* </p>
 *
 * <pre>
 * {@code
 * FtpClient ftpClient = new FtpClient();
 * ftpClient.init(); // Initialize with configured parameters
 * ResponseData responseData = ftpClient.doGet("ftp://example.com/path/to/file.txt");
 * // Process the responseData
 * ftpClient.close(); // Close and release resources
 * }
 * </pre>
 *
 * @author shinsuke
 */
public class FtpClient extends AbstractCrawlerClient {

    /** Property name for time to live setting */
    public static final String TIME_TO_LIVE_PROPERTY = "timeToLive";

    /**
     * Constructs a new HcHttpClient.
     */
    protected HcHttpClient() {
        // Default constructor
    }

            public static final String FTP_AUTHENTICATIONS = FtpClient.FTP_AUTHENTICATIONS_PROPERTY;
            public static final String ROBOTS_TXT_ENABLED = HcHttpClient.ROBOTS_TXT_ENABLED_PROPERTY;
            public static final String PROXY_PASSWORD = "proxyPassword";
            public static final String PROXY_USERNAME = "proxyUsername";
            public static final String PROXY_PORT = HcHttpClient.PROXY_PORT_PROPERTY;

        if (StringUtil.isNotBlank(proxyHost) && StringUtil.isNotBlank(proxyPort)) {
            factoryParamMap.put(HcHttpClient.PROXY_HOST_PROPERTY, proxyHost);
            factoryParamMap.put(HcHttpClient.PROXY_PORT_PROPERTY, proxyPort);
            final String proxyUsername = paramMap.get(CRAWLER_WEB_PREFIX + "proxyUsername");

- `Crawler.java`, `CrawlerContext.java`, `CrawlerThread.java`

**Clients**: `fess-crawler/src/main/java/org/codelibs/fess/crawler/client/`
- `http/` - `HcHttpClient.java`, `Hc4HttpClient.java`, `Hc5HttpClient.java`, `SwitchableHttpClient.java`
- `fs/FileSystemClient.java`, `ftp/FtpClient.java`
- `smb/SmbClient.java`, `smb1/SmbClient.java`
- `storage/StorageClient.java`, `s3/S3Client.java`, `gcs/GcsClient.java`

    ```java
      private final OkHttpClient client = new OkHttpClient();

      public void run() throws Exception {
        Request request = new Request.Builder()
            .url("http://httpbin.org/delay/1") // This URL is served with a 1 second delay.
            .build();

        // Copy to customize OkHttp for this request.
        OkHttpClient client1 = client.newBuilder()

      )
    }
  }

  @Test fun testH2PriorKnowledgeOkHttpClientConstructionSuccess() {
    val okHttpClient =
      OkHttpClient
        .Builder()
        .protocols(listOf(Protocol.H2_PRIOR_KNOWLEDGE))
        .build()
    assertThat(okHttpClient.protocols.size).isEqualTo(1)
    assertThat(okHttpClient.protocols[0]).isEqualTo(Protocol.H2_PRIOR_KNOWLEDGE)
  }

  @Test fun nullDefaultProxySelector() {

    /**
     * Returns the [CookieJar] for the OkHttpClient, or an override from the Call.Chain.
     */
    val cookieJar: CookieJar

    /**
     * Returns a new chain with the specified [CookieJar].
     */
    fun withCookieJar(cookieJar: CookieJar): Chain

    /**
     * Returns the [Cache] for the OkHttpClient, or an override from the Call.Chain.
     */
    val cache: Cache?

 */
package okhttp3.recipes;

import java.io.IOException;
import java.util.concurrent.TimeUnit;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public final class PerCallSettings {
  private final OkHttpClient client = new OkHttpClient();

  public void run() throws Exception {
    Request request = new Request.Builder()

      }
    }
  }

  sealed interface Override<T> {
    fun Interceptor.Chain.value(): T

    fun Interceptor.Chain.withOverride(value: T): Interceptor.Chain

    fun OkHttpClient.Builder.withOverride(value: T): OkHttpClient.Builder

    val paramName: String?
      get() = null

    val nonDefaultValue: T

    val badValue: T

    fun isDefaultValue(value: T): Boolean