URI貌似属于比较基本的一种协议，虽然我经常记不住它的具体格式。今天在WIKI上看到一个比较详细的格式描述，所以copy下来保留，仅此而已。
出自：http://en.wikipedia.org/wiki/URI_scheme
The following figure displays two example URIs (
出自：http://en.wikipedia.org/wiki/URI_scheme
<
scheme
name
> :
<
hierarchical
part
> [ ?
<
query
> ] [ #
<
fragment
> ]
The following figure displays two example URIs (
foo://username:password@example.com:8042/over/there/index.dtb?type=animal&name=narwhal#nose
and
urn:example:animal:ferret:nose
) and their component parts. (The examples are derived from RFC 3986 — STD 66, chapter 3).
foo://username:password@example.com:8042/over/there/index.dtb?type=animal&name=narwhal#nose
\_/ \_______________/ \_________/ \__/ \___/ \_/ \______________________/ \__/
| | | | | | | |
| userinfo host port | | query fragment
| \________________________________/\_____________|____|/ \__/ \__/
scheme | | | | | |
name authority | | | | |
| path | | interpretable as keys
| | |
| \_______________________________________________|____|/ \____/ \_____/
| | | | | |
scheme hierarchical part | | interpretable as values
name | |
| path interpretable as filename |
| ___________|____________ |
/ \ / \ |
urn:example:animal:ferret:nose interpretable as extension
path
_________|________
scheme / \
name userinfo hostname query
_|__ ___|__ ____|____ _____|_____
/ \ / \ / \ / \
mailto:username@example.com?subject=Topic
