* </pre>
 */
public class Crawler {

    /**
     * Creates a new instance of Crawler.
     */
    public Crawler() {
        // Default constructor
    }

    /** Logger instance for this class. */
    private static final Logger logger = LogManager.getLogger(Crawler.class);

    /** Thread name for web and file system crawling process. */

    OkHttpClient client = new OkHttpClient.Builder()
        .cache(cache)
        .callTimeout(5, TimeUnit.SECONDS)
        .build();

    Crawler crawler = new Crawler(client, queueLimit, hostLimit);
    crawler.queue.add(HttpUrl.get(args[1]));
    crawler.parallelDrainQueue(threadCount);
  }

        Crawler.Options options = new Crawler.Options();
        options.sessionId = "test-session";
        options.fileConfigIds = "file1";

        int result = crawler.doCrawl(options);
        assertEquals(Constants.EXIT_OK, result);
    }

    public void test_doCrawl_withDataConfigIds() {
        Crawler.Options options = new Crawler.Options();
        options.sessionId = "test-session";

 */
package org.codelibs.fess.crawler;

import java.io.File;

import org.codelibs.core.io.ResourceUtil;
import org.codelibs.fess.crawler.container.CrawlerContainer;
import org.codelibs.fess.crawler.entity.UrlQueue;
import org.codelibs.fess.crawler.filter.impl.UrlFilterImpl;
import org.codelibs.fess.crawler.service.DataService;
import org.codelibs.fess.crawler.service.UrlQueueService;

import org.codelibs.fess.crawler.filter.impl.UrlFilterImpl;
import org.codelibs.fess.crawler.service.DataService;
import org.codelibs.fess.crawler.service.UrlFilterService;
import org.codelibs.fess.crawler.service.UrlQueueService;
import org.codelibs.fess.crawler.transformer.impl.FileTransformer;
import org.codelibs.fess.crawler.util.CrawlerWebServer;
import org.codelibs.opensearch.runner.OpenSearchRunner;
import org.dbflute.utflute.lastadi.LastaDiTestCase;

});

Crawler crawler = container.getComponent("crawler");
crawler.addUrl("https://example.com");
crawler.crawlerContext.setMaxAccessCount(500);
String sessionId = crawler.execute();
```

### Background Crawling

```java
// Configure for background execution
crawler.setBackground(true);
String sessionId = crawler.execute();

// Check crawling status

import org.codelibs.core.lang.SystemUtil;
import org.codelibs.fess.crawler.Constants;
import org.codelibs.fess.crawler.CrawlerContext;
import org.codelibs.fess.crawler.container.CrawlerContainer;
import org.codelibs.fess.crawler.entity.AccessResult;
import org.codelibs.fess.crawler.entity.RequestData;
import org.codelibs.fess.crawler.entity.ResponseData;
import org.codelibs.fess.crawler.entity.ResultData;
import org.codelibs.fess.crawler.entity.UrlQueue;

import org.codelibs.fess.crawler.client.CrawlerClientFactory;
import org.codelibs.fess.crawler.container.CrawlerContainer;
import org.codelibs.fess.crawler.entity.AccessResult;
import org.codelibs.fess.crawler.entity.RequestData;
import org.codelibs.fess.crawler.entity.ResponseData;
import org.codelibs.fess.crawler.entity.UrlQueue;
import org.codelibs.fess.crawler.exception.ChildUrlsException;

import com.google.common.cache.LoadingCache;

import jakarta.annotation.PostConstruct;
import jakarta.annotation.PreDestroy;

/**
 * Helper class for managing crawler statistics and performance metrics.
 * This class provides functionality to track, record, and report statistics
 * about crawler operations including timing data, performance metrics, and
 * operational events. It uses an internal cache to maintain statistics

import org.codelibs.fess.crawler.Constants;
import org.codelibs.fess.crawler.builder.RequestDataBuilder;
import org.codelibs.fess.crawler.client.AbstractCrawlerClient;
import org.codelibs.fess.crawler.client.AccessTimeoutTarget;
import org.codelibs.fess.crawler.entity.RequestData;
import org.codelibs.fess.crawler.entity.ResponseData;
import org.codelibs.fess.crawler.exception.ChildUrlsException;