org.helidb.lang.hasher
Class StringToBigIntegerHasher

java.lang.Object
  org.helidb.lang.hasher.AbstractMessageDigestStringHasher<BigInteger>
      org.helidb.lang.hasher.StringToBigIntegerHasher

All Implemented Interfaces:

Hasher<String,BigInteger>

public class StringToBigIntegerHasher
extends AbstractMessageDigestStringHasher<BigInteger>

This Hasher uses a MessageDigest object with a configurable hash algorithm to produce a hash of a configurable length from a String. It does not support null values.

Any MessageDigest function may be used for creating the hash, as long as the hash it produces is at least as long as this object is configured to expect it to be. The hash bytes are extracted from the hash produced by the MessageDigest by taking its first bytes up to the configured length.

Since:

1.0

Author:

Karl Gustafsson

See Also:

StringToLongHasher

In_jar:

helidb-core

Field Summary

Fields inherited from class org.helidb.lang.hasher.AbstractMessageDigestStringHasher

DEFAULT_ALGORITHM

Constructor Summary

StringToBigIntegerHasher(int numLength)

StringToBigIntegerHasher(int numLength, int noOfBitsInMostSignificantByte)

StringToBigIntegerHasher(int numLength, int noOfBitsInMostSignificantByte, String hashAlgorithm, String provider, Charset cs)

Method Summary

BigInteger	fromBytes(byte[] barr) Interpret the serialized hash value.
byte[]	toBytes(BigInteger l) Serialize the hash to a byte array.

Methods inherited from class org.helidb.lang.hasher.AbstractMessageDigestStringHasher

assertNoMaskedBitsSet, createDigest, getHashLength, hash, isPreservingValues

Methods inherited from class java.lang.Object

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

Constructor Detail

StringToBigIntegerHasher

public StringToBigIntegerHasher(int numLength)
                         throws IllegalArgumentException

Throws:

IllegalArgumentException

StringToBigIntegerHasher

public StringToBigIntegerHasher(int numLength,
                                int noOfBitsInMostSignificantByte)
                         throws IllegalArgumentException

Throws:

IllegalArgumentException

StringToBigIntegerHasher

public StringToBigIntegerHasher(int numLength,
                                int noOfBitsInMostSignificantByte,
                                String hashAlgorithm,
                                String provider,
                                Charset cs)
                         throws IllegalArgumentException

Throws:

IllegalArgumentException

Method Detail

toBytes

public byte[] toBytes(BigInteger l)

Description copied from interface: Hasher

Serialize the hash to a byte array.

For a given Hasher object, the byte arrays returned by this method must always be of the same size.

Parameters:

l - The hash to serialize.

Returns:

The serialized hash.

fromBytes

public BigInteger fromBytes(byte[] barr)

Description copied from interface: Hasher

Interpret the serialized hash value.

Parameters:

barr - The serialized hash value.

Returns:

The hash value.