java - What is the proper way of setting headers in a URLConnection?

Question

My code is like the following:

URLConnection cnx = address.openConnection();
cnx.setAllowUserInteraction(false);         
cnx.setDoOutput(true);
cnx.addRequestProperty("User-Agent", 
    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)");
InputStream is = cnx.getInputStream();

Is it ok if I set the headers before I get the InputStream? Will my header be sent, or will the server see the default URLConnection's user-agent ( if any ) ?

Answer 1

The headers must be set prior to getting the InputStream to have any affect - an IllegalStateException will be thrown if the connection is already open.

As far as the User-Agent header specifically, it should be sent if it has been set.

See the URLConnection JavaDoc.