Hello all,
This concerns the current SVN trunk.
The javadoc in IDMigrator:
/**
* @return the top 8 bytes of the MD5 hash of the bytes of the given
{...@link String}'s UTF-8 encoding as a long.
* The reverse mapping is also stored.
* @throws TasteException if an error occurs while storing the mapping
*/
long toLongID(String stringID);
However in AbstractIDMigrator, the method is implemented without a call to
storeMapping().
@Override
public long toLongID(String stringID) {
return hash(stringID);
}
/**
* @return most significant 8 bytes of the MD5 hash of the string, as a
long
*/
protected final long hash(String value) {
byte[] md5hash;
synchronized (md5Digest) {
md5hash = md5Digest.digest(value.getBytes(UTF8_CHARSET));
md5Digest.reset();
}
long hash = 0L;
for (int i = 0; i < 8; i++) {
hash = (hash << 8) | (md5hash[i] & 0x00000000000000FFL);
}
return hash;
}
So, it is possible to migrate a String ID to a long but not possible to do a
reverse lookup. This affects MemoryIDMigrator and would affect other
classes that extend AbstractIDMigrator but do not override toLongID().
For example:
IDMigrator idMigratorTest = new MemoryIDMigrator();
long migratedId = idMigratorTest.toLongID("someStringId");
String stringId = idMigratorTest.toStringID(migratedId);
System.out.println("migratedId=" + migratedId + "; stringId="
+ stringId);
Will output:
migratedId=___some_long_value___; stringId=null
Is this a bug or am I just not correctly using the class?
- Y
