Java™ Network Programming and Distributed Computing

10.7. ServletRequest and HttpServletRequest

The ServletRequest and HttpServletRequest classes hold all of the accessible information about the client and the server. HttpServletRequest is a subclass of ServletRequest, and is passed to each servlet handler method (such as doGet(..), doPut(..), etc.) This request may be in the form of parameters, a text or binary body, or a combination of both.

In addition, most of the standard CGI environment variables have corresponding methods that allow easy access, such as CONTENT_LENGTH and the getContentLength(). Others require an explicit request via the getHeader() method, such as HTTP_USER_AGENT and REMOTE_ADDR. Commonly used variables are shown in Table 10-2.

Table 10-2. CGI Variables that a Servlet ...