It's a strange thing to need to know. Are you just curious, or is
there a real problem you can't solve without knowing this information?

Anyway pure Java does provide any mechanisms to do that. This is
probably one of the more portable solutions but requires an external
helper that's available on Unix and Unix-like systems:

 Runtime.getRuntime().exec("lsof " + filename);

On Windows there is Process Explorer:

 http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx

But whether you can use it from your java application is another
story.

You might look into solutions based on JNI.

/gordon

--