NTLM Authentication for currently logged in Windows user

[John . M . Corro-EXT]

I'm attempting to invoke an Integrated Authenticated protected web service 
from an applet in a Windows environment.  I'd like to make it such that 
the protected web services are invoked under the currently logged in 
user's credentials.  I understand that I have to supply an NTCredentials 
instance, but how can I do that dynamically and without explicitly asking 
the user or using hardcoded values?  That is, I'd like to dynamically get 
an instance of NTCredentials w/ the currently logged in user's 
username/password.

An additional challenge is that only *some* of the web services are 
Integrated Authentication protected.  It'd be much preferred if I could 
delegate the handling of whether a WS is protected or not to the 
HTTPClient instance.  In other words, I'd like to always invoke a given 
web service the same way and let HTTPClient figure out the rest.  Is this 
possible?

Here's some of the code I've been trying to get working:

// Configure connection settings
HttpClient httpClient = new HttpClient();
String host = ...;
httpClient.getHostConfiguration().setHost(host);

// Configure actual WS call
String webServicePath = ...;
PostMethod postMethod = new PostMethod(webServicePath);
postMethod.getHostAuthState().setAuthScheme(new NTLMScheme());
postMethod.setDoAuthentication(true);
byte[] xmlPayload = ...;
postMethod.setRequestEntity(new ByteArrayRequestEntity(xmlPayload));

try {
        httpClient.executeMethod(postMethod);
        if(postMethod.getStatusCode() == HttpStatus.SC_OK) {
                // Unmarshall returned XML
                ...
                ...
        }
} finally {
        postMethod.releaseConnection();
}


John M. Corro
(414) 524-7118