Url Validator

check_url.java

    /**
     * Recursive method for resolving redirects. Resolves at most MAX_REDIRECTS times.
     *
     * @param url                a URL
     * @param remainingRedirects loop counter
     * @return instance of URLConnection
     * @throws IOException if connection fails
     */
    protected boolean createConnection(URL url, int remainingRedirects) throws IOException {
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        setConnectionProperties(connection);

        int code = connection.getResponseCode();
        if (code == HttpURLConnection.HTTP_MOVED_PERM ||
                code == HttpURLConnection.HTTP_MOVED_TEMP ||
                code == HttpURLConnection.HTTP_SEE_OTHER) {

            if (remainingRedirects > 0) {
                // Stop redirecting.
                URL movedUrl = new URL(connection.getHeaderField("Location"));
                if (!url.getProtocol().equals(movedUrl.getProtocol())) {
                    // HttpURLConnection doesn't handle redirects across schemes, so handle it manually, see
                    // http://code.google.com/p/android/issues/detail?id=41651
                    connection.disconnect();
                    return createConnection(movedUrl, --remainingRedirects); // Recursion
                }
            }


        }
        int code2 = connection.getResponseCode();
        boolean result = code2 == 200;
        connection.disconnect();
        return result;
    }