ASP in a Nutshell, 2nd Edition

HTTP Request and Response

Headers are the most misunderstood part of HTTP, yet understanding their role can make understanding the properties and methods of both the ASP Request and Response objects much easier.

Take a look at any Internet email message. It consists of two parts, the header and the body. The header consists of several lines that describe the body of the message and perhaps the way the message was handled as it was routed to you. The header and body are separated by a blank line. (For more information on header syntax, consult RFC-822.)

An HTTP message (either a request or a response) is structured the same way. The first line is special, but the rest of the lines up to the first blank line are headers just like in a mail message. The header describes the request and its content, if any, or the response and its content.

The request

In Section 7.1.1 we saw a number of requests from the browser. Here is another example of a simple HTTP request:

POST /cgi-win/hello.exe HTTP/1.0
Accept: image/gif, image/jpeg, */*
User-Agent: Mozilla/2.0N (Windows; I; 32Bit)
Content-type: application/x-www-form-urlencoded
Content-length: 14
[mandatory blank line]
name=Jayne+Doe

The first line, which is known as the request-line , describes the type of request (or method )—in this case POST, the URL, and, finally, the version of the HTTP protocol that the client uses. The second line describes the types of documents that the client can accept. The third line is an "extra" header that's not ...