private final transient VaMessenger<FessMessages> messageCode;

    /**
     * Creates a new InvalidQueryException with message code, message, and cause.
     *
     * @param messageCode the message code for localized error messages
     * @param message the detailed error message
     * @param cause the cause of the exception
     */

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.exception;

import org.codelibs.fess.mylasta.action.FessMessages;
import org.lastaflute.web.validation.VaMessenger;

/**
 * Exception thrown during SSO (Single Sign-On) processing with message code support.
 *

        assertEquals("{errors.front_footer}", FessMessages.ERRORS_front_footer);
        assertEquals("{errors.front_prefix}", FessMessages.ERRORS_front_prefix);
        assertEquals("{errors.front_suffix}", FessMessages.ERRORS_front_suffix);
        assertEquals("{errors.header}", FessMessages.ERRORS_HEADER);
        assertEquals("{errors.footer}", FessMessages.ERRORS_FOOTER);

        final List<VaMessenger<FessMessages>> errorMessages = new ArrayList<>();
        AdminSearchlistAction.validateFields(doc, errorMessages::add);

        assertFalse(errorMessages.isEmpty());

        // Verify error messages use field names without doc. prefix
        final FessMessages messages = new FessMessages();
        errorMessages.forEach(m -> m.message(messages));

    @Override
    public ActionValidator<FessMessages> createValidator() {
        return systemHelper.createValidator(requestManager, this::createMessages, myValidationGroups());
    }

    /**
     * Creates a new messages instance for handling validation and user messages.
     * This method can be called by the application to create message containers.
     *
     * @return a new FessMessages instance
     */
    @Override

     * @return concatenated string of localized validation messages separated by spaces
     */
    protected String getMessage(final VaMessenger<FessMessages> validationMessagesLambda) {
        final FessMessages messages = new FessMessages();
        validationMessagesLambda.message(messages);
        return messageManager.toMessageList(request.getLocale() == null ? Locale.ENGLISH : request.getLocale(), messages)

* [fess_label_en.properties](https://github.com/codelibs/fess/blob/master/src/main/resources/fess_label_en.properties)
* [fess_message_en.properties](https://github.com/codelibs/fess/blob/master/src/main/resources/fess_message_en.properties)

     * Adds a password validation error message to the messages object based on the error key.
     *
     * @param messages the FessMessages object to add the error to
     * @param errorKey the error key identifying the type of password validation error
     */
    protected void addPasswordValidationError(final FessMessages messages, final String errorKey) {
        switch (errorKey) {
        case "errors.password_length":

* [fess_label_en.properties](https://github.com/codelibs/fess/blob/master/src/main/resources/fess_label_en.properties)
* [fess_message_en.properties](https://github.com/codelibs/fess/blob/master/src/main/resources/fess_message_en.properties)

         * @return This ApiErrorResponse instance.
         */
        public ApiErrorResponse message(final VaMessenger<FessMessages> validationMessagesLambda) {
            final FessMessages messages = new FessMessages();
            validationMessagesLambda.message(messages);
            message = ComponentUtil.getMessageManager()