*
 * @author higa
 */
public abstract class PropertiesUtil {

    /**
     * Do not instantiate.
     */
    protected PropertiesUtil() {
    }

    /**
     * Wraps exception handling for {@link Properties#load(InputStream)}.
     * <p>
     * The input stream is not closed.
     * </p>
     *
     * @param props the property set (must not be {@literal null})

import org.lastaflute.web.response.StreamResponse;

import jakarta.annotation.Resource;

/**
 * Action class for handling document redirection requests.
 * This action processes "go" requests that redirect users to specific documents
 * while tracking click events and handling various URL types including file system paths.
 */
public class GoAction extends FessSearchAction {

    /**

import org.codelibs.core.exception.NoSuchAlgorithmRuntimeException;

/**
 * Utility for handling {@link MessageDigest}.
 *
 * @author higa
 * @author shinsuke
 */
public abstract class MessageDigestUtil {

    /**
     * Do not instantiate.
     */
    protected MessageDigestUtil() {
    }

    /**
     * Wraps the exception handling of {@link MessageDigest#getInstance(String)}.
     *
     * @param algorithm

import org.codelibs.fess.util.ComponentUtil;

/**
 * Interface for transforming and processing crawled documents in Fess.
 * Provides utility methods for URL processing, site extraction, data mapping,
 * and field configuration handling during the document transformation process.
 */
public interface FessTransformer {

    /**
     * Synchronized LRU cache for storing parent URL encodings.

    @Resource
    protected ActivityHelper activityHelper;

    /** Manager for handling HTTP response operations. */
    @Resource
    protected ResponseManager responseManager;

    /** Time manager for handling date and time operations. */
    @Resource
    protected TimeManager timeManager;

    /** System helper for various system-level operations. */
    @Resource

import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

import org.codelibs.core.exception.IORuntimeException;
import org.codelibs.core.log.Logger;

/**
 * Utility class for handling {@link java.util.zip.ZipInputStream}.
 *
 * @author koichik
 */
public abstract class ZipInputStreamUtil {

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

    /**

- **I/O Operations** (`org.codelibs.core.io`) - File handling, resource management, stream utilities, and traversal utilities for efficient resource processing
- **Reflection** (`org.codelibs.core.lang`) - Class loading, method/field access, type introspection utilities, and generics support
- **Exception Handling** (`org.codelibs.core.exception`) - Runtime exception wrappers for common checked exceptions with consistent error handling

### Modern Java 21 Support

/**
 * Abstract base class for Fess API actions that provides common functionality
 * for API endpoints including authentication, message handling, and access control.
 *
 * This class extends FessBaseAction and provides specialized behavior for API requests,
 * including token-based authentication and JSON response handling.
 */
public abstract class FessApiAction extends FessBaseAction {

    /**
     * Default constructor.
     */

        assertNotNull(result);
        assertTrue(result.contains("3 docs"));
        // queryBuilder field is protected, so we can't directly assert it
    }

    // Test execute() method with exception handling
    public void test_execute_withException() {
        // Register a mock that throws exception
        SearchEngineClient exceptionClient = new SearchEngineClient() {
            @Override

/**
 * Fess-specific action validator that extends the LastaFlute ActionValidator.
 * 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> {

    /**