Take a look at JNA at GitHub (latest JavaDoc). Quoting the project's description:
JNA provides Java programs easy access
to native shared libraries (DLLs on
Windows) without writing anything but
Java code—no JNI or native code is
required. This functionality is
comparable to Windows' Platform/Invoke
and Python's ctypes. Access is dynamic
at runtime without code generation.
Several projects are using it, including IntelliJ IDEA, Cassandra, and Netbeans.
