Package org.apache.pdfbox.util

Class Hex

java.lang.Object
org.apache.pdfbox.util.Hex
public final class Hex extends Object
Utility functions for hex encoding.
Author:
John Hewson

  • Method Summary

    Modifier and Type
    Method
    Description
    static byte[]
    decodeBase64(String base64Value)
    Decode a base64 String.
    static byte[]
    decodeHex(String s)
    Decodes a hex String into a byte array.
    static byte[]
    getBytes(byte b)
    Returns the bytes corresponding to the ASCII hex encoding of the given byte.
    static byte[]
    getBytes(byte[] bytes)
    Returns the bytes corresponding to the ASCII hex encoding of the given bytes.
    static char[]
    getChars(short num)
    Returns the characters corresponding to the ASCII hex encoding of the given short.
    static char[]
    getCharsUTF16BE(String text)
    Takes the characters in the given string, convert it to bytes in UTF16-BE format and build a char array that corresponds to the ASCII hex encoding of the resulting bytes.
    static int
    getHexValue(char c)
    Converts a given character to its corresponding hexadecimal value.
    static String
    getString(byte b)
    Returns a hex string of the given byte.
    static String
    getString(byte[] bytes)
    Returns a hex string of the given byte array.
    static void
    writeHexByte(byte b, OutputStream output)
    Writes the given byte as hex value to the given output stream.
    static void
    writeHexBytes(byte[] bytes, OutputStream output)
    Writes the given byte array as hex value to the given output stream.

    Methods inherited from class java.lang.Object

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

  • Method Details

    • getString

      public static String getString(byte b)
      Returns a hex string of the given byte.

    • getString

      public static String getString(byte[] bytes)
      Returns a hex string of the given byte array.

    • getBytes

      public static byte[] getBytes(byte b)
      Returns the bytes corresponding to the ASCII hex encoding of the given byte.

    • getBytes

      public static byte[] getBytes(byte[] bytes)
      Returns the bytes corresponding to the ASCII hex encoding of the given bytes.

    • getChars

      public static char[] getChars(short num)
      Returns the characters corresponding to the ASCII hex encoding of the given short.

    • getCharsUTF16BE

      public static char[] getCharsUTF16BE(String text)
      Takes the characters in the given string, convert it to bytes in UTF16-BE format and build a char array that corresponds to the ASCII hex encoding of the resulting bytes. Example: 
         getCharsUTF16BE("ab") == new char[]{'0','0','6','1','0','0','6','2'}
      Parameters:
      text - The string to convert
      Returns:
      The string converted to hex

    • writeHexByte

      public static void writeHexByte(byte b, OutputStream output) throws IOException
      Writes the given byte as hex value to the given output stream.
      Parameters:
      b - the byte to be written
      output - the output stream to be written to
      Throws:
      IOException - exception if anything went wrong

    • writeHexBytes

      public static void writeHexBytes(byte[] bytes, OutputStream output) throws IOException
      Writes the given byte array as hex value to the given output stream.
      Parameters:
      bytes - the byte array to be written
      output - the output stream to be written to
      Throws:
      IOException - exception if anything went wrong

    • decodeBase64

      public static byte[] decodeBase64(String base64Value)
      Decode a base64 String.
      Parameters:
      base64Value - a base64 encoded String.
      Returns:
      the decoded String as a byte array.
      Throws:
      IllegalArgumentException - if this isn't a base64 encoded string.

    • decodeHex

      public static byte[] decodeHex(String s) throws IOException
      Decodes a hex String into a byte array.
      Parameters:
      s - A String with ASCII hex.
      Returns:
      decoded byte array.
      Throws:
      IOException

    • getHexValue

      public static int getHexValue(char c)
      Converts a given character to its corresponding hexadecimal value. Valid characters are '0'-'9', 'A'-'F', or 'a'-'f'. Returns -256 for invalid characters.

      The value of -256 is chosen so that to hex digits can be combined before checking for an invalid hex string

      Parameters:
      c - the character to be converted to a hexadecimal value
      Returns:
      the hexadecimal value of the character, or -256 if the character is invalid