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
<scheme name> : <hierarchical part> [ ? <query> ] [ # <fragment> ]
the following figure displays two example uris (<code>foo://username:[email protected]:8042/over/there/index.dtb?type=animal&name=narwhal#nose</code> and<code>urn:example:animal:ferret:nose</code>) and their component parts. (the examples are derived from rfc 3986 — std 66, chapter 3).