How to configure spring integration adapters to get and put a file via SFTP

I'm trying to implement the following scenario using Spring Integration:

The input channel should poll a SFTP site to get a file storing it in a local "stfp-inbound" folder.
The output channel should push an existing file in a local "sftp-outbound" folder to the SFTP site.
I started with the input channel. It had worked so far but it is obviously very static.

This is my config so far:

@Component
public class SftpClient {
    private static final Logger LOG = LoggerFactory.getLogger(SftpClient.class);

@Bean
public IntegrationFlow sftpInboundFlow() {
    return IntegrationFlows
        .from(Sftp.inboundAdapter(sftpSessionFactory())
                .preserveTimestamp(true)
                .remoteDirectory("data")
                .regexFilter(".*\\.txt$")
//                    .localFilenameExpression("#this.toUpperCase() + '.a'")
                .localDirectory(new File("ftp-inbound")),
             e -> e.id("sftpInboundAdapter")
                .autoStartup(true)
                .poller(Pollers.fixedDelay(5000)))
        .handle(m -> System.out.println(m.getPayload()))
        .get();
}

@Bean
public IntegrationFlow sftpOutboundFlow() {
    return IntegrationFlows.from("toSftpChannel")
        .handle(Sftp.outboundAdapter(sftpSessionFactory(), FileExistsMode.FAIL)
                     .useTemporaryFileName(false)
                     .remoteDirectory("/data")
        ).get();
}

@Bean
public SessionFactory<LsEntry> sftpSessionFactory() {
//		// with private key resource: catch MalformedURLException
//		try {
		DefaultSftpSessionFactory factory = new DefaultSftpSessionFactory(true);
		factory.setHost("myHost");
		factory.setPort(22);
		factory.setUser("myUser");
		factory.setPassword("myPassword");
//			factory.setPrivateKey(new FileUrlResource("/Users/myUser/.ssh/id_rsa"));
//			factory.setPrivateKeyPassphrase("passphrase");
		factory.setAllowUnknownKeys(true);
		return new CachingSessionFactory<LsEntry>(factory);
//		}
//		catch (MalformedURLException e) {
//			throw new IllegalArgumentException("malformed URL");
//		}
}

I need advice to make a more dynamic approach.
I imagin a component class with public methods sftpGet() and sftpPut() to get and put a file, whereas the channels are created by integration flows with the required parameters that made up a SFTP transfer: hostname, port, user, password, remote dir, local dir.

How can I achieve that?

I got a good hint with a similar TCP/IP channel scenario but I couldn't transform those solution to this SFTP scenario.

Please advice!

After taking in Gary's recommendations I did the foolowing dynamic Bean:

@Component
public class DynamicSftpTemplate implements InputStreamCallback {
	private static Logger LOG = LoggerFactory.getLogger(DynamicSftpTemplate.class);

	private String localDir;
	private String localFilename;

	public void getSftpFile(String sessionId, String host, int port, String user, String password,
			String remoteDir, String remoteFilename, String localDir, String localFilename) {
		LOG.debug("getSftpFile sessionId={}", sessionId);
		ioSftpFile(GET, host, port, user, password,
				remoteDir, remoteFilename, localDir, localFilename);
	}

	public void putSftpFile(String sessionId, String host, int port, String user, String password,
			String remoteDir, String remoteFilename, String localDir, String localFilename) {
		LOG.debug("putSftpFile sessionId={}", sessionId);
		ioSftpFile(PUT, host, port, user, password,
				remoteDir, remoteFilename, localDir, localFilename);
	}

	public void rmSftpFile(String sessionId, String host, int port, String user, String password,
			String remoteDir, String remoteFilename) {
		LOG.debug("rmSftpFile sessionId={}", sessionId);
		ioSftpFile(RM, host, port, user, password, remoteDir, remoteFilename, null, null);
	}

	private void ioSftpFile(SftpOperationType op, String host, int port, String user, String password,
			String remoteDir, String remoteFilename, String localDir, String localFilename) {
		LOG.debug("ioSftpFile op={}, host={}, port={}", op, host, port);
		LOG.debug("ioSftpFile user={}, password={}", user, password);
		SftpRemoteFileTemplate template = new SftpRemoteFileTemplate(sftpSessionFactory(host, port, user, password));
		template.setFileNameExpression(new LiteralExpression(remoteDir + "/" + remoteFilename));
		template.setRemoteDirectoryExpression(new LiteralExpression(remoteDir));

		//template.afterPropertiesSet();
		this.localDir = localDir;
		this.localFilename = localFilename;
		if (op == GET) {
			// template.get(buildGetMessage(remoteDir, remoteFilename), (InputStreamCallback) this);
			template.get(remoteDir + "/" + remoteFilename, this);
		}
		else if (op == PUT) {
			template.send(buildPutMessage(remoteDir, remoteFilename), FileExistsMode.REPLACE);			
		}
		else if (op == RM) {
			template.remove(remoteDir + "/" + remoteFilename);			
		}
		else {
			throw new IllegalArgumentException("invalid sftp operation, " + op);
		}
	}

	private DefaultSftpSessionFactory sftpSessionFactory(String host, int port, String user, String password) {
		LOG.debug("sftpSessionFactory");
		DefaultSftpSessionFactory factory = new DefaultSftpSessionFactory(true);
		factory.setHost(host);
		factory.setPort(port);
		factory.setUser(user);
		factory.setPassword(password);
		factory.setAllowUnknownKeys(true);
		return factory;
	}

	private Message<?> buildPutMessage(String remoteDir, String remoteFilename) {
		return MessageBuilder.withPayload(new File(this.localDir + "/" + this.localFilename))
				.setHeader("file_remoteDirectory", remoteDir)
				.setHeader("file_remoteFile", remoteFilename)
				.build();
	}

	public void doWithInputStream(InputStream is) throws IOException {
		LOG.debug("doWithInputStream");
		String fullPathName = this.localDir + "/" + this.localFilename;
		FileWriter w = new FileWriter(fullPathName);
		IOUtils.copy(is, w, "UTF-8");
		LOG.debug("doWithInputStream file {} written", fullPathName);
		w.close();
		is.close();
	}
}

You can use SFTP Gateways to get and put files (amongst other operations).

Or, you can just use an SftpRemoteFileTemplate directly.