Class Bytes

java.lang.Object
com.google.common.primitives.Bytes
@GwtCompatible public final class Bytes extends Object
Static utility methods pertaining to byte primitives, that are not already found in either Byte or Arrays, and interpret bytes as neither signed nor unsigned. The methods which specifically treat bytes as signed or unsigned are found in SignedBytes and UnsignedBytes.

See the Guava User Guide article on primitive utilities.

Since:
1.0
Author:
Kevin Bourrillion

  • Method Summary

    Modifier and Type
    Method
    Description
    static List<Byte>
    asList(byte... backingArray)
    Returns a fixed-size list backed by the specified array, similar to Arrays.asList(Object[]).
    static byte[]
    concat(byte[]... arrays)
    Returns the values from each provided array combined into a single array.
    static boolean
    contains(byte[] array, byte target)
    Returns true if target is present as an element anywhere in array.
    static byte[]
    ensureCapacity(byte[] array, int minLength, int padding)
    Returns an array containing the same values as array, but guaranteed to be of a specified minimum length.
    static int
    hashCode(byte value)
    Returns a hash code for value; equal to the result of invoking ((Byte) value).hashCode().
    static int
    indexOf(byte[] array, byte target)
    Returns the index of the first appearance of the value target in array.
    static int
    indexOf(byte[] array, byte[] target)
    Returns the start position of the first occurrence of the specified target within array, or -1 if there is no such occurrence.
    static int
    lastIndexOf(byte[] array, byte target)
    Returns the index of the last appearance of the value target in array.
    static void
    reverse(byte[] array)
    Reverses the elements of array.
    static void
    reverse(byte[] array, int fromIndex, int toIndex)
    Reverses the elements of array between fromIndex inclusive and toIndex exclusive.
    static void
    rotate(byte[] array, int distance)
    Performs a right rotation of array of "distance" places, so that the first element is moved to index "distance", and the element at index i ends up at index (distance + i) mod array.length.
    static void
    rotate(byte[] array, int distance, int fromIndex, int toIndex)
    Performs a right rotation of array between fromIndex inclusive and toIndex exclusive.
    static byte[]
    toArray(Collection<? extends Number> collection)
    Returns an array containing each value of collection, converted to a byte value in the manner of Number.byteValue().

    Methods inherited from class java.lang.Object

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

  • Method Details

    • hashCode

      public static int hashCode(byte value)
      Returns a hash code for value; equal to the result of invoking ((Byte) value).hashCode().

      Java 8+ users: use Byte.hashCode(byte) instead.

      Parameters:
      value - a primitive byte value
      Returns:
      a hash code for the value

    • contains

      public static boolean contains(byte[] array, byte target)
      Returns true if target is present as an element anywhere in array.
      Parameters:
      array - an array of byte values, possibly empty
      target - a primitive byte value
      Returns:
      true if array[i] == target for some value of i

    • indexOf

      public static int indexOf(byte[] array, byte target)
      Returns the index of the first appearance of the value target in array.
      Parameters:
      array - an array of byte values, possibly empty
      target - a primitive byte value
      Returns:
      the least index i for which array[i] == target, or -1 if no such index exists.

    • indexOf

      public static int indexOf(byte[] array, byte[] target)
      Returns the start position of the first occurrence of the specified target within array, or -1 if there is no such occurrence.

      More formally, returns the lowest index i such that Arrays.copyOfRange(array, i, i + target.length) contains exactly the same elements as target.

      Parameters:
      array - the array to search for the sequence target
      target - the array to search for as a sub-sequence of array

    • lastIndexOf

      public static int lastIndexOf(byte[] array, byte target)
      Returns the index of the last appearance of the value target in array.
      Parameters:
      array - an array of byte values, possibly empty
      target - a primitive byte value
      Returns:
      the greatest index i for which array[i] == target, or -1 if no such index exists.

    • concat

      public static byte[] concat(byte[]... arrays)
      Returns the values from each provided array combined into a single array. For example, concat(new byte[] {a, b}, new byte[] {}, new byte[] {c} returns the array {a, b, c}.
      Parameters:
      arrays - zero or more byte arrays
      Returns:
      a single array containing all the values from the source arrays, in order
      Throws:
      IllegalArgumentException - if the total number of elements in arrays does not fit in an int

    • ensureCapacity

      public static byte[] ensureCapacity(byte[] array, int minLength, int padding)
      Returns an array containing the same values as array, but guaranteed to be of a specified minimum length. If array already has a length of at least minLength, it is returned directly. Otherwise, a new array of size minLength + padding is returned, containing the values of array, and zeroes in the remaining places.
      Parameters:
      array - the source array
      minLength - the minimum length the returned array must guarantee
      padding - an extra amount to "grow" the array by if growth is necessary
      Returns:
      an array containing the values of array, with guaranteed minimum length minLength
      Throws:
      IllegalArgumentException - if minLength or padding is negative

    • toArray

      public static byte[] toArray(Collection<? extends Number> collection)
      Returns an array containing each value of collection, converted to a byte value in the manner of Number.byteValue().

      Elements are copied from the argument collection as if by collection.toArray(). Calling this method is as thread-safe as calling that method.

      Parameters:
      collection - a collection of Number instances
      Returns:
      an array containing the same values as collection, in the same order, converted to primitives
      Throws:
      NullPointerException - if collection or any of its elements is null
      Since:
      1.0 (parameter was Collection<Byte> before 12.0)

    • asList

      public static List<Byte> asList(byte... backingArray)
      Returns a fixed-size list backed by the specified array, similar to Arrays.asList(Object[]). The list supports List.set(int, Object), but any attempt to set a value to null will result in a NullPointerException.

      The returned list maintains the values, but not the identities, of Byte objects written to or read from it. For example, whether list.get(0) == list.get(0) is true for the returned list is unspecified.

      The returned list is serializable.

      Parameters:
      backingArray - the array to back the list
      Returns:
      a list view of the array

    • reverse

      public static void reverse(byte[] array)
      Reverses the elements of array. This is equivalent to Collections.reverse(Bytes.asList(array)), but is likely to be more efficient.
      Since:
      23.1

    • reverse

      public static void reverse(byte[] array, int fromIndex, int toIndex)
      Reverses the elements of array between fromIndex inclusive and toIndex exclusive. This is equivalent to Collections.reverse(Bytes.asList(array).subList(fromIndex, toIndex)), but is likely to be more efficient.
      Throws:
      IndexOutOfBoundsException - if fromIndex < 0, toIndex > array.length, or toIndex > fromIndex
      Since:
      23.1

    • rotate

      public static void rotate(byte[] array, int distance)
      Performs a right rotation of array of "distance" places, so that the first element is moved to index "distance", and the element at index i ends up at index (distance + i) mod array.length. This is equivalent to Collections.rotate(Bytes.asList(array), distance), but is somewhat faster.

      The provided "distance" may be negative, which will rotate left.

      Since:
      32.0.0

    • rotate

      public static void rotate(byte[] array, int distance, int fromIndex, int toIndex)
      Performs a right rotation of array between fromIndex inclusive and toIndex exclusive. This is equivalent to Collections.rotate(Bytes.asList(array).subList(fromIndex, toIndex), distance), but is somewhat faster.

      The provided "distance" may be negative, which will rotate left.

      Throws:
      IndexOutOfBoundsException - if fromIndex < 0, toIndex > array.length, or toIndex > fromIndex
      Since:
      32.0.0