@Override
 public void handle(Callback[] callbacks) throws IOException, UnsupportedCallbackException {
   for (Callback callback : callbacks) {
     if (callback instanceof NameCallback) {
       NameCallback nameCallback = (NameCallback) callback;
       nameCallback.setName("user");
     } else if (callback instanceof PasswordCallback) {
       PasswordCallback passwordCallback = (PasswordCallback) callback;
       passwordCallback.setPassword(password.toCharArray());
     } else if (callback instanceof AuthorizeCallback) {
       AuthorizeCallback authorizeCallback = (AuthorizeCallback) callback;
       authorizeCallback.setAuthorized(
           authorizeCallback
               .getAuthenticationID()
               .equals(authorizeCallback.getAuthorizationID()));
     } else if (callback instanceof RealmCallback) {
       RealmCallback realmCallback = (RealmCallback) callback;
       realmCallback.setText(REALM);
     } else {
       throw new UnsupportedCallbackException(callback);
     }
   }
 }