Simple library for arithmetic expression pasring and evaluating

[John Doe]

Hello,

i'm searching for a simple java library wich has methods for parsing and
evaluating (with float or double) simple arithmetic expression. Let's
say it can use the 4 operators ans some cos/sin/tan/... functions.

I'm not searching for a CAS (Computer Algebra Systems) but just a
parser, which give an AST (Asbract Syntax Tree), and an evaluator to
calulate the result of the expression as a float or double.

The library must be free (0$), open source not needed.

Please post if you know such a library.

Thx