if (this.callbackHandler == null) {
throw new LoginException("no CallbackHandler available");
}
Callback[] callbacks = new Callback[]{
new CredentialsCallback()
};
this.principals.clear();
try {
//Calls setCredentials() on the callbacks
this.callbackHandler.handle(callbacks);
CredentialsCallback ccb = (CredentialsCallback) callbacks[0];
Credentials creds = ccb.getCredentials();
if (creds != null && creds instanceof SimpleCredentials) {
final SimpleCredentials sc = (SimpleCredentials) creds;