String sessionId = crawler.execute();
        System.out.println("Crawling completed. Session ID: " + sessionId);
    }
}
```

### File System Crawling

```java
import org.codelibs.fess.crawler.client.fs.FileSystemClient;

// Configure for file system crawling
container.singleton("fsClient", FileSystemClient.class);

// Add file URL
crawler.addUrl("file:///path/to/directory");

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.crawler.client.fs;

import java.io.File;
import java.util.Date;
import java.util.Set;

import org.codelibs.core.io.InputStreamUtil;
import org.codelibs.core.io.ResourceUtil;
import org.codelibs.fess.crawler.Constants;

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.crawler.client.fs;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URI;

import org.codelibs.core.io.ResourceUtil;
import org.codelibs.fess.crawler.client.CrawlerClientFactory;
import org.codelibs.fess.crawler.client.FaultTolerantClient;
import org.codelibs.fess.crawler.client.fs.FileSystemClient;
import org.codelibs.fess.crawler.client.http.HcHttpClient;
import org.codelibs.fess.crawler.container.StandardCrawlerContainer;
import org.codelibs.fess.crawler.entity.AccessResultImpl;