er. If the
 user has not been authenticated, the method returns null.</div>
<dl class="notes">
<dt>Returns:</dt>
<dd>a <code>java.security.Principal</code> containing the name of the user making this request; null if the user
 has not been authenticated</dd>
<dt>Throws:</dt>
<dd><code><a href="https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/IllegalStateException.html" title="class or interface in java.lang" class="external-link">IllegalStateException</a></code> - if called outside the