etUserPrincipal</code>, <code>getRemoteUser</code>, and <code>getAuthType</code>. Return <code>false</code> if
 authentication is incomplete and the underlying login mechanism has committed, in the response, the message (e.g.,
 challenge) and HTTP status code to be returned to the user.</dd>
<dt>Throws:</dt>
<dd><code><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/io/IOException.html" title="class or interface in java.io" class="external-link">IOException</a></code> - if an input