Minor Description
It would be nice if the properties file realm could rewrite your properties file with hashed passwords when it reads it. We would need to be able to recognize hashed vs. unhashed entries and perhaps even different algorithms. Perhaps it could go like this:
user1=plaintext
user2=MD5
user3=SHA1{...}
Anyway, the idea is that this could be a reasonably secure alternative, but you still wouldn't need to manually hash things to add or update entries – just put a plain text entry in and the next time the server reads the file it would hash it for you.
I guess we'd need to synchronize on the hash operation to avoid threading problems if multiple apps or whatever use the same properties file, but it shouldn't be bad if we only rewrite the file if we find any plain text entries.