4.3. HTTP 1.1 Request Headers
Access to the request headers permits servlets to perform a number of optimizations and to provide a number of features not otherwise possible. This section presents each of the possible HTTP 1.1 request headers along with a brief summary of how servlets can make use of them. The following sections give more detailed examples.
Note that HTTP 1.1 supports a superset of the headers permitted in HTTP 1.0. For additional details on these headers, see the HTTP 1.1 specification, given in RFC 2616. There are a number of places the official RFCs are archived on-line; your best bet is to start at http://www.rfc-editor.org/ to get a current list of the archive sites.
This header specifies the MIME types that the browser ...