Java Reference
In-Depth Information
Some of these representations may themselves be resources. For instance,
https://
www.un.org/en/documents/udhr/
identifies specifically the English version of the Uni‐
versal Declaration of Human Rights.
One of the key principles of good web architecture is to be profligate
with URIs. If anyone might want to address something or refer to
something, give it a URI (and in practice a URL). Just because a re‐
source is a part of another resource, or a collection of other resour‐
ces, or a state of another resource at a particular time, doesn't mean it
can't have its own URI. For instance, in an email service, every user,
every message received, every message sent, every filtered view of the
inbox, every contact, every filter rule, and every single page a user
might ever look at should have a unique URI.
Although architecturally URIs are opaque strings, in practice it's use‐
ful to design them with human-readable substructure. For instance,
http://mail.example.com/
might be a particular mail server,
http://
mail.example.com/johndoe
might be John Doe's mail box on that serv‐
er, and
http://mail.example.com/johndoe?messageID=162977.1361.
JavaMail.nobody%40meetup.com
might be a particular message in that
mailbox.
The syntax of a URI is composed of a scheme and a scheme-specific part, separated by
a colon, like this:
scheme
:
scheme-specific-part
The syntax of the scheme-specific part depends on the scheme being used. Current
schemes include:
data
Base64-encoded data included directly in a link; see RFC 2397
file
A file on a local disk
ftp
An FTP server
http
A World Wide Web server using the Hypertext Transfer Protocol
mailto
An email address
magnet
A resource available for download via peer-to-peer networks such as BitTorrent
