messages.add(message);
    }

    @Override
    public String toString() {
        return render("");
    }

    public String render(String indentation) {
        if (messages.isEmpty()) {
            return indentation + "There were no validation errors.";
        }

        StringBuilder message = new StringBuilder();
        for (int i = 0; i < messages.size(); i++) {

                logger.warn("Failed to process a request.", e);
                throwValidationErrorApi(messages -> messages.addErrorsCrudFailedToCreateCrudTable(GLOBAL, buildThrowableMessage(e)));
            }
            return entity;
        }).orElseGet(() -> {
            throwValidationErrorApi(messages -> messages.addErrorsCrudFailedToCreateInstance(GLOBAL));
            return null;
        });

                logger.warn("Failed to process a request.", e);
                throwValidationErrorApi(messages -> messages.addErrorsCrudFailedToCreateCrudTable(GLOBAL, buildThrowableMessage(e)));
            }
            return entity;
        }).orElseGet(() -> {
            throwValidationErrorApi(messages -> messages.addErrorsCrudFailedToCreateInstance(GLOBAL));
            return null;
        });

    private static final long serialVersionUID = 1L;

    /** Message code for localized error messages */
    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
     */

     * @param validationMessagesLambda lambda function that adds validation messages
     * @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);

                logger.warn("Failed to process a request.", e);
                throwValidationError(messages -> messages.addErrorsFailedToUploadMappingFile(GLOBAL),
                        () -> redirectWith(getClass(), moreUrl("uploadpage/" + form.dictId)));
            }
            saveInfo(messages -> messages.addSuccessUploadMappingFile(GLOBAL));

 * This validator provides validation functionality for Fess web actions with custom
 * message handling and runtime group validation.
 *
 * @param <MESSAGES> the type of user messages used by this validator
 */
public class FessActionValidator<MESSAGES extends UserMessages> extends ActionValidator<MESSAGES> {

    /**
     * Constructs a new FessActionValidator with the specified components.
     *

                throwValidationErrorApi(messages -> {
                    messages.addErrorsFailedToStartJob(GLOBAL, entity.getName());
                });
            }
            try {
                entity.start();
            } catch (final Exception e) {
                throwValidationErrorApi(messages -> {
                    messages.addErrorsFailedToStartJob(GLOBAL, entity.getName());
                });

            if (logger.isDebugEnabled()) {
                logger.debug("Invalid offset: {}", form.offset, e);
            }
            throwValidationError(messages -> messages.addErrorsResultSizeExceeded(GLOBAL), this::asListHtml);
        }

        throwValidationError(messages -> messages.addErrorsInvalidQueryUnknown(GLOBAL), this::asListHtml);
        return null; // ignore
    }

    /**

    }

    /**
     * Saves error messages to the session.
     * The messages will be displayed to the user on the next page load.
     *
     * @param validationMessagesLambda a lambda function to configure the error messages
     */
    protected void saveError(final VaMessenger<FessMessages> validationMessagesLambda) {
        final FessMessages messages = createMessages();