com.google.common.primitives
Class UnsignedBytes

java.lang.Object
  com.google.common.primitives.UnsignedBytes

public final class UnsignedBytes
extends Object

Static utility methods pertaining to byte primitives that interpret values as unsigned (that is, any negative value b is treated as the positive value 256 + b). The corresponding methods that treat the values as signed are found in SignedBytes, and the methods for which signedness is not an issue are in Bytes.

Since:

1.0

Author:

Kevin Bourrillion, Martin Buchholz, Hiroshi Yamauchi

Field Summary

static byte

MAX_POWER_OF_TWO The largest power of two that can be represented as an unsigned byte.

Method Summary

static byte	checkedCast(long value) Returns the byte value that, when treated as unsigned, is equal to value, if possible.
static int	compare(byte a, byte b) Compares the two specified byte values, treating them as unsigned values between 0 and 255 inclusive.
static String	join(String separator, byte... array) Returns a string containing the supplied byte values separated by separator.
static Comparator<byte[]>	lexicographicalComparator() Returns a comparator that compares two byte arrays lexicographically.
static byte	max(byte... array) Returns the greatest value present in array.
static byte	min(byte... array) Returns the least value present in array.
static byte	saturatedCast(long value) Returns the byte value that, when treated as unsigned, is nearest in value to value.
static int	toInt(byte value) Returns the value of the given byte as an integer, when treated as unsigned.

Methods inherited from class java.lang.Object

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

Field Detail

MAX_POWER_OF_TWO

public static final byte MAX_POWER_OF_TWO

The largest power of two that can be represented as an unsigned byte.

Since:

10.0

See Also:

Constant Field Values

Method Detail

toInt

public static int toInt(byte value)

Returns the value of the given byte as an integer, when treated as unsigned. That is, returns value + 256 if value is negative; value itself otherwise.

Since:

6.0

checkedCast

public static byte checkedCast(long value)

Returns the byte value that, when treated as unsigned, is equal to value, if possible.

Parameters:

value - a value between 0 and 255 inclusive

Returns:

the byte value that, when treated as unsigned, equals value

Throws:

IllegalArgumentException - if value is negative or greater than 255

saturatedCast

public static byte saturatedCast(long value)

Returns the byte value that, when treated as unsigned, is nearest in value to value.

Parameters:

value - any long value

Returns:

(byte) 255 if value >= 255, (byte) 0 if value <= 0, and value cast to byte otherwise

compare

public static int compare(byte a,
                          byte b)

Compares the two specified byte values, treating them as unsigned values between 0 and 255 inclusive. For example, (byte) -127 is considered greater than (byte) 127 because it is seen as having the value of positive 129.

Parameters:

a - the first byte to compare

b - the second byte to compare

Returns:

a negative value if a is less than b; a positive value if a is greater than b; or zero if they are equal

min

public static byte min(byte... array)

Returns the least value present in array.

Parameters:

array - a nonempty array of byte values

Returns:

the value present in array that is less than or equal to every other value in the array

Throws:

IllegalArgumentException - if array is empty

max

public static byte max(byte... array)

Returns the greatest value present in array.

Parameters:

array - a nonempty array of byte values

Returns:

the value present in array that is greater than or equal to every other value in the array

Throws:

IllegalArgumentException - if array is empty

join

public static String join(String separator,
                          byte... array)

Returns a string containing the supplied byte values separated by separator. For example, join(":", (byte) 1, (byte) 2, (byte) 255) returns the string "1:2:255".

Parameters:

separator - the text that should appear between consecutive values in the resulting string (but not at the start or end)

array - an array of byte values, possibly empty

lexicographicalComparator

public static Comparator<byte[]> lexicographicalComparator()

Returns a comparator that compares two byte arrays lexicographically. That is, it compares, using compare(byte, byte)), the first pair of values that follow any common prefix, or when one array is a prefix of the other, treats the shorter array as the lesser. For example, [] < [0x01] < [0x01, 0x7F] < [0x01, 0x80] < [0x02]. Values are treated as unsigned.

The returned comparator is inconsistent with Object.equals(Object) (since arrays support only identity equality), but it is consistent with Arrays.equals(byte[], byte[]).

Since:

2.0

See Also:

Lexicographical order article at Wikipedia