- Return `HtmlResponse` for JSP, `JsonResponse` for APIs

### Service
- Inject behaviors (Bhv) for data access
- Use `OptionalEntity<T>` for nullable returns
- Plain classes (no extends/implements)

### Helper
- Stateless utility classes
- Access via `ComponentUtil.getXyzHelper()`
- Named with "Helper" suffix

### DBFlute Generated Code
```
opensearch/{index}/

@GwtIncompatible
// TODO(b/278589132): Remove the redundant "@NonNull" on B once it's no longer required by J2KT.
public final class ImmutableClassToInstanceMap<B>
    extends ForwardingMap<Class<? extends @NonNull B>, B>
    implements ClassToInstanceMap<B>, Serializable {

  private static final ImmutableClassToInstanceMap<Object> EMPTY =
      new ImmutableClassToInstanceMap<>(ImmutableMap.of());

  /**

 *
 * This command is used to read data from a file that has been
 * previously opened with a Create request.
 *
 * @author mbechler
 */
public class Smb2ReadRequest extends ServerMessageBlock2Request<Smb2ReadResponse> implements RequestWithFileId {

    /**
     * Flag to indicate unbuffered read operation
     */
    public static byte SMB2_READFLAG_READ_UNBUFFERED = 0x1;
    /**
     * Channel type for standard read without RDMA

import org.slf4j.LoggerFactory;

/**
 * Mock witness service for integration testing.
 * Simulates a basic witness service that can accept registrations
 * and send notifications.
 */
public class MockWitnessService implements AutoCloseable {
    private static final Logger log = LoggerFactory.getLogger(MockWitnessService.class);

    private ServerSocket serverSocket;
    private final AtomicBoolean running = new AtomicBoolean(false);

        when(parentLocator.isWorkgroup()).thenReturn(true);
    }

    /** Simple implementation of FileEntry for controlled inputs in tests. */
    private static final class StubFileEntry implements FileEntry {
        private final String name;
        private final int type;

        StubFileEntry(String name, int type) {
            this.name = name;
            this.type = type;
        }

 *
 * @deprecated since 4.0.0, use {@link org.apache.maven.api.services.SettingsBuilder} instead
 */
@Named
@Singleton
@Deprecated(since = "4.0.0")
public class DefaultSettingsBuilder implements SettingsBuilder {

    private SettingsReader settingsReader;

    private SettingsWriter settingsWriter;

    private SettingsValidator settingsValidator;

import org.codelibs.fess.opensearch.config.exentity.DataConfig;
import org.codelibs.fess.util.ComponentUtil;

/**
 * The abstract class for DataStore.
 */
public abstract class AbstractDataStore implements DataStore {

    private static final Logger logger = LogManager.getLogger(AbstractDataStore.class);

    /**
     * The script type.
     */
    protected static final String SCRIPT_TYPE = "script_type";

     * the URL string and performs minimal validation – just enough to make the
     * happy-path expectations deterministic.
     */
    private static class DummySmbResourceLocator implements SmbResourceLocator {
        private final String urlStr;
        private final String host;
        private final String path;
        private final String canonical;
        private DfsReferralData dfsReferral;

        }

        private static class DefaultArtifactFactoryRequestArtifact extends BaseRequest<Session>
                implements ArtifactCoordinatesFactoryRequest {
            private final String groupId;
            private final String artifactId;
            private final String version;
            private final String classifier;

		}
	}
	return err
}

// MarshalMsg implements msgp.Marshaler
func (z dataUsageHashMap) MarshalMsg(b []byte) (o []byte, err error) {
	o = msgp.Require(b, z.Msgsize())
	o = msgp.AppendArrayHeader(o, uint32(len(z)))
	for zb0004 := range z {
		o = msgp.AppendString(o, zb0004)
	}
	return o, err
}

// UnmarshalMsg implements msgp.Unmarshaler