can I check if a file exists at a URL?

Question

This link is very good for C#, what about java. I serach but i did not find good solution.

score 12 · Accepted Answer · 2013-03-06T12:23:31.950

12

It's quite similar in Java. You just need to evaluate the HTTP Response code:

final URL url = new URL("http://some.where/file.html");
url.openConnection().getResponseCode();

A more complete example can be found here.

edited Mar 06 '13 at 12:23

answered Mar 17 '10 at 11:55

2

I just wanted to note that some websites will not actually return a 404 status code, but rather redirect to a custom error page (and return 200 Successful). This is bad behavior, but it is worth ensuring that the site you are testing against isn't serving up these "soft" 404s. – Kris Mar 17 '10 at 12:37
1) You may want to catch `UnknownHostException` and `FileNotFoundException` on `openConnection()` method (both just `IOException`). 2) You also want to cast the `URLConnection` down to `HttpURLConnection` to be able to call the `getResponseCode()` method. And @Kris: a redirect would result in a 301 or 302 which you need to handle at any way. The URL might for instance have been updated. – BalusC Mar 17 '10 at 12:56
Also if the file is quite large you'll end up downloading the entire content to check for existence. If you issue a HEAD request instead of a GET you'll get better mileage. – Raymond Kroeker Apr 11 '10 at 18:34

score 5 · Answer 2 · answered Jun 17 '11 at 03:40

Contributing a clean version that's easier to copy and paste.

try {
    final URL url = new URL("http://your/url");
    HttpURLConnection huc = (HttpURLConnection) url.openConnection();
    int responseCode = huc.getResponseCode();
    // Handle response code here...
} catch (UnknownHostException uhe) {
    // Handle exceptions as necessary
} catch (FileNotFoundException fnfe) {
    // Handle exceptions as necessary
} catch (Exception e) {
    // Handle exceptions as necessary
}

can I check if a file exists at a URL?

2 Answers2