimal strings from a byte array to the Appendable.

String formatHex(byte[] bytes)

Returns a hexadecimal string formatted from a byte array.

String formatHex(byte[] bytes, int fromIndex, int toIndex)

Returns a hexadecimal string formatted from a byte array range.

<A extends Appendable> A formatHex(A out, byte[] bytes, int fromIndex, int toIndex)

Appends formatted hexadecimal strings from a byte array range to the Appendable.

static int fromHexDigit(int ch)

Returns the value for the hexadecimal character or codepoint.

static int fromHexDigits(CharSequence string, int fromIndex, int toIndex)

Returns the int value parsed from a string range of up to eight hexadecimal characters.

static int fromHexDigits(CharSequence string)

Returns the int value parsed from a string of up to eight hexadecimal characters.

static long fromHexDigitsToLong(CharSequence string, int fromIndex, int toIndex)

Returns the long value parsed from a string range of up to sixteen hexadecimal characters.

static long fromHexDigitsToLong(CharSequence string)

Returns the long value parsed from a string of up to sixteen hexadecimal characters.

int hashCode()

Returns a hashcode for this HexFormat.

static boolean isHexDigit(int ch)

Returns true if the character is a valid hexadecimal character or codepoint.

boolean isUpperCase()

Returns true if the hexadecimal digits are uppercase, otherwise false.

static HexFormat of()

Returns a hexadecimal formatter with no delimiter and lowercase characters.

static HexFormat ofDelimiter(String delimiter)

Returns a hexadecimal formatter with the delimiter and lowercase characters.

byte[] parseHex(CharSequence string)

Returns a byte array containing hexadecimal values parsed from the string.

byte[] parseHex(CharSequence string, int fromIndex, int toIndex)

Returns a byte array containing hexadecimal values parsed from a range of the string.

byte[] parseHex(char[] chars, int fromIndex, int toIndex)

Returns a byte array containing hexadecimal values parsed from a range of the character array.

String prefix()

Returns the prefix used for each hexadecimal value in formatted hexadecimal strings.

String suffix()

Returns the suffix used for each hexadecimal value in formatted hexadecimal strings.

String toHexDigits(short value)

Returns the four hexadecimal characters for the short value.

String toHexDigits(byte value)

Returns the two hexadecimal characters for the byte value.

String toHexDigits(int value)

Returns the eight hexadecimal characters for the int value.

String toHexDigits(char value)

Returns the four hexadecimal characters for the char value.

<A extends Appendable> A toHexDigits(A out, byte value)

Appends two hexadecimal characters for the byte value to the Appendable.

String toHexDigits(long value, int digits)

Returns up to sixteen hexadecimal characters for the long value.

String toHexDigits(long value)

Returns the sixteen hexadecimal characters for the long value.

char toHighHexDigit(int value)

Returns the hexadecimal character for the high 4 bits of the value considering it to be a byte.

char toLowHexDigit(int value)

Returns the hexadecimal character for the low 4 bits of the value considering it to be a byte.

String toString()

Returns a description of the formatter parameters for uppercase, delimiter, prefix, and suffix.

HexFormat withDelimiter(String delimiter)

Returns a copy of this HexFormat with the delimiter.

HexFormat withLowerCase()

Returns a copy of this HexFormat to use lowercase hexadecimal characters.

HexFormat withPrefix(String prefix)

Returns a copy of this HexFormat with the prefix.

HexFormat withSuffix(String suffix)

Returns a copy of this HexFormat with the suffix.

HexFormat withUpperCase()

Returns a copy of this HexFormat to use uppercase hexadecimal characters.

Inherited methods

Public methods

delimiter

Added in API level 34
public String delimiter ()

Returns the delimiter between hexadecimal values in formatted hexadecimal strings.

Returns
String the delimiter, non-null, may be empty ""

equals

Added in API level 34
public boolean equals (Object o)

Returns true if the other object is a HexFormat with the same parameters.

Parameters
o Object: an object, may be null

Returns
boolean true if the other object is a HexFormat and the parameters uppercase, delimiter, prefix, and suffix are equal; otherwise false

formatHex

Added in API level 34
public A formatHex (A out, 
                byte[] bytes)

Appends formatted hexadecimal strings from a byte array to the Appendable. Each byte value is formatted as the prefix, two hexadecimal characters selected from uppercase or lowercase digits, and the suffix. A delimiter follows each formatted value, except the last. The formatted hexadecimal strings are appended in zero or more calls to the Appendable methods.

Parameters
out A: an Appendable, non-null

bytes byte: a byte array

Returns
A the Appendable

Throws
UncheckedIOException if an I/O exception occurs appending to the output

formatHex

Added in API level 34
public String formatHex (byte[] bytes)

Returns a hexadecimal string formatted from a byte array. Each byte value is formatted as the prefix, two hexadecimal characters selected from uppercase or lowercase digits, and the suffix. A delimiter follows each formatted value, except the last. The behavior is equivalent to formatHex(bytes, 0, bytes.length)).

Parameters
bytes byte: a non-null array of bytes

Returns
String a string hexadecimal formatting of the byte array

formatHex

Added in API level 34
public String formatHex (byte[] bytes, 
                int fromIndex, 
                int toIndex)

Returns a hexadecimal string formatted from a byte array range. Each byte value is formatted as the prefix, two hexadecimal characters selected from uppercase or lowercase digits, and the suffix. A delimiter follows each formatted value, except the last.

Parameters
bytes byte: a non-null array of bytes

fromIndex int: the initial index of the range, inclusive

toIndex int: the final index of the range, exclusive

Returns
String a string hexadecimal formatting each byte of the array range

Throws
IndexOutOfBoundsException if the array range is out of bounds

formatHex

Added in API level 34
public A formatHex (A out, 
                byte[] bytes, 
                int fromIndex, 
                int toIndex)

Appends formatted hexadecimal strings from a byte array range to the Appendable. Each byte value is formatted as the prefix, two hexadecimal characters selected from uppercase or lowercase digits, and the suffix. A delimiter follows each formatted value, except the last. The formatted hexadecimal strings are appended in zero or more calls to the Appendable methods.

Parameters
out A: an Appendable, non-null

bytes byte: a byte array, non-null

fromIndex int: the initial index of the range, inclusive

toIndex int: the final index of the range, exclusive.

Returns
A the Appendable

Throws
IndexOutOfBoundsException if the array range is out of bounds
UncheckedIOException if an I/O exception occurs appending to the output

fromHexDigit

Added in API level 34
public static int fromHexDigit (int ch)

Returns the value for the hexadecimal character or codepoint. The value is:

  • (ch - '0') for '0' through '9' inclusive,
  • (ch - 'A' + 10) for 'A' through 'F' inclusive, and
  • (ch - 'a' + 10) for 'a' through 'f' inclusive.

Parameters
ch int: a character or codepoint

Returns
int the value 0-15

Throws
NumberFormatException if the codepoint is not a hexadecimal character

fromHexDigits

Added in API level 34
public static int fromHexDigits (CharSequence string, 
                int fromIndex, 
                int toIndex)

Returns the int value parsed from a string range of up to eight hexadecimal characters. The characters in the range fromIndex to toIndex, exclusive, are parsed from most significant to least significant using fromHexDigit(int) to form an unsigned value. The value is zero extended to 32 bits and is returned as an int.

API Note:
Parameters
string CharSequence: a CharSequence containing the characters

fromIndex int: the initial index of the range, inclusive

toIndex int: the final index of the range, exclusive.

Returns
int the value parsed from the string range

Throws
IndexOutOfBoundsException if the range is out of bounds for the CharSequence
IllegalArgumentException if length of the range is greater than eight (8) or if any of the characters is not a hexadecimal character

fromHexDigits

Added in API level 34
public static int fromHexDigits (CharSequence string)

Returns the int value parsed from a string of up to eight hexadecimal characters. The hexadecimal characters are parsed from most significant to least significant using fromHexDigit(int) to form an unsigned value. The value is zero extended to 32 bits and is returned as an int.

API Note:
Parameters
string CharSequence: a CharSequence containing up to eight hexadecimal characters

Returns
int the value parsed from the string

Throws
IllegalArgumentException if the string length is greater than eight (8) or if any of the characters is not a hexadecimal character

fromHexDigitsToLong

Added in API level 34
public static long fromHexDigitsToLong (CharSequence string, 
                int fromIndex, 
                int toIndex)

Returns the long value parsed from a string range of up to sixteen hexadecimal characters. The characters in the range fromIndex to toIndex, exclusive, are parsed from most significant to least significant using fromHexDigit(int) to form an unsigned value. The value is zero extended to 64 bits and is returned as a long.

API Note:
Parameters
string CharSequence: a CharSequence containing the characters

fromIndex int: the initial index of the range, inclusive

toIndex int: the final index of the range, exclusive.

Returns
long the value parsed from the string range

Throws
IndexOutOfBoundsException if the range is out of bounds for the CharSequence
IllegalArgumentException if the length of the range is greater than sixteen (16) or if any of the characters is not a hexadecimal character

fromHexDigitsToLong

Added in API level 34
public static long fromHexDigitsToLong (CharSequence string)

Returns the long value parsed from a string of up to sixteen hexadecimal characters. The hexadecimal characters are parsed from most significant to least significant using fromHexDigit(int) to form an unsigned value. The value is zero extended to 64 bits and is returned as a long.

API Note:
Parameters
string CharSequence: a CharSequence containing up to sixteen hexadecimal characters

Returns
long the value parsed from the string

Throws
IllegalArgumentException if the string length is greater than sixteen (16) or if any of the characters is not a hexadecimal character

hashCode

Added in API level 34
public int hashCode ()

Returns a hashcode for this HexFormat.

Returns
int a hashcode for this HexFormat

isHexDigit

Added in API level 34
public static boolean isHexDigit (int ch)

Returns true if the character is a valid hexadecimal character or codepoint. The valid hexadecimal characters are:

  • '0' ('\u0030') through '9' ('\u0039') inclusive,
  • 'A' ('\u0041') through 'F' ('\u0046') inclusive, and
  • 'a' ('\u0061') through 'f' ('\u0066') inclusive.

Parameters
ch int: a codepoint

Returns
boolean true if the character is valid a hexadecimal character, otherwise false

isUpperCase

Added in API level 34
public boolean isUpperCase ()

Returns true if the hexadecimal digits are uppercase, otherwise false.

Returns
boolean true if the hexadecimal digits are uppercase, otherwise false

of

Added in API level 34
public static HexFormat of ()

Returns a hexadecimal formatter with no delimiter and lowercase characters. The delimiter, prefix, and suffix are empty. The methods withDelimiter, withUpperCase, withLowerCase, withPrefix, and withSuffix return copies of formatters with new parameters.

Returns
HexFormat a hexadecimal formatter with no delimiter and lowercase characters

ofDelimiter

Added in API level 34
public static HexFormat ofDelimiter (String delimiter)

Returns a hexadecimal formatter with the delimiter and lowercase characters. The prefix and suffix are empty. The methods withDelimiter, withUpperCase, withLowerCase, withPrefix, and withSuffix return copies of formatters with new parameters.

Parameters
delimiter String: a delimiter, non-null, may be empty

Returns
HexFormat a HexFormat with the delimiter and lowercase characters

parseHex

Added in API level 34
public byte[] parseHex (CharSequence string)

Returns a byte array containing hexadecimal values parsed from the string. Each byte value is parsed from the prefix, two case insensitive hexadecimal characters, and the suffix. A delimiter follows each formatted value, except the last. The delimiters, prefixes, and suffixes strings must be present; they may be empty strings. A valid string consists only of the above format.

Parameters
string CharSequence: a string containing the byte values with prefix, hexadecimal digits, suffix, and delimiters

Returns
byte[] a byte array with the values parsed from the string

Throws
IllegalArgumentException if the prefix or suffix is not present for each byte value, the byte values are not hexadecimal characters, or if the delimiter is not present after all but the last byte value

parseHex

Added in API level 34
public byte[] parseHex (CharSequence string, 
                int fromIndex, 
                int toIndex)

Returns a byte array containing hexadecimal values parsed from a range of the string. Each byte value is parsed from the prefix, two case insensitive hexadecimal characters, and the suffix. A delimiter follows each formatted value, except the last. The delimiters, prefixes, and suffixes strings must be present; they may be empty strings. A valid string consists only of the above format.

Parameters
string CharSequence: a string range containing hexadecimal digits, delimiters, prefix, and suffix.

fromIndex int: the initial index of the range, inclusive

toIndex int: the final index of the range, exclusive.

Returns
byte[] a byte array with the values parsed from the string range

Throws
IllegalArgumentException if the prefix or suffix is not present for each byte value, the byte values are not hexadecimal characters, or if the delimiter is not present after all but the last byte value
IndexOutOfBoundsException if the string range is out of bounds

parseHex

Added in API level 34
public byte[] parseHex (char[] chars, 
                int fromIndex, 
                int toIndex)

Returns a byte array containing hexadecimal values parsed from a range of the character array. Each byte value is parsed from the prefix, two case insensitive hexadecimal characters, and the suffix. A delimiter follows each formatted value, except the last. The delimiters, prefixes, and suffixes strings must be present; they may be empty strings. A valid character array range consists only of the above format.

Parameters
chars char: a character array range containing an even number of hexadecimal digits, delimiters, prefix, and suffix.

fromIndex int: the initial index of the range, inclusive

toIndex int: the final index of the range, exclusive.

Returns
byte[] a byte array with the values parsed from the character array range

Throws
IllegalArgumentException if the prefix or suffix is not present for each byte value, the byte values are not hexadecimal characters, or if the delimiter is not present after all but the last byte value
IndexOutOfBoundsException if the character array range is out of bounds

prefix

Added in API level 34
public String prefix ()

Returns the prefix used for each hexadecimal value in formatted hexadecimal strings.

Returns
String the prefix, non-null, may be empty ""

suffix

Added in API level 34
public String suffix ()

Returns the suffix used for each hexadecimal value in formatted hexadecimal strings.

Returns
String the suffix, non-null, may be empty ""

toHexDigits

Added in API level 34
public String toHexDigits (short value)

Returns the four hexadecimal characters for the short value. Each nibble (4 bits) from most significant to least significant of the value is formatted as if by toLowHexDigit(nibble). The delimiter, prefix and suffix are not used.

Parameters
value short: a short value

Returns
String the four hexadecimal characters for the short value

toHexDigits

Added in API level 34
public String toHexDigits (byte value)

Returns the two hexadecimal characters for the byte value. Each nibble (4 bits) from most significant to least significant of the value is formatted as if by toLowHexDigit(nibble). The delimiter, prefix and suffix are not used.

Parameters
value byte: a byte value

Returns
String the two hexadecimal characters for the byte value

toHexDigits

Added in API level 34
public String toHexDigits (int value)

Returns the eight hexadecimal characters for the int value. Each nibble (4 bits) from most significant to least significant of the value is formatted as if by toLowHexDigit(nibble). The delimiter, prefix and suffix are not used.

Parameters
value int: an int value

Returns
String the eight hexadecimal characters for the int value

toHexDigits

Added in API level 34
public String toHexDigits (char value)

Returns the four hexadecimal characters for the char value. Each nibble (4 bits) from most significant to least significant of the value is formatted as if by toLowHexDigit(nibble). The delimiter, prefix and suffix are not used.

Parameters
value char: a char value

Returns
String the four hexadecimal characters for the char value

toHexDigits

Added in API level 34
public A toHexDigits (A out, 
                byte value)

Appends two hexadecimal characters for the byte value to the Appendable. Each nibble (4 bits) from most significant to least significant of the value is formatted as if by toLowHexDigit(nibble). The hexadecimal characters are appended in one or more calls to the Appendable methods. The delimiter, prefix and suffix are not used.

Parameters
out A: an Appendable, non-null

value byte: a byte value

Returns
A the Appendable

Throws
UncheckedIOException if an I/O exception occurs appending to the output

toHexDigits

Added in API level 34
public String toHexDigits (long value, 
                int digits)

Returns up to sixteen hexadecimal characters for the long value. Each nibble (4 bits) from most significant to least significant of the value is formatted as if by toLowHexDigit(nibble). The delimiter, prefix and suffix are not used.

Parameters
value long: a long value

digits int: the number of hexadecimal digits to return, 0 to 16

Returns
String the hexadecimal characters for the long value

Throws
IllegalArgumentException if digits is negative or greater than 16

toHexDigits

Added in API level 34
public String toHexDigits (long value)

Returns the sixteen hexadecimal characters for the long value. Each nibble (4 bits) from most significant to least significant of the value is formatted as if by toLowHexDigit(nibble). The delimiter, prefix and suffix are not used.

Parameters
value long: a long value

Returns
String the sixteen hexadecimal characters for the long value

toHighHexDigit

Added in API level 34
public char toHighHexDigit (int value)

Returns the hexadecimal character for the high 4 bits of the value considering it to be a byte. If the parameter isUpperCase() is true the character returned for values 10-15 is uppercase "A-F", otherwise the character returned is lowercase "a-f". The values in the range 0-9 are returned as "0-9".

Parameters
value int: a value, only bits 4-7 of the value are used

Returns
char the hexadecimal character for the bits 4-7 of the value

toLowHexDigit

Added in API level 34
public char toLowHexDigit (int value)

Returns the hexadecimal character for the low 4 bits of the value considering it to be a byte. If the parameter isUpperCase() is true the character returned for values 10-15 is uppercase "A-F", otherwise the character returned is lowercase "a-f". The values in the range 0-9 are returned as "0-9".

Parameters
value int: a value, only the low 4 bits 0-3 of the value are used

Returns
char the hexadecimal character for the low 4 bits 0-3 of the value

toString

Added in API level 34
public String toString ()

Returns a description of the formatter parameters for uppercase, delimiter, prefix, and suffix.

Returns
String a description of this HexFormat

withDelimiter

Added in API level 34
public HexFormat withDelimiter (String delimiter)

Returns a copy of this HexFormat with the delimiter.

Parameters
delimiter String: the delimiter, non-null, may be empty

Returns
HexFormat a copy of this HexFormat with the delimiter

withLowerCase

Added in API level 34
public HexFormat withLowerCase ()

Returns a copy of this HexFormat to use lowercase hexadecimal characters. The lowercase hexadecimal characters are "0-9", "a-f".

Returns
HexFormat a copy of this HexFormat with lowercase hexadecimal characters

withPrefix

Added in API level 34
public HexFormat withPrefix (String prefix)

Returns a copy of this HexFormat with the prefix.

Parameters
prefix String: a prefix, non-null, may be empty

Returns
HexFormat a copy of this HexFormat with the prefix

withSuffix

Added in API level 34
public HexFormat withSuffix (String suffix)

Returns a copy of this HexFormat with the suffix.

Parameters
suffix String: a suffix, non-null, may be empty

Returns
HexFormat a copy of this HexFormat with the suffix

withUpperCase

Added in API level 34
public HexFormat withUpperCase ()

Returns a copy of this HexFormat to use uppercase hexadecimal characters. The uppercase hexadecimal characters are "0-9", "A-F".

Returns
HexFormat a copy of this HexFormat with uppercase hexadecimal characters