I've just released crypto-password 0.1.0, a library that implements the three most common key derivation functions, bcrypt, scrypt and PBKDF2, which are commonly used for encrypting user passwords.
The aim is to not only make it easier to use algorithms like bcrypt, but also to reduce the chance of implementation errors. There are already quite a few wrappers around the bcrypt Java classes, for example in Friend and Lib-Noir.
The library is functionally complete, but I'll keep it at 0.1.0 for a little while until it's had some time to operate in the wild.
- James