Package com.globalmentor.java

Class Bytes

java.lang.Object
com.globalmentor.java.Bytes
public final class Bytes extends Object
Utilities for manipulating bytes.
Author:
Garret Wilson

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final byte[]
    NO_BYTES
    A shared empty array of bytes.

  • Method Summary

    Modifier and Type
    Method
    Description
    static byte[]
    fromHexString(CharSequence hex)
    Converts a sequence of hex values to bytes, without regard to case.
    static byte[]
    generateRandom(int length)
    Creates an array of random bytes.
    static byte[]
    generateRandom(int length, Random random)
    Creates an array of random bytes.
    static boolean
    startsWith(byte[] bytes, byte[] prefix)
    Determines if the given byte array starts with the specified prefix.
    static String
    toHexString(byte[] bytes)
    Converts an array of bytes into a lowercase hex string, with each character pair representing the hexadecimal value of the byte.

    Methods inherited from class java.lang.Object

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

  • Field Details

    • NO_BYTES

      public static final byte[] NO_BYTES
      A shared empty array of bytes.

  • Method Details

    • toHexString

      public static String toHexString(byte[] bytes)
      Converts an array of bytes into a lowercase hex string, with each character pair representing the hexadecimal value of the byte.
      Parameters:
      bytes - The values to convert.
      Returns:
      A lowercase string with hexadecimal digits, each pair representing a byte in the byte array.
      See Also:

    • fromHexString

      public static byte[] fromHexString(@Nonnull CharSequence hex)
      Converts a sequence of hex values to bytes, without regard to case.
      Implementation Note:
      This implementation modified from an answer on Stack Overflow.
      Parameters:
      hex - The two-digit hex values to convert.
      Returns:
      The equivalent bytes of the hex characters.
      Throws:
      IllegalArgumentException - if a hex value is missing one of its pairs (i.e. the sequence length is odd) or if a hex representation contains an invalid character.
      See Also:

    • generateRandom

      public static byte[] generateRandom(@Nonnegative int length)
      Creates an array of random bytes.
      Implementation Specification:
      This implementation delegates to generateRandom(int, Random) using a default Random instance.
      Parameters:
      length - The number of bytes to create.
      Returns:
      A new array of the given length filled with random bytes.
      Throws:
      IllegalArgumentException - if the given length is negative.
      See Also:

    • generateRandom

      public static byte[] generateRandom(@Nonnegative int length, @Nonnull Random random)
      Creates an array of random bytes.
      Parameters:
      length - The number of bytes to create.
      random - The random number generator to use.
      Returns:
      A new array of the given length filled with random bytes.
      Throws:
      NullPointerException - if the given random number generator is null.
      IllegalArgumentException - if the given length is negative.
      See Also:

    • startsWith

      public static boolean startsWith(byte[] bytes, byte[] prefix)
      Determines if the given byte array starts with the specified prefix. Neither byte array is modified by this method.
      Parameters:
      bytes - The bytes being examined.
      prefix - The prefix to compare with the given bytes.
      Returns:
      Whether the given bytes start with the specified prefix.