Re: The simplest way to download a file from http resource that need authentication

=?UTF-8?B?QXJuZSBWYWpow7hq?= <>
Sat, 09 Feb 2008 19:09:53 -0500
Andrea Francia wrote:

Lew wrote:

Andrea Francia wrote:

Authenticator.setDefault() method which is a static method and therefore
not usable in a threaded enviroment.

Static methods can be used in a multi-threaded program.

There is a race conditions. Here the example:

We have two thread: t1 and t2 that executes the following code

    Authenticator.setDefault(new Authenticator() {
      protected PasswordAuthentication getPasswordAuthentication() {
         return new PasswordAuthentication(username,
    URLConnection con = url.openConnection();

Authenticator.setDefault is designed for proxy servers that
requires authentication and in that context all requests
need the same authenticator.

I think you will need to set HTTP headers manually.

Something like:

con.setRequestProperty ("Authorization", "Basic " +


     public static String basicauth(String un, String pw) throws
MessagingException, IOException {
         ByteArrayOutputStream baos = new ByteArrayOutputStream();
         OutputStream b64os = MimeUtility.encode(baos, "base64");
         b64os.write((un + ":" + pw).getBytes());
         return new String(baos.toByteArray());


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