}
}
```

### 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");
crawler.urlFilter.addInclude("file:///path/to/directory/.*");
```

## Configuration

### XML Configuration

Shinsuke Sugaya <******@****.***> 1774681159 +0900

  private var messageInflater: MessageInflater? = null

  // Masks are only a concern for server writers.
  private val maskKey: ByteArray? = if (isClient) null else ByteArray(4)
  private val maskCursor: Buffer.UnsafeCursor? = if (isClient) null else Buffer.UnsafeCursor()

  interface FrameCallback {
    @Throws(IOException::class)
    fun onReadMessage(text: String)

    @Throws(IOException::class)

  private val serverReader =
    WebSocketReader(
      isClient = false,
      source = data,
      frameCallback = callback.asFrameCallback(),
      perMessageDeflate = false,
      noContextTakeover = false,
    )
  private val serverReaderWithCompression =
    WebSocketReader(
      isClient = false,
      source = data,
      frameCallback = callback.asFrameCallback(),

var magicHighwayHash256Key = []byte("\x4b\xe7\x34\xfa\x8e\x23\x8a\xcd\x26\x3e\x83\xe6\xbb\x96\x85\x52\x04\x0f\x93\x5d\xa3\x9f\x44\x14\x97\xe0\x9d\x13\x22\xde\x36\xa0")

// Interface for elasticsearch client objects
type esClient interface {
	isAtleastV7() bool
	createIndex(ElasticsearchArgs) error
	ping(context.Context, ElasticsearchArgs) (bool, error)
	stop()
	entryExists(context.Context, string, string) (bool, error)

    }

    private EngineObj getEngineObj() {
        final EngineObj engineObj = new EngineObj();
        try {
            final SearchEngineClient esClient = ComponentUtil.getSearchEngineClient();
            final ClusterHealthResponse response =
                    esClient.admin().cluster().prepareHealth().execute().actionGet(fessConfig.getIndexHealthTimeout());
            engineObj.clusterName = response.getClusterName();

    client: Boolean,
  ) {
    val extensions = this.extensions!!
    synchronized(this) {
      this.name = name
      this.socket = socket
      this.writer =
        WebSocketWriter(
          isClient = client,
          sink = socket.sink,
          random = random,
          perMessageDeflate = extensions.perMessageDeflate,
          noContextTakeover = extensions.noContextTakeover(client),