Head First Servlets and JSP, 2nd Edition

Besides parameters, what else can I get from a Request object?

The ServletRequest and HttpServletRequest interfaces have a ton of methods you can call, but you don’t need to memorize them all. On your own, you really should look at the full API for javax.servlet. ServletRequest and javax.servlet.http.HttpServletRequest, but here we’ll look at only the methods you’re most likely to use in your work (and which might also show up on the exam).

In the real world, you’ll be lucky (or unlucky, depending on your perspective), to use more than 15% of the request API. Don’t worry if you aren’t clear about how or why you’d use each of these; we’ll see more details on some of them (especially cookies) later in the book.

The client’s platform and browser info

String client = request.getHeader("User-Agent");

The cookies associated with this request

Cookie[] cookies = request.getCookies();

The session associated with this client

HttpSession session = request.getSession();

The HTTP Method of the request

String theMethod = request.getMethod();

An input stream from the request

ServletInputStream input = getInputStream();

There are no Dumb Questions

Q:	Q: Why would I ever want to get an InputStream from the request?
A:	A: With a GET request, there’s nothing but the request header info. In other words, there’s no body to care about. BUT... with an HTTP POST, there’s body info. Most of the time, all you care about from ...