Elements of an HTTP URL

scheme://host[:port]/path/…/[;url-params][?query-string][#anchor]

· Scheme

o Specifies the underlying protocol

o E.g. http, ftp, mailto, …

· Host

o Identifies the computer on the internet

o Either the name or the IP address

· Port

o Optional

o Identifies the port at which the web server is listening

o It follows a colon (:)

o Web server default is 80 but may be changed when configuring the server

§ Must be specified if an alternative port number is used

· Path

o Identifies how to locate the resource on the computer

o May refer to an actual file on the computer

§ E.g. http://www.cs.etsu.edu/sites/default/files/files/2012-2013.pdf

o Includes the first forward slash

· Url-Params

o Optional

o Once rarely used but now being used more frequently for session identifiers in Java Servlet APIs

o It follows a semi-colon (;)

· Query-String

o Optional

o Contains dynamic parameters associated with the resource request

o It follows a question sign (?)

o Name value pairs are separated with the equal sign (=)

o Parameters are delimited by the ampersand sign (&)

· Anchor

o Optional

o Reference to a positional marker within the requested resource

o It follows a hash (or pound) sign (#)

http://www.somesite.com:8080/somepath/path;id=1234?name=demo&type=url#marked
Scheme:	http
Host:	www.somesite.com
Port:	8080
Path:	/somepath/path
URL Params:	id=1234
Query String:	name=demo&type=url
Anchor:	marked