* </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 {

    public FtpClient ftpClient;

    @Override
    protected void setUp() throws Exception {
        super.setUp();
        StandardCrawlerContainer container = new StandardCrawlerContainer().singleton("mimeTypeHelper", MimeTypeHelperImpl.class)//
                .singleton("ftpClient", FtpClient.class);
        ftpClient = container.getComponent("ftpClient");
    }

		instance="prototype">
		<property name="charset">"UTF-8"</property>
		<!-- ntlmPasswordAuthentication -->
	</component>

	<component name="ftpClient"
		class="org.codelibs.fess.crawler.client.ftp.FtpClient" instance="prototype">
		<property name="charset">"UTF-8"</property>
	</component>

	<component name="storageClient"

import org.codelibs.fess.Constants;
import org.codelibs.fess.crawler.client.CrawlerClientFactory;
import org.codelibs.fess.crawler.client.ftp.FtpAuthentication;
import org.codelibs.fess.crawler.client.ftp.FtpClient;
import org.codelibs.fess.crawler.client.http.Authentication;
import org.codelibs.fess.crawler.client.http.HcHttpClient;
import org.codelibs.fess.crawler.client.http.form.FormScheme;

Pattern-based client selection using `LinkedHashMap<Pattern, CrawlerClient>`.

**Standard Patterns**:
```java
"^https?://.*"     → httpClient
"^file:.*"         → fileSystemClient
"^ftp://.*"        → ftpClient
"^smb://.*"        → smbClient
"^storage://.*"    → storageClient
```

### Services

**UrlQueueService**: URL queue management (FIFO), duplicate detection via `visited()`