Apache mina sshd :: sFTP implementation file upload and download method and download method and example
Apache Mina SSHD is a Java -based library for establishing a safe remote connection between SSH server and client.It allows us to upload and download files between server and clients with the SFTP protocol.
To implement file upload and download, we first need to set the SSH server and remote directory on the server side.The following is a simple example:
// Import the required class
import org.apache.sshd.server.SshServer;
import org.apache.sshd.sftp.server.SftpSubsystemFactory;
public class SftpServerExample {
public static void main(String[] args) throws Exception {
// Create an SSH server instance
SshServer sshd = SshServer.setUpDefaultServer();
// Set the host name and port of the server
sshd.setHost("localhost");
sshd.setPort(22);
// Set identity verification related information
sshd.setPasswordAuthenticator((username, password, session) -> "password".equals(password));
// Set the SFTP subsystem factory
SftpSubsystemFactory factory = new SftpSubsystemFactory.Builder().build();
sshd.setSubsystemFactories(Collections.singletonList(factory));
// Start the SSH server
sshd.start();
System.out.println("SFTP Server started...");
// Block the thread, keep the server running
Thread.sleep(Long.MAX_VALUE);
// Stop the SSH server
sshd.stop();
}
}
In the above code, we created an SSH server instance and performed some necessary configurations, such as host names, port number and password verification.We then set up a SFTP subsystem factory that will process the SFTP connection between the server and the client.
Next, we can use the SFTP protocol to connect to the server through the client to upload and download files.The following is an example of uploading and downloading files:
// Import the required class
import org.apache.sshd.client.SshClient;
import org.apache.sshd.client.channel.ChannelSftp;
import org.apache.sshd.client.session.ClientSession;
import org.apache.sshd.common.file.FileSystemFactory;
import org.apache.sshd.common.file.nativefs.NativeFileSystemFactory;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
public class SftpClientExample {
public static void main(String[] args) throws IOException {
// Create SSH client instance
SshClient client = SshClient.setUpDefaultClient();
// Set the host name and port of the client
client.setHost("localhost");
client.setPort(22);
// Set identity verification related information
client.setPasswordAuthenticator((username, password, session) -> "password".equals(password));
// Start the SSH client
client.start();
// Create the SFTP channel and connect
try (ClientSession session = client.connect("user", "localhost", 22).verify().getSession();
ChannelSftp channel = (ChannelSftp) session.createSftpChannel()) {
// Connect to the server
session.addPasswordIdentity("password");
session.auth().verify();
// upload files
Path localFile = Paths.get("local-file.txt");
String remoteDir = "/path/to/remote/directory/";
channel.put(localFile.toString(), remoteDir + localFile.getFileName());
// download file
String remoteFile = "/path/to/remote/file.txt";
Path destinationDir = Paths.get("destination-directory/");
channel.get(remoteFile, destinationDir.resolve(Paths.get(remoteFile).getFileName()).toString());
} finally {
// Close the SSH client
client.stop();
}
System.out.println("File uploaded and downloaded successfully using SFTP.");
}
}
In the above code, we have created an SSH client instance and performed the necessary configuration, such as host name, port number and password verification.We then connect to the server with the client and download and download the files through the SFTP channel.During the upload, we designate local files and remote directory, as well as the name of remote files.During the download process, we designate remote files and local directory.
In this way, we can use the Apache Mina SSHD library to implement the SFTP file upload and download function in Java.
Please note that the password verification of the server and the client in the above example is only used to demonstrate the purpose.Under actual situation, we should use more secure authentication methods, such as public key authentication.
I hope this article can help you understand how to use the Apache Mina SSHD library to achieve the function of uploading and downloading the SFTP file.
