Package com.amazonaws.encryptionsdk.internal

Class Utils

java.lang.Object

com.amazonaws.encryptionsdk.internal.Utils

public final class Utils
extends Object

Internal utility methods.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Utils.ComparingByteArrays	Comparator that performs a lexicographical comparison of byte arrays, treating them as unsigned.
static class	Utils.ComparingByteBuffers

Method Summary

Modifier and Type	Method	Description
static <T> T	assertNonNull(T object, String paramName)	Throws NullPointerException with message paramName if object is null.
static int	compareObjectIdentity(Object a, Object b)	Provides an arbitrary but consistent total ordering over all objects.
static SecureRandom	getSecureRandom()
static long	saturatingAdd(long a, long b)
static byte[]	truncate(byte[] arr, int len)	Returns a possibly truncated version of arr which is guaranteed to be exactly len elements long.

Methods inherited from class java.lang.Object

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

Method Detail

compareObjectIdentity

public static int compareObjectIdentity(Object a,
                                        Object b)

Provides an arbitrary but consistent total ordering over all objects. This comparison function will return 0 if and only if a == b, and otherwise will return arbitrarily either -1 or 1, but will do so in a way that results in a consistent total order.

Parameters:

a -

b -

Returns:

-1 or 1 (consistently) if a != b; 0 if a == b.

saturatingAdd

public static long saturatingAdd(long a,
                                 long b)

assertNonNull

public static <T> T assertNonNull(T object,
                                  String paramName)
                           throws NullPointerException

Throws NullPointerException with message paramName if object is null.

Parameters:

object - value to be null-checked

paramName - message for the potential NullPointerException

Returns:

object

Throws:

NullPointerException - if object is null

truncate

public static byte[] truncate(byte[] arr,
                              int len)
                       throws IllegalArgumentException

Returns a possibly truncated version of arr which is guaranteed to be exactly len elements long. If arr is already exactly len elements long, then arr is returned without copy or modification. If arr is longer than len, then a truncated copy is returned. If arr is shorter than len then this throws an IllegalArgumentException.

Throws:

IllegalArgumentException

getSecureRandom

public static SecureRandom getSecureRandom()