cd.. in java

[mm2236]

Hi
i want to save the user some typing, allow the user to type “..” to mean that the change directory should go up one level to the parent directory.
for example c:\1\2\3
if i write ..
output : c:\1\2

but my output is c:\

private void detailFile(DataInputStream in, ObjectOutputStream oOut) {
        try {
            String fileName = in.readUTF();

            File tmp = new File(file, fileName);

            if (tmp.isFile()) {
                oOut.writeObject(tmp);
            } else {
                oOut.writeObject(null);
            }

            fileName = null;
            tmp = null;
        } catch (Exception e) {
            try {
                oOut.writeObject(null);
            } catch (Exception e2) {
            }
        }
    }

plz help me
thanks

[Eranga]

What's the combination of the code you post and the question?