How to manage Folders[faster reply required]

Hi,I'm trying to display the list of files & folders under the specified path.I'm using an array to store the directory names.When I check for the files in those folders I delete that entry from the array.But I find it inefficient,moreover I want to display the size of the folder which can be got only by calculating the total size of the files in the sub-folders.So please help me out to finish this.Reply me as soon as possible.
Happy middling with java.

Netharam.:confused