问题
Salvete! I have discovered that a certain way of url encoding breaks the link. For the record %2f represents the forward slash character: /
Now, consider this:
Original Link: http://dottech.org/95285/this-is-the-pacific-barreleye-a-fish-with-a-transparent-head-amazing-photo-of-the-day
javascript (encodeURIComponent) urlencoded link: http://dottech.org%2f95285%2fthis-is-the-pacific-barreleye-a-fish-with-a-transparent-head-amazing-photo-of-the-day
Now, if you paste the encoded link into your browser's address bar, it is broken (Firefox, Chrome, IE).
However, if you don't url-encode the first forward slash, it works perfectly:
'http://dottech.org/95285%2fthis-is-the-pacific-barreleye-a-fish-with-a-transparent-head-amazing-photo-of-the-day
Why?
回答1:
The / is a reserved character. It’s not equivalent to %2f. If you need the slash without its defined meaning, you’d use the encoded form.
See RFC 3986: "Reserved Characters":
The purpose of reserved characters is to provide a set of delimiting characters that are distinguishable from other data within a URI. URIs that differ in the replacement of a reserved character with its corresponding percent-encoded octet are not equivalent. Percent- encoding a reserved character, or decoding a percent-encoded octet that corresponds to a reserved character, will change how the URI is interpreted by most applications.
The reason why the mentionend URL still works if you don’t use the reserved char / for the second slash: their CMS simply looks for the ID part in the URL. So you can add whatever you want to the URL, e.g. the following should still work:
http://dottech.org/95285/hey-this-URL-got-featured-at-stackoverflow
(However, it seems that it still has to be / or %2f in their case.)
If you try it with a Wikipedia article, it redirects to the front page:
http://en.wikipedia.org/wiki%2fStack_Overflow
来源：https://stackoverflow.com/questions/14631200/why-does-url-encoding-the-first-slash-after-the-domain-break-the-url