How to determine if a given URL link is a video or image?

Question

I\'m trying to take a given URL entered by user and determine if the URL is pointing to a image or a video.

Example use case:

When a user paste in the URL o

Answer 1

Issue an HTTP HEAD request so you can examine the HTTP headers that come back without having to first download the entire document. Showing a non-programmatic case under Linux using "curl":

$ curl --head http://stackoverflow.com/Content/Img/stackoverflow-logo-250.png
HTTP/1.1 200 OK
Cache-Control: max-age=28800
Content-Length: 3428
Content-Type: image/png
Last-Modified: Fri, 16 Jan 2009 09:35:30 GMT
Accept-Ranges: bytes
ETag: "98f590c5bd77c91:0"
Server: Microsoft-IIS/7.0
Date: Fri, 23 Jan 2009 03:55:39 GMT

You can see here from the Content-Type that this is an image. You can use HTTPClient from Apache from Java to do the HTTP Head request.

If you want to download the content for sure, then just issue the HTTP GET (using Httpclient) and use the same HTTP Header to determine the content type.