src/main/java/org/codelibs/fess/
├── FessBoot.java              # Application entry point
├── app/
│   ├── web/                   # User-facing controllers
│   ├── web/admin/             # Admin controllers
│   ├── service/               # Business logic
│   └── job/                   # Background jobs
├── api/                       # REST API endpoints
├── opensearch/                # OpenSearch integration

/**
 * Java 5 annotation for describing service layer security attributes.
 *
 * <p>
 * The <code>Secured</code> annotation is used to define a list of security configuration
 * attributes for business methods.
 * <p>
 * For example:
 *
 * <pre>
 * &#064;Secured({ &quot;ROLE_USER&quot; })
 * public void create(Contact contact);
 *
 * &#064;Secured({ &quot;ROLE_USER&quot;, &quot;ROLE_ADMIN&quot; })

            public void callback() {
                runnable.run();
            }

            @Override
            public boolean asPrimary() {
                return true; // mail is primary business
            }
        });
    }

    // ===================================================================================
    //                                                                       Resolve Label

    protected static final int HTTP_UNAUTHORIZED = 401;

    // ===================================================================================
    //                                                                    Business Failure
    //                                                                    ================
    @Override
    public ApiResponse handleValidationError(final ApiFailureResource resource) {