import org.codelibs.fess.crawler.util.AccessResultCallback;

/**
 * Interface for data service operations related to access results.
 *
 * @param <RESULT> the type of access result
 */
public interface DataService<RESULT extends AccessResult<?>> {

    /**
     * Stores the given access result.
     *
     * @param accessResult the access result to store
     */
    void store(RESULT accessResult);

    /**

        dataService.delete("id1");

        assertNull(dataService.getAccessResult("id1", "http://www.id1.com/"));
        assertNotNull(dataService.getAccessResult("id2", "http://www.id2.com/"));

        dataService.store(accessResult1);
        assertNotNull(dataService.getAccessResult("id1", "http://www.id1.com/"));

        dataService.deleteAll();

        accessResult1.setUrl("http://www.id1.com/");

        dataService.store(accessResult1);

        final AccessResult accessResult2 = dataService.getAccessResult("id1", "http://www.id1.com/");
        assertNotNull(accessResult2);

        accessResult2.setMimeType("text/html");
        dataService.update(accessResult2);

        final AccessResult accessResult3 = dataService.getAccessResult("id1", "http://www.id1.com/");

import jakarta.annotation.Resource;

public class CrawlerTest extends LastaDiTestCase {

    @Resource
    private Crawler crawler;

    @Resource
    private DataService dataService;

    @Resource
    private UrlQueueService urlQueueService;

    @Resource
    private FileTransformer fileTransformer;

    @Resource
    private CrawlerContainer crawlerContainer;

    @Override

import org.codelibs.fess.crawler.util.CrawlerWebServer;
import org.dbflute.utflute.core.PlainTestCase;

public class CrawlerTest extends PlainTestCase {

    public Crawler crawler;

    public DataService dataService;

    public UrlQueueService urlQueueService;

    public FileTransformer fileTransformer;

    private StandardCrawlerContainer container;

    @Override
    protected void setUp() throws Exception {

     * Otherwise, it sets the provided DataService to the current thread's local storage.
     *
     * @param dataService the DataService instance to be set for the current thread, or null to remove it
     */
    public static void setDataService(final DataService<AccessResult<?>> dataService) {
        if (dataService == null) {
            DATA_SERVICE_THREAD_LOCAL.remove();

            }

            dataService.iterate(sessionId1, accessResult -> assertTrue(accessResult.getUrl().startsWith(url1)));
            dataService.iterate(sessionId2, accessResult -> assertTrue(accessResult.getUrl().startsWith(url2)));

            dataService.delete(sessionId1);
            dataService.delete(sessionId2);
        } finally {
            try {

    }

    // Test run method with null DataService
    public void test_run_nullDataService() {
        indexUpdater.dataService = null;
        try {
            indexUpdater.run();
            fail("Should throw FessSystemException");
        } catch (FessSystemException e) {
            assertEquals("DataService is null.", e.getMessage());
        }
    }

crawler.addUrl("https://example.com/sitemap.xml");
```

## Data Access and Storage

### Accessing Crawled Data

```java
// Get data service
DataService dataService = container.getComponent("dataService");

// Iterate through crawled data
dataService.iterate(sessionId, accessResult -> {
    System.out.println("URL: " + accessResult.getUrl());
    System.out.println("Status: " + accessResult.getHttpStatusCode());

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

    /**
     * Data service for checking access results.
     */
    @Resource
    protected OpenSearchDataService dataService;

    /**
     * Cache for session queues.
     */
    protected Map<String, QueueHolder> sessionCache = new ConcurrentHashMap<>();

    /**
     * The number of URLs to fetch when polling.
     */