FULL PRODUCT VERSION :
java version "1.6.0_17"
Java(TM) SE Runtime Environment (build 1.6.0_17-b04)
Java HotSpot(TM) Client VM (build 14.3-b01, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.0.6000]

EXTRA RELEVANT SYSTEM CONFIGURATION :
Web server: IIS 6, Authentication digest, webservice - but test http connection only

A DESCRIPTION OF THE PROBLEM :
Try connect to service by url="http://server.net/service.asmx?WSDL"
Used: sun.net.www.protocol.http.HttpURLConnection
Result: <401: Unauthorized>

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
I run test with HttpURLConnection
HttpURLConnection: <200: OK> http://server.net/service.asmx
HttpURLConnection: <401: Unauthorized> http://server.net/service.asmx?WSDL

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
HttpURLConnection: <200: OK> http://server.net/service.asmx
HttpURLConnection: <200: OK> http://server.net/service.asmx?WSDL

like in web-browser - http header:
Authorization: Digest username="test", uri="/service.asmx", ....

http://www.ietf.org/rfc/rfc2617.txt "3.2.1 The WWW-Authenticate Response Header"
 reference to http://www.ietf.org/rfc/rfc2616.txt "3.2.2 http URL"
http_URL = "http:" "//" host [ ":" port ] [ abs_path [ "?" query ]]
ACTUAL -
HttpURLConnection: <200: OK> http://server.net/service.asmx
HttpURLConnection: <401: Unauthorized> http://server.net/service.asmx?WSDL

http header in second case:
Authorization: Digest username="test", uri="/service.asmx?WSDL",...

ERROR MESSAGES/STACK TRACES THAT OCCUR :
HttpURLConnection: <401: Unauthorized> http://server.net/service.asmx?WSDL
java.net.ProtocolException: Server redirected too many times (20)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at sun.net.www.protocol.http.HttpURLConnection$6.run(HttpURLConnection.java:1368)
at java.security.AccessController.doPrivileged(Native Method)
at sun.net.www.protocol.http.HttpURLConnection.getChainedException(HttpURLConnection.java:1362)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1016)
at java.net.URLConnection.getContent(URLConnection.java:688)
...

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
String userInfo = "test";
public void test() throws Exception {
        Authenticator.setDefault(new Authenticator() {
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication(userInfo,"test".toCharArray());
            }
        testURL(new URI("http://server.net/service.asmx"));
        testURLQuery(new URI("http://server.net/service.asmx?WSDL"));
        });
}

    private void testURL(URI targetURI) throws Exception {
        URI serviceURI = new URI(targetURI.getScheme(), userInfo, targetURI
                .getHost(), targetURI.getPort(), targetURI.getPath(), null,
                null);
        testConnection(serviceURI);
    }

    private void testURLQuery(URI targetURI) throws Exception {
        URI serviceURI = new URI(targetURI.getScheme(), userInfo, targetURI
                .getHost(), targetURI.getPort(), targetURI.getPath(), targetURI
                .getQuery(), null);
        testConnection(serviceURI);
    }

    private void testConnection(URI serviceURI) throws Exception {
        HttpURLConnection connection = (HttpURLConnection) serviceURI.toURL()
                .openConnection();
        int statusCode = connection.getResponseCode();
        logger.debug(String.format("HttpURLConnection: <%s: %s> %s", statusCode, connection.getResponseMessage(), serviceURI));
        connection.connect();
        connection.getContent();
    }
---------- END SOURCE ----------