What you can do is use the SimpleDateFormat class to try and parse the text date into a Date object like this:
SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy");
Date mydate = sdf.parse(textdate);
if that fails than the date has the wrong format (you'll get a ParseException if I'm not mistaken).
The next step is to create a Date for 1/1/2007 and then do a date compare between your two dates. You can create a date yourself using the Calendar class.