http request is composed of three parts, namely
The request line, headers, entity
The first part is a header request and response header, the header portion and two general.
General header:
Cache-Control control caching behavior
Connection priority browser you want to use the type of link, such as keep-alive
Date created the message time
Pragma instruction message
Via proxy server information
Transfer-Encoding transfer encoding
Upgrade requires the client to upgrade agreement
Warning there may be errors in the content
Request headers:
Accept correctly received media types
Accept-Charset string correctly received
Accept-Encoding correctly received encoding format listing
Accept-Language can be correctly received the list of languages
Expect look forward to specify the behavior of the server
From requesting party-mail address
Host server domain name
Ends resource tag comparison If-Match
If-Modified-Since local resource 304 returns unmodified (comparison time)
If-None-Match returns unmodified local resource 304 (labeled Comparative)
User-Agent client information
Max-Forwards limit the number may be forwarded agents and gateways
Proxy-Authorization transmits authentication information to the proxy server
Range request part of a content
Referer represents a front page browser access
TE transfer encoding
Corresponding headers:
Accept-Ranges whether certain types of support range
Age resource exists in the proxy cache time
ETag resource identifier
Location The client is redirected to a URL
Proxy-Authenticate transmits authentication information to the proxy server
Server server name
WWW-Authenticate obtain verification of information resources needed
Entity headers:
Allow the proper way to request resources
Content-Encoding encoding format content
Content-Language Content language used
Content-Length request body length
Content-Location alternate return address data
Content Content-MD5 Base64 encrypted format MD5 check value
Content-Range position range of content
Content-Type of content media types
Expires Expires content
Last Modified Last-modified content