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 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 final Charset
    DEFAULT_CHARSET
    Default charset is StandardCharsets.UTF_8.
    static final 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(String charsetName)
    Creates a new codec with the given charset name.
    Hex(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.
    Object
    decode(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(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(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.
    Object
    encode(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(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(ByteBuffer data)
    Converts a byte buffer into an array of characters representing the hexadecimal values of each byte in order.
    static char[]
    encodeHex(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(ByteBuffer byteBuffer, char[] toDigits)
    Converts a byte buffer into an array of characters representing the hexadecimal values of each byte in order.
    static String
    encodeHexString(byte[] data)
    Converts an array of bytes into a String representing the hexadecimal values of each byte in order.
    static String
    encodeHexString(byte[] data, boolean toLowerCase)
    Converts an array of bytes into a String representing the hexadecimal values of each byte in order.
    static String
    encodeHexString(ByteBuffer data)
    Converts a byte buffer into a String representing the hexadecimal values of each byte in order.
    static String
    encodeHexString(ByteBuffer data, boolean toLowerCase)
    Converts a byte buffer into a String representing the hexadecimal values of each byte in order.
    Charset
    getCharset()
    Gets the charset.
    String
    getCharsetName()
    Gets the charset name.
    protected static int
    toDigit(char ch, int index)
    Converts a hexadecimal character to an integer.
    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 Details

  • Constructor Details

    • Hex

      public Hex()
      Creates a new codec with the default charset name DEFAULT_CHARSET

    • Hex

      public Hex(Charset charset)
      Creates a new codec with the given Charset.
      Parameters:
      charset - the charset.
      Since:
      1.7

    • Hex

      public Hex(String charsetName)
      Creates a new codec with the given charset name.
      Parameters:
      charsetName - the charset name.
      Throws:
      UnsupportedCharsetException - If the named charset is unavailable
      Since:
      1.4, 1.7 throws UnsupportedCharsetException if the named charset is unavailable

  • Method Details

    • 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(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 hexadecimal 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 hexadecimal 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 hexadecimal 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 hexadecimal 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(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 hexadecimal characters
      Returns:
      A char[] containing lower-case hexadecimal characters
      Since:
      1.11

    • encodeHex

      public static char[] encodeHex(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 hexadecimal 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(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 hexadecimal 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 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 hexadecimal characters
      Returns:
      A String containing lower-case hexadecimal characters
      Since:
      1.4

    • encodeHexString

      public static 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 hexadecimal characters
      toLowerCase - true converts to lowercase, false to uppercase
      Returns:
      A String containing lower-case hexadecimal characters
      Since:
      1.11

    • encodeHexString

      public static String encodeHexString(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 hexadecimal characters
      Returns:
      A String containing lower-case hexadecimal characters
      Since:
      1.11

    • encodeHexString

      public static String encodeHexString(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 hexadecimal 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 hexadecimal 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:

    • decode

      public byte[] decode(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:

    • decode

      public Object decode(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:

    • 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 hexadecimal 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:

    • encode

      public byte[] encode(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 hexadecimal characters
      Returns:
      A byte[] containing the bytes of the lower-case hexadecimal characters
      Since:
      1.11
      See Also:

    • encode

      public Object encode(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 hexadecimal characters
      Returns:
      A char[] containing lower-case hexadecimal characters
      Throws:
      EncoderException - Thrown if the given object is not a String or byte[]
      See Also:

    • getCharset

      public Charset getCharset()
      Gets the charset.
      Returns:
      the charset.
      Since:
      1.7

    • getCharsetName

      public String getCharsetName()
      Gets the charset name.
      Returns:
      the charset name.
      Since:
      1.4

    • toString

      public String toString()
      Returns a string representation of the object, which includes the charset name.
      Overrides:
      toString in class Object
      Returns:
      a string representation of the object.