Java - How to find the redirected url of a url?

Simply call getUrl() on URLConnection instance after calling getInputStream():

URLConnection con = new URL( url ).openConnection();System.out.println( "orignal url: " + con.getURL() );con.connect();System.out.println( "connected url: " + con.getURL() );InputStream is = con.getInputStream();System.out.println( "redirected url: " + con.getURL() );is.close();

If you need to know whether the redirection happened before actually getting it's contents, here is the sample code:

HttpURLConnection con = (HttpURLConnection)(new URL( url ).openConnection());con.setInstanceFollowRedirects( false );con.connect();int responseCode = con.getResponseCode();System.out.println( responseCode );String location = con.getHeaderField( "Location" );System.out.println( location );

You need to cast the URLConnection to HttpURLConnection and instruct it to not follow the redirects by setting HttpURLConnection#setInstanceFollowRedirects() to false. You can also set it globally by HttpURLConnection#setFollowRedirects().

You only need to handle redirects yourself then. Check the response code by HttpURLConnection#getResponseCode(), grab the Location header by URLConnection#getHeaderField() and then fire a new HTTP request on it.

public static URL getFinalURL(URL url) {    try {        HttpURLConnection con = (HttpURLConnection) url.openConnection();        con.setInstanceFollowRedirects(false);        con.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36");        con.addRequestProperty("Accept-Language", "en-US,en;q=0.8");        con.addRequestProperty("Referer", "https://www.google.com/");        con.connect();        //con.getInputStream();        int resCode = con.getResponseCode();        if (resCode == HttpURLConnection.HTTP_SEE_OTHER                || resCode == HttpURLConnection.HTTP_MOVED_PERM                || resCode == HttpURLConnection.HTTP_MOVED_TEMP) {            String Location = con.getHeaderField("Location");            if (Location.startsWith("/")) {                Location = url.getProtocol() + "://" + url.getHost() + Location;            }            return getFinalURL(new URL(Location));        }    } catch (Exception e) {        System.out.println(e.getMessage());    }    return url;}

To get "User-Agent" and "Referer" by yourself, just go to developer mode of one of your installed browser (E.g. press F12 on Google Chrome). Then go to tab 'Network' and then click on one of the requests. You should see it's details. Just press 'Headers' sub tab (the image below)