问题
I have been wondering how tiny url works.
I would like to develop something similar for my site, but as most people, I use GUIDs for ids. When an object is created, should I then generate a 10 character random string to use as public id, or is there a smarter approach?
Example of old url: www.mysite.com/default.aspx?userId={id}
Example of new url: www.mysite.com/pwzd4r9niy
回答1:
You can use any kind of random string generator or GUID for this. I don't think there is a much smarter approach. (Palantir offers a nice alternative though, hashing the incoming URL. )
The rest is relatively straightforward: Keep a database table with IDs and target URLs; When a request comes in, look up the ID and do a header redirect to the target URL.
More discussion in this blog post.
There also are redirection services out there now that use words from a dictionary list to build a URL.
Sadly, EvilURL is gone! It used to create "short" URLs like
http://evilURL.com/donkey_porn-shotguns/cracking-virus-exploit
that was the only URL redirection service really worthwhile. :)
And, as a bit of trivia, http://to is the shortest redirection service (and, I think the shortest web URL) known to man.
回答2:
Just hash the entire string, to a reasonable length.
来源：https://stackoverflow.com/questions/3193000/how-does-tiny-url-work