<input type="date" name="dob" required>

this is the html5 date picker

String date=request.getParameter("dob").toString()

how to get value from tat date picker

The date is just a String value, so you could simply parse it using a SimpleDateFormatter.

I'm assuming your variable name of date here:

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
Date parsed = format.parse(date);

That of course assumes that your date is in this format. That might be different, if so, you'll have to play with the date format. Depending on your framework, like, for example, Spring, there might be utility methods available to help out with this as well.