Package org.apache.commons.codec.binary

Class Hex

java.lang.Object

org.apache.commons.codec.binary.Hex

All Implemented Interfaces:

BinaryDecoder, BinaryEncoder, Decoder, Encoder

public class Hex
extends java.lang.Object
implements BinaryEncoder, BinaryDecoder

Converts hexadecimal Strings. The Charset used for certain operation can be set, the default is set in DEFAULT_CHARSET_NAME This class is thread-safe.

Since:

1.1

Field Summary

Fields

Modifier and Type	Field	Description
static java.nio.charset.Charset	DEFAULT_CHARSET	Default charset is StandardCharsets.UTF_8.
static java.lang.String	DEFAULT_CHARSET_NAME	Default charset name is CharEncoding.UTF_8.

Constructor Summary

Constructors

Constructor	Description
Hex()	Creates a new codec with the default charset name DEFAULT_CHARSET
Hex(java.lang.String charsetName)	Creates a new codec with the given charset name.
Hex(java.nio.charset.Charset charset)	Creates a new codec with the given Charset.

Method Summary

Modifier and Type	Method	Description
byte[]	decode(byte[] array)	Converts an array of character bytes representing hexadecimal values into an array of bytes of those same values.
java.lang.Object	decode(java.lang.Object object)	Converts a String or an array of character bytes representing hexadecimal values into an array of bytes of those same values.
byte[]	decode(java.nio.ByteBuffer buffer)	Converts a buffer of character bytes representing hexadecimal values into an array of bytes of those same values.
static byte[]	decodeHex(char[] data)	Converts an array of characters representing hexadecimal values into an array of bytes of those same values.
static int	decodeHex(char[] data, byte[] out, int outOffset)	Converts an array of characters representing hexadecimal values into an array of bytes of those same values.
static byte[]	decodeHex(java.lang.String data)	Converts a String representing hexadecimal values into an array of bytes of those same values.
byte[]	encode(byte[] array)	Converts an array of bytes into an array of bytes for the characters representing the hexadecimal values of each byte in order.
java.lang.Object	encode(java.lang.Object object)	Converts a String or an array of bytes into an array of characters representing the hexadecimal values of each byte in order.
byte[]	encode(java.nio.ByteBuffer array)	Converts byte buffer into an array of bytes for the characters representing the hexadecimal values of each byte in order.
static char[]	encodeHex(byte[] data)	Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order.
static char[]	encodeHex(byte[] data, boolean toLowerCase)	Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order.
protected static char[]	encodeHex(byte[] data, char[] toDigits)	Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order.
static char[]	encodeHex(byte[] data, int dataOffset, int dataLen, boolean toLowerCase)	Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order.
static void	encodeHex(byte[] data, int dataOffset, int dataLen, boolean toLowerCase, char[] out, int outOffset)	Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order.
static char[]	encodeHex(java.nio.ByteBuffer data)	Converts a byte buffer into an array of characters representing the hexadecimal values of each byte in order.
static char[]	encodeHex(java.nio.ByteBuffer data, boolean toLowerCase)	Converts a byte buffer into an array of characters representing the hexadecimal values of each byte in order.
protected static char[]	encodeHex(java.nio.ByteBuffer byteBuffer, char[] toDigits)	Converts a byte buffer into an array of characters representing the hexadecimal values of each byte in order.
static java.lang.String	encodeHexString(byte[] data)	Converts an array of bytes into a String representing the hexadecimal values of each byte in order.
static java.lang.String	encodeHexString(byte[] data, boolean toLowerCase)	Converts an array of bytes into a String representing the hexadecimal values of each byte in order.
static java.lang.String	encodeHexString(java.nio.ByteBuffer data)	Converts a byte buffer into a String representing the hexadecimal values of each byte in order.
static java.lang.String	encodeHexString(java.nio.ByteBuffer data, boolean toLowerCase)	Converts a byte buffer into a String representing the hexadecimal values of each byte in order.
java.nio.charset.Charset	getCharset()	Gets the charset.
java.lang.String	getCharsetName()	Gets the charset name.
protected static int	toDigit(char ch, int index)	Converts a hexadecimal character to an integer.
java.lang.String	toString()	Returns a string representation of the object, which includes the charset name.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

DEFAULT_CHARSET

public static final java.nio.charset.Charset DEFAULT_CHARSET

Default charset is StandardCharsets.UTF_8.

Since:

1.7

DEFAULT_CHARSET_NAME

public static final java.lang.String DEFAULT_CHARSET_NAME

Default charset name is CharEncoding.UTF_8.

Since:

1.4

See Also:

Constant Field Values

Constructor Detail

Hex

public Hex()

Creates a new codec with the default charset name DEFAULT_CHARSET

Hex

public Hex(java.nio.charset.Charset charset)

Creates a new codec with the given Charset.

Parameters:

charset - the charset.

Since:

1.7

Hex

public Hex(java.lang.String charsetName)

Creates a new codec with the given charset name.

Parameters:

charsetName - the charset name.

Throws:

java.nio.charset.UnsupportedCharsetException - If the named charset is unavailable

Since:

1.4, 1.7 throws UnsupportedCharsetException if the named charset is unavailable

Method Detail

decodeHex

public static byte[] decodeHex(char[] data)
                        throws DecoderException

Converts an array of characters representing hexadecimal values into an array of bytes of those same values. The returned array will be half the length of the passed array, as it takes two characters to represent any given byte. An exception is thrown if the passed char array has an odd number of elements.

Parameters:

data - An array of characters containing hexadecimal digits

Returns:

A byte array containing binary data decoded from the supplied char array.

Throws:

DecoderException - Thrown if an odd number of characters or illegal characters are supplied

decodeHex

public static int decodeHex(char[] data,
                            byte[] out,
                            int outOffset)
                     throws DecoderException

Converts an array of characters representing hexadecimal values into an array of bytes of those same values. The returned array will be half the length of the passed array, as it takes two characters to represent any given byte. An exception is thrown if the passed char array has an odd number of elements.

Parameters:

data - An array of characters containing hexadecimal digits

out - A byte array to contain the binary data decoded from the supplied char array.

outOffset - The position within out to start writing the decoded bytes.

Returns:

the number of bytes written to out.

Throws:

DecoderException - Thrown if an odd number of characters or illegal characters are supplied

Since:

1.15

decodeHex

public static byte[] decodeHex(java.lang.String data)
                        throws DecoderException

Converts a String representing hexadecimal values into an array of bytes of those same values. The returned array will be half the length of the passed String, as it takes two characters to represent any given byte. An exception is thrown if the passed String has an odd number of elements.

Parameters:

data - A String containing hexadecimal digits

Returns:

A byte array containing binary data decoded from the supplied char array.

Throws:

DecoderException - Thrown if an odd number of characters or illegal characters are supplied

Since:

1.11

encodeHex

public static char[] encodeHex(byte[] data)

Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order. The returned array will be double the length of the passed array, as it takes two characters to represent any given byte.

Parameters:

data - a byte[] to convert to hex characters

Returns:

A char[] containing lower-case hexadecimal characters

encodeHex

public static char[] encodeHex(byte[] data,
                               boolean toLowerCase)

Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order. The returned array will be double the length of the passed array, as it takes two characters to represent any given byte.

Parameters:

data - a byte[] to convert to Hex characters

toLowerCase - true converts to lowercase, false to uppercase

Returns:

A char[] containing hexadecimal characters in the selected case

Since:

1.4

encodeHex

protected static char[] encodeHex(byte[] data,
                                  char[] toDigits)

Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order. The returned array will be double the length of the passed array, as it takes two characters to represent any given byte.

Parameters:

data - a byte[] to convert to hex characters

toDigits - the output alphabet (must contain at least 16 chars)

Returns:

A char[] containing the appropriate characters from the alphabet For best results, this should be either upper- or lower-case hex.

Since:

1.4

encodeHex

public static char[] encodeHex(byte[] data,
                               int dataOffset,
                               int dataLen,
                               boolean toLowerCase)

Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order.

Parameters:

data - a byte[] to convert to hex characters

dataOffset - the position in data to start encoding from

dataLen - the number of bytes from dataOffset to encode

toLowerCase - true converts to lowercase, false to uppercase

Returns:

A char[] containing the appropriate characters from the alphabet For best results, this should be either upper- or lower-case hex.

Since:

1.15

encodeHex

public static void encodeHex(byte[] data,
                             int dataOffset,
                             int dataLen,
                             boolean toLowerCase,
                             char[] out,
                             int outOffset)

Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order.

Parameters:

data - a byte[] to convert to hex characters

dataOffset - the position in data to start encoding from

dataLen - the number of bytes from dataOffset to encode

toLowerCase - true converts to lowercase, false to uppercase

out - a char[] which will hold the resultant appropriate characters from the alphabet.

outOffset - the position within out at which to start writing the encoded characters.

Since:

1.15

encodeHex

public static char[] encodeHex(java.nio.ByteBuffer data)

Converts a byte buffer into an array of characters representing the hexadecimal values of each byte in order. The returned array will be double the length of the passed array, as it takes two characters to represent any given byte.

All bytes identified by Buffer.remaining() will be used; after this method the value remaining() will be zero.

Parameters:

data - a byte buffer to convert to hex characters

Returns:

A char[] containing lower-case hexadecimal characters

Since:

1.11

encodeHex

public static char[] encodeHex(java.nio.ByteBuffer data,
                               boolean toLowerCase)

Converts a byte buffer into an array of characters representing the hexadecimal values of each byte in order. The returned array will be double the length of the passed array, as it takes two characters to represent any given byte.

All bytes identified by Buffer.remaining() will be used; after this method the value remaining() will be zero.

Parameters:

data - a byte buffer to convert to hex characters

toLowerCase - true converts to lowercase, false to uppercase

Returns:

A char[] containing hexadecimal characters in the selected case

Since:

1.11

encodeHex

protected static char[] encodeHex(java.nio.ByteBuffer byteBuffer,
                                  char[] toDigits)

Converts a byte buffer into an array of characters representing the hexadecimal values of each byte in order. The returned array will be double the length of the passed array, as it takes two characters to represent any given byte.

All bytes identified by Buffer.remaining() will be used; after this method the value remaining() will be zero.

Parameters:

byteBuffer - a byte buffer to convert to hex characters

toDigits - the output alphabet (must be at least 16 characters)

Returns:

A char[] containing the appropriate characters from the alphabet For best results, this should be either upper- or lower-case hex.

Since:

1.11

encodeHexString

public static java.lang.String encodeHexString(byte[] data)

Converts an array of bytes into a String representing the hexadecimal values of each byte in order. The returned String will be double the length of the passed array, as it takes two characters to represent any given byte.

Parameters:

data - a byte[] to convert to hex characters

Returns:

A String containing lower-case hexadecimal characters

Since:

1.4

encodeHexString

public static java.lang.String encodeHexString(byte[] data,
                                               boolean toLowerCase)

Converts an array of bytes into a String representing the hexadecimal values of each byte in order. The returned String will be double the length of the passed array, as it takes two characters to represent any given byte.

Parameters:

data - a byte[] to convert to hex characters

toLowerCase - true converts to lowercase, false to uppercase

Returns:

A String containing lower-case hexadecimal characters

Since:

1.11

encodeHexString

public static java.lang.String encodeHexString(java.nio.ByteBuffer data)

Converts a byte buffer into a String representing the hexadecimal values of each byte in order. The returned String will be double the length of the passed array, as it takes two characters to represent any given byte.

All bytes identified by Buffer.remaining() will be used; after this method the value remaining() will be zero.

Parameters:

data - a byte buffer to convert to hex characters

Returns:

A String containing lower-case hexadecimal characters

Since:

1.11

encodeHexString

public static java.lang.String encodeHexString(java.nio.ByteBuffer data,
                                               boolean toLowerCase)

Converts a byte buffer into a String representing the hexadecimal values of each byte in order. The returned String will be double the length of the passed array, as it takes two characters to represent any given byte.

All bytes identified by Buffer.remaining() will be used; after this method the value remaining() will be zero.

Parameters:

data - a byte buffer to convert to hex characters

toLowerCase - true converts to lowercase, false to uppercase

Returns:

A String containing lower-case hexadecimal characters

Since:

1.11

toDigit

protected static int toDigit(char ch,
                             int index)
                      throws DecoderException

Converts a hexadecimal character to an integer.

Parameters:

ch - A character to convert to an integer digit

index - The index of the character in the source

Returns:

An integer

Throws:

DecoderException - Thrown if ch is an illegal hex character

decode

public byte[] decode(byte[] array)
              throws DecoderException

Converts an array of character bytes representing hexadecimal values into an array of bytes of those same values. The returned array will be half the length of the passed array, as it takes two characters to represent any given byte. An exception is thrown if the passed char array has an odd number of elements.

Specified by:

decode in interface BinaryDecoder

Parameters:

array - An array of character bytes containing hexadecimal digits

Returns:

A byte array containing binary data decoded from the supplied byte array (representing characters).

Throws:

DecoderException - Thrown if an odd number of characters is supplied to this function

See Also:

decodeHex(char[])

decode

public byte[] decode(java.nio.ByteBuffer buffer)
              throws DecoderException

Converts a buffer of character bytes representing hexadecimal values into an array of bytes of those same values. The returned array will be half the length of the passed array, as it takes two characters to represent any given byte. An exception is thrown if the passed char array has an odd number of elements.

All bytes identified by Buffer.remaining() will be used; after this method the value remaining() will be zero.

Parameters:

buffer - An array of character bytes containing hexadecimal digits

Returns:

A byte array containing binary data decoded from the supplied byte array (representing characters).

Throws:

DecoderException - Thrown if an odd number of characters is supplied to this function

Since:

1.11

See Also:

decodeHex(char[])

decode

public java.lang.Object decode(java.lang.Object object)
                        throws DecoderException

Converts a String or an array of character bytes representing hexadecimal values into an array of bytes of those same values. The returned array will be half the length of the passed String or array, as it takes two characters to represent any given byte. An exception is thrown if the passed char array has an odd number of elements.

Specified by:

decode in interface Decoder

Parameters:

object - A String, ByteBuffer, byte[], or an array of character bytes containing hexadecimal digits

Returns:

A byte array containing binary data decoded from the supplied byte array (representing characters).

Throws:

DecoderException - Thrown if an odd number of characters is supplied to this function or the object is not a String or char[]

See Also:

decodeHex(char[])

encode

public byte[] encode(byte[] array)

Converts an array of bytes into an array of bytes for the characters representing the hexadecimal values of each byte in order. The returned array will be double the length of the passed array, as it takes two characters to represent any given byte.

The conversion from hexadecimal characters to the returned bytes is performed with the charset named by getCharset().

Specified by:

encode in interface BinaryEncoder

Parameters:

array - a byte[] to convert to hex characters

Returns:

A byte[] containing the bytes of the lower-case hexadecimal characters

Since:

1.7 No longer throws IllegalStateException if the charsetName is invalid.

See Also:

encodeHex(byte[])

encode

public byte[] encode(java.nio.ByteBuffer array)

Converts byte buffer into an array of bytes for the characters representing the hexadecimal values of each byte in order. The returned array will be double the length of the passed array, as it takes two characters to represent any given byte.

The conversion from hexadecimal characters to the returned bytes is performed with the charset named by getCharset().

All bytes identified by Buffer.remaining() will be used; after this method the value remaining() will be zero.

Parameters:

array - a byte buffer to convert to hex characters

Returns:

A byte[] containing the bytes of the lower-case hexadecimal characters

Since:

1.11

See Also:

encodeHex(byte[])

encode

public java.lang.Object encode(java.lang.Object object)
                        throws EncoderException

Converts a String or an array of bytes into an array of characters representing the hexadecimal values of each byte in order. The returned array will be double the length of the passed String or array, as it takes two characters to represent any given byte.

The conversion from hexadecimal characters to bytes to be encoded to performed with the charset named by getCharset().

Specified by:

encode in interface Encoder

Parameters:

object - a String, ByteBuffer, or byte[] to convert to hex characters

Returns:

A char[] containing lower-case hexadecimal characters

Throws:

EncoderException - Thrown if the given object is not a String or byte[]

See Also:

encodeHex(byte[])

getCharset

public java.nio.charset.Charset getCharset()

Gets the charset.

Returns:

the charset.

Since:

1.7

getCharsetName

public java.lang.String getCharsetName()

Gets the charset name.

Returns:

the charset name.

Since:

1.4

toString

public java.lang.String toString()

Returns a string representation of the object, which includes the charset name.

Overrides:

toString in class java.lang.Object

Returns:

a string representation of the object.