org.yamcs.utils

Class ByteArrayUtils

java.lang.Object

org.yamcs.utils.ByteArrayUtils

public class ByteArrayUtils
extends Object

Constructor Summary

Constructors

Constructor and Description
ByteArrayUtils()

Method Summary

Modifier and Type	Method and Description
static int	compare(byte[] a1, byte[] a2) lexicographic comparison which returns 0 if one of the array is a subarray of the other one
static int	decodeInt(byte[] a, int offset)
static int	decodeShort(byte[] a, int offset)
static byte[]	encodeInt(int x, byte[] a, int offset) write an int into a byte array at offset and returns the array
static byte[]	encodeLong(long x, byte[] a, int offset) write an long into a byte array at offset and returns the array
static boolean	equalsPrefix(byte[] a, byte[] b, int n) Compares the first n bytes of two arrays.
static byte[]	plusOne(byte[] a) If the array is considered binary representation of an integer, add 1 to the integer and returns the corresponding binary representation.
static boolean	startsWith(byte[] a, byte[] b) returns true if a starts with b

Methods inherited from class java.lang.Object

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

Constructor Detail

ByteArrayUtils

public ByteArrayUtils()

Method Detail

startsWith

public static boolean startsWith(byte[] a,
                                 byte[] b)

returns true if a starts with b

Parameters:

a -

b -

Returns:

true if a and b are not null, a.length ≥ b.length and a[i]=b[i] for i=0...b.length-1

Throws:

NullPointerException - if any of them is null

equalsPrefix

public static boolean equalsPrefix(byte[] a,
                                   byte[] b,
                                   int n)

Compares the first n bytes of two arrays. The arrays must be at least n bytes long (otherwise false is returned)

Parameters:

a - - the first array to compare

b - - the second array to compare

n - - the number of bytes to compare

Returns:

true if a.length >= n, b.length >= n and a[i]==b[i] for i=0..n-1

Throws:

NullPointerException - if any of them is null

plusOne

public static byte[] plusOne(byte[] a)

If the array is considered binary representation of an integer, add 1 to the integer and returns the corresponding binary representation. In case an overflow is detected (if the initial array was all 0XFF) an IllegalArgumentException is thrown.

Parameters:

a -

Returns:

a+1

compare

public static int compare(byte[] a1,
                          byte[] a2)

lexicographic comparison which returns 0 if one of the array is a subarray of the other one

Parameters:

a1 -

a2 -

encodeInt

public static byte[] encodeInt(int x,
                               byte[] a,
                               int offset)

write an int into a byte array at offset and returns the array

encodeLong

public static byte[] encodeLong(long x,
                                byte[] a,
                                int offset)

write an long into a byte array at offset and returns the array

decodeInt

public static int decodeInt(byte[] a,
                            int offset)

decodeShort

public static int decodeShort(byte[] a,
                              int offset)