More Servlets and JavaServer Pages™

2.8. The Server Response: HTTP Response Headers

As discussed in the previous section, a response from a Web server normally consists of a status line, one or more response headers (one of which must be Content-Type), a blank line, and the document. To get the most out of your servlets, you need to know how to use the status line and response headers effectively, not just how to generate the document.

Setting the HTTP response headers often goes hand in hand with setting the status codes in the status line, as discussed in the previous section. For example, all the “document moved” status codes (300 through 307) have an accompanying Location header, and a 401 (Unauthorized) code always includes an accompanying WWW-Authenticate header. However, ...