at.favre.lib.bytes

Class BytesTransformers

java.lang.Object

at.favre.lib.bytes.BytesTransformers

public final class BytesTransformers
extends Object

Collection of additional BytesTransformer for more specific use cases

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BytesTransformers.ChecksumTransformer Adds or converts to arbitrary checksum
static class	BytesTransformers.GzipCompressor Byte compression with gzip
static class	BytesTransformers.HmacTransformer HMAC transformer
static class	BytesTransformers.ShuffleTransformer Shuffles the internal byte array
static class	BytesTransformers.SortTransformer Sorts the internal byte array with given Comparator

Method Summary

Modifier and Type	Method and Description
static BytesTransformer	checksum(Checksum checksum, BytesTransformers.ChecksumTransformer.Mode mode, int checksumLengthByte) Create a BytesTransformer which transforms to 4 byte Crc32 checksum of given bytes
static BytesTransformer	checksumAppendCrc32() Create a BytesTransformer which appends 4 byte Crc32 checksum to given bytes
static BytesTransformer	checksumCrc32() Create a BytesTransformer which transforms to 4 byte Crc32 checksum of given bytes
static BytesTransformer	compressGzip() Create a BytesTransformer which gzip compresses the internal byte array
static BytesTransformer	decompressGzip() Create a BytesTransformer which gzip decompresses the internal byte array
static BytesTransformer	hmac(byte[] key, String algorithmName) Create a BytesTransformer which returns the HMAC with given key, algorithm of the target byte array
static BytesTransformer	hmacSha1(byte[] key) Create a BytesTransformer which returns the HMAC-SHA1 with given key, of the target byte array
static BytesTransformer	hmacSha256(byte[] key) Create a BytesTransformer which returns the HMAC-SHA256 with given key, of the target byte array
static BytesTransformer	shuffle() Create a BytesTransformer which shuffles the individual bytes in an array with an SecureRandom instance.
static BytesTransformer	shuffle(Random random) Create a BytesTransformer which shuffles the individual bytes in an array
static BytesTransformer	sort() Create a BytesTransformer which sorts the internal byte array with it's natural ordering treating each byte as signed byte (-128...127).
static BytesTransformer	sort(Comparator<Byte> comparator) Create a BytesTransformer which sorts the internal byte array according to given comparator.
static BytesTransformer	sortUnsigned() Create a BytesTransformer which sorts the internal byte array with it's natural ordering treating each byte as unsigned byte (0...255).

Methods inherited from class java.lang.Object

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

Method Detail

shuffle

public static BytesTransformer shuffle()

Create a BytesTransformer which shuffles the individual bytes in an array with an SecureRandom instance.

Returns:

transformer

shuffle

public static BytesTransformer shuffle(Random random)

Create a BytesTransformer which shuffles the individual bytes in an array

Parameters:

random - to use for entropy

Returns:

transformer

sort

public static BytesTransformer sort()

Create a BytesTransformer which sorts the internal byte array with it's natural ordering treating each byte as signed byte (-128...127). Using inplace sorting, this can be reasonable fast.

Returns:

transformer

sortUnsigned

public static BytesTransformer sortUnsigned()

Create a BytesTransformer which sorts the internal byte array with it's natural ordering treating each byte as unsigned byte (0...255). That is, the byte string ff sorts after 00. Note: this requires 2 copies of the internal array and a lot of unboxing due to the fact that no primitives are not allowed as generic type arguments - so only use on small arrays.

Returns:

transformer

sort

public static BytesTransformer sort(Comparator<Byte> comparator)

Create a BytesTransformer which sorts the internal byte array according to given comparator. Note: this requires 2 copies of the internal array and a lot of unboxing due to the fact that no primitives are not allowed as generic type arguments - so only use on small arrays.

Parameters:

comparator - to sort the bytes

Returns:

transformer

checksumAppendCrc32

public static BytesTransformer checksumAppendCrc32()

Create a BytesTransformer which appends 4 byte Crc32 checksum to given bytes

Returns:

transformer

checksumCrc32

public static BytesTransformer checksumCrc32()

Create a BytesTransformer which transforms to 4 byte Crc32 checksum of given bytes

Returns:

transformer

checksum

public static BytesTransformer checksum(Checksum checksum,
                                        BytesTransformers.ChecksumTransformer.Mode mode,
                                        int checksumLengthByte)

Create a BytesTransformer which transforms to 4 byte Crc32 checksum of given bytes

Parameters:

checksum - used algorithm

mode - mode (append or convert)

checksumLengthByte - the byte length of the checksum; the Checksum class always returns 8 byte, but some checksum algorithms (e.g. CRC32) only require smaller output. Must be between 1 and 8 byte.

Returns:

transformer

compressGzip

public static BytesTransformer compressGzip()

Create a BytesTransformer which gzip compresses the internal byte array

Returns:

transformer

Throws:

IllegalStateException - if compression was not possible (i.e. wrapped IOException)

See Also:

Gzip

decompressGzip

public static BytesTransformer decompressGzip()

Create a BytesTransformer which gzip decompresses the internal byte array

Returns:

transformer

Throws:

IllegalStateException - if compression was not possible (i.e. wrapped IOException)

See Also:

Gzip

hmacSha1

public static BytesTransformer hmacSha1(byte[] key)

Create a BytesTransformer which returns the HMAC-SHA1 with given key, of the target byte array

Parameters:

key - to use for HMAC

Returns:

hmac

hmacSha256

public static BytesTransformer hmacSha256(byte[] key)

Create a BytesTransformer which returns the HMAC-SHA256 with given key, of the target byte array

Parameters:

key - to use for HMAC

Returns:

hmac

hmac

public static BytesTransformer hmac(byte[] key,
                                    String algorithmName)

Create a BytesTransformer which returns the HMAC with given key, algorithm of the target byte array

Parameters:

key - to use for HMAC

algorithmName - e.g. 'HmacSHA256' - check if the algorithm is supported on your JVM/runtime

Returns:

hmac (length depends on algorithm)