- Graceful degradation (e.g., robots.txt parsing continues on errors)

---

## Key Components

### Crawler (`Crawler.java`)

Main orchestrator for crawling operations.

**Key Methods**:
```java
String execute()                // Start crawling, return session ID
void addUrl(String url)         // Add URL to queue
void cleanup(String sessionId)  // Clean up session

 *
 */
public class AdminRoleAction extends FessAdminAction {

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

    /** Role name for admin role operations */
    public static final String ROLE = "admin-role";

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

import org.codelibs.fess.crawler.exception.CrawlerSystemException;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.helpers.DefaultHandler;

/**
 * Utility class for XML-related operations.
 *
 * This class provides methods to escape special characters in XML strings,
 * strip invalid XML characters, and parse XML content into a map of data.
 *
 * <p>
 * The class is final and cannot be instantiated.

    // ===================================================================================
    // Attribute
    // =========
    /** The search helper for performing search operations. */
    @Resource
    protected SearchHelper searchHelper;

    /** The search engine client for interacting with OpenSearch. */
    @Resource
    protected SearchEngineClient searchEngineClient;

        assertTrue(stats.getIntegerOverflowsPrevented() > 0);
    }

    @Test
    public void testBoundaryValues() throws Exception {
        // Test boundary values for safe operations
        assertEquals(Integer.MAX_VALUE, validator.safeAdd(Integer.MAX_VALUE, 0));
        assertEquals(Integer.MIN_VALUE, validator.safeAdd(Integer.MIN_VALUE, 0));

        byte[] readFileId = new byte[16];
        System.arraycopy(buffer, 8, readFileId, 0, 16);
        assertArrayEquals(nullFileId, readFileId);
    }

    @Test
    @DisplayName("Should handle sequential operations")
    void testSequentialOperations() {
        // Given
        request.setNotifyFlags(0);
        request.setCompletionFilter(0);

        // When - first write
        byte[] buffer1 = new byte[512];

   */
  RangeSet<C> complement();

  /**
   * Returns a view of the intersection of this {@code RangeSet} with the specified range.
   *
   * <p>The returned view supports all optional operations supported by this {@code RangeSet}, with
   * the caveat that an {@link IllegalArgumentException} is thrown on an attempt to {@linkplain
   * #add(Range) add} any range not {@linkplain Range#encloses(Range) enclosed} by {@code view}.

public class AdminSysteminfoAction extends FessAdminAction {

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

    /** Role name for admin system info operations */
    public static final String ROLE = "admin-systeminfo";

    private static final String MASKED_VALUE = "XXXXXXXX";

    // ===================================================================================

   * #descendingMultiset()} will not reflect any changes you make to the behavior of methods such as
   * {@link #add(Object)} or {@link #pollFirstEntry}. This skeleton implementation correctly
   * delegates each of its operations to the appropriate methods of this {@code
   * ForwardingSortedMultiset}.
   *
   * <p>In many cases, you may wish to override {@link #descendingMultiset()} to return an instance

    private volatile Thread thread;
    private volatile TransportException te;

    /**
     * Lock object for synchronizing input operations
     */
    protected final Object inLock = new Object();
    /**
     * Lock object for synchronizing output operations
     */
    protected final Object outLock = new Object();

    /**
     * Map for tracking pending responses by their key
     */