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

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遥遥无期
遥遥无期 2021-01-18 15:06

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

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  • 2021-01-18 15:10

    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.

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  • 2021-01-18 15:10

    This is a solution without apache.

    HttpURLConnection urlConnection;
    String urlString = "http://www.youtube.com/v/oHg5SJYRHA0";
    try {
        urlConnection = (HttpURLConnection) new URL(urlString).openConnection();
        urlConnection.setInstanceFollowRedirects(true);
        HttpURLConnection.setFollowRedirects(true);
    
        int status = urlConnection.getResponseCode();
        if (status >= 300 && status <= 307) {
            urlString = urlConnection.getHeaderField("Location");
            urlConnection = (HttpURLConnection) new URL(urlString).openConnection();
            System.out.println("Redirect to URL : " + urlString);
        }
        String contentType = urlConnection.getHeaderField("Content-Type");
        if (contentType.startsWith("image/")) {
            //do something with an image
        } else if (contentType.equals("application/x-shockwave-flash")) {
            //do something with a video
            //} else ...
        }
        System.out.println(contentType);
    } catch (IOException e) {
        e.printStackTrace();
    }
    

    Follow Redirect Example from mkyong.com

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  • 2021-01-18 15:15

    You can fetch the URL and see Content-type from the response.

    You can use the HTTP Client from apache, it helps you to fetch the content of the URL and you can use it to navigate the redirects. For instance try to fetch the following:

    http://www.youtube.com/watch?v=d4LkTstvUL4

    Will return an HTML containing the video. After a while you'll find out the video is here:

    http://www.youtube.com/v/d4LkTstvUL4

    But if you fetch that page you will get a redirect:

    HTTP/1.0 302 Redirect
    Date: Fri, 23 Jan 2009 02:25:37 GMT
    Content-Type: text/plain
    Expires: Fri, 23 Jan 2009 02:25:37 GMT
    Cache-Control: no-cache
    Server: Apache
    X-Content-Type-Options: nosniff
    Set-Cookie: VISITOR_INFO1_LIVE=sQc75zc-QSU; path=/; domain=.youtube.com; expires=
    Set-Cookie: VISITOR_INFO1_LIVE=sQc75zc-QSU; path=/; domain=.youtube.com; expires=
    Location: http://www.youtube.com/swf/l.swf?swf=http%3A//s.ytimg.com/yt/swf/cps-vf
    L4&rel=1&eurl=&iurl=http%3A//i1.ytimg.com/vi/d4LkTstvUL4/hqdefault.jpg&sk=Z_TM3JF
    e_get_video_info=1&load_modules=1
    

    So, what you have to do is to fetch the URL and examine it, until you get final content

    This section explains how to handle the redirects.

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  • 2021-01-18 15:23

    Hit the link and inspect the content type header? If the result is a HTML page you could look for the largest image or embedded flash file on the page and choose to display that?

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  • 2021-01-18 15:25

    I suggest using curl with a range header to allow you to inspect the file type itself.

    curl -s -v -r0-499 -o test  http://stackoverflow.com/content/img/so/logo.png
    * About to connect() to stackoverflow.com port 80 (#0)
    *   Trying 69.59.196.211... connected
    * Connected to stackoverflow.com (69.59.196.211) port 80 (#0)
    > GET /content/img/so/logo.png HTTP/1.1
    > Range: bytes=0-499
    > User-Agent: curl/7.19.4 (i386-apple-darwin9.6.0) libcurl/7.19.4 zlib/1.2.3
    > Host: stackoverflow.com
    > Accept: */*
    > 
    < HTTP/1.1 206 Partial Content
    < Cache-Control: max-age=604800
    < Content-Type: image/png
    < Content-Range: bytes 0-499/3438
    < Last-Modified: Fri, 05 Jun 2009 06:52:35 GMT
    < Accept-Ranges: bytes
    < ETag: "25dd4b35aae5c91:0"
    < Server: Microsoft-IIS/7.0
    < Date: Fri, 19 Jun 2009 19:39:43 GMT
    < Content-Length: 500
    < 
    { [data not shown]
    * Connection #0 to host stackoverflow.com left intact
    * Closing connection #0
    

    Then execute:

    $ file test
    test: PNG image data, 250 x 61, 8-bit colormap, non-interlaced
    

    Now you know the mime type: image/png, the file size 3438 bytes, and the file is a 250 x 61 color PNG image.

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  • 2021-01-18 15:34

    Fast video indexer is a video capture software that can capture video frames automatically from a list of videos and create index web pages, index pictures or a list of images.

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