Search:

Start by reading the API doc for the File class and finding the method to use.
Then use that method in a program.
The API doc: Java Platform SE 7

You can get that with a method of the File class.

What is a file version?
Is it something created by the OS like Date last modified?
Is it in the contents of the file?
Is it in the filename?

You'll need to know that before you can get a...

Do you have any specific questions about your problemt?
Please post your code and any questions about problems you are having.