The case is something completely native to Java, and that's not the responsibility of JDK to support all native functionalities. Different OSes have different functionalities to drive the devices, however some devices  such as Network Adapters can be detected using JDK.

Try to find native libraries (drivers) for devices you are going to functionalize (maybe some .DLL files for MS Windows, .so files for Linux, or whatever) and using JNI (Java Native Interface) implement your own connector to the devices. (Sometimes you need to code in C/C++)

That's not so hard if you use Netbeans or Eclipse IDEs, they both have C/C++ compilers, and first try to make a HelloWorld using JNI.

You can find here enough resources for manning JNI:
http://java.sun.com/docs/books/jni/
java.sun.com/.../index.html