- ✅ Whitespace and empty string handling

---

### 3. ArchiveExtractorErrorHandlingTest.java
**Purpose**: Test improved error handling in archive extractors.

**Key Test Areas**:
- Enhanced error messages
- Partial extraction (continues on failure)
- Invalid archive handling
- Empty archive handling
- Mixed valid/invalid entries

**Covered Extractors**:
- ZipExtractor
- TarExtractor

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);

    /**

    @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 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 {

    /**

- `CurlRequestTest`: Tests for request builder, headers, parameters, body content, SSL, proxies, timeouts
- `CurlResponseTest`: Tests for response handling, status codes, content retrieval, resource management
- `CurlExceptionTest`: Tests for exception handling and error scenarios

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.

   * Test EqualsTester with no equals or not equals objects. This checks proper handling of null,
   * incompatible class and reflexive tests
   */
  public void testTestEqualsEmptyLists() {
    equalsTester.addEqualityGroup(reference);
    equalsTester.testEquals();
  }

  /**
   * Test EqualsTester after populating equalObjects. This checks proper handling of equality and
   * verifies hashCode for valid objects
   */

   * Test EqualsTester with no equals or not equals objects. This checks proper handling of null,
   * incompatible class and reflexive tests
   */
  public void testTestEqualsEmptyLists() {
    equalsTester.addEqualityGroup(reference);
    equalsTester.testEquals();
  }

  /**
   * Test EqualsTester after populating equalObjects. This checks proper handling of equality and
   * verifies hashCode for valid objects
   */

/**
 * 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.
     */