hey im so new to linux , any body can explain me how i can direcly control my devices like cd-rome and floppy using a c++ or java.

If your new, you need read some Guides and HOWTOs from the Linux Documentation Project:

http://www.tldp.org/

In linux, all disk drives are known as "block devices" because they work with blocks of data. In C++ and Java you will access files using either input/output streams or random access. As long as you access your drives using mounted filesystems, you can treat all "block devices" in essentially the same ways.

In order to get your filesystems mounted automatically, you may need to edit your /etc/fstab file. For more info, you can type this the terminal:

man fstab