*
 * @since 1.0
 */
public abstract class FessBaseAction extends TypicalAction // has several interfaces for direct use
        implements LaValidatable<FessMessages>, FessHtmlPath {

    /**
     * Default constructor.
     */
    public FessBaseAction() {
        super();
    }

├── Constants.java             # Central application constants
├── app/
│   ├── web/                   # Controllers (Actions)
│   │   ├── base/              # Base action classes (FessBaseAction, FessAdminAction)
│   │   ├── admin/             # Admin controllers ({feature}/ with Action, Forms)
│   │   └── api/               # API controllers
│   ├── service/               # Business logic services

 * label management, user authentication, and search result processing.
 *
 * This class extends FessBaseAction and serves as the foundation for all search-related
 * web actions in the application.
 */
public abstract class FessSearchAction extends FessBaseAction {

    /**
     * Default constructor.
     */
    public FessSearchAction() {
        super();
    }

 * <p>
 * This abstract class provides common functionality for all admin actions,
 * including authentication, authorization, and HTML data setup.
 * </p>
 *
 */
public abstract class FessAdminAction extends FessBaseAction {

    /** Constant suffix for view names. */
    public static final String VIEW = "-view";

    /**
     * Default constructor.
     */
    public FessAdminAction() {
        super();
    }