SFTP monitoring with JSCH

CustomSftpProgressMonitor.java

import com.jcraft.jsch.SftpProgressMonitor;
import lombok.Getter;
import lombok.RequiredArgsConstructor;
import lombok.Setter;

@RequiredArgsConstructor
public class CustomSftpProgressMonitor implements SftpProgressMonitor {

    private final long totalbytes;

    private long uploadedBytes = 0;

    private double previousPercentage = 0;

    @Getter @Setter
    private ProgressListener progressListener;

    @Override
    public void init(int op, String src, String dest, long max) {
        System.out.println("Start uploading...");
    }

    @Override
    public boolean count(long bytes) {
        uploadedBytes +=bytes;

        double currentPercentage = calculatePercentage(uploadedBytes, totalbytes);

        if(currentPercentage != previousPercentage){
            previousPercentage = currentPercentage;
            if(progressListener != null){
                progressListener.change(currentPercentage);
            }
        }

        return true;
    }

    @Override
    public void end() {
        System.out.println("Success uploaded...");
    }

    private double calculatePercentage(double obtained, double total) {
        return Math.round(obtained * 100 / total);
    }
}

Main.java

public static void main(String[] args) throws IOException, JSchException {

        Session session = connect("some_ip", 22, "username", "password");
  
          if(session.isConnected()){
            // SFTP
            ChannelSftp channelSftp = null;

            try {

                File file = new File("someFolder/someFile");
                if(file.exists()){

                    // SFTP
                    channelSftp = (ChannelSftp) session.openChannel("sftp");
                    channelSftp.connect();

                    // transfer to specific directory
                    try{
                        channelSftp.mkdir("temp");
                    } catch (SftpException e){
                        //If cannot make directory, means directory already created
                    }
                    channelSftp.cd("temp");

                    // Monitoring
                    CustomSftpProgressMonitor monitor = new CustomSftpProgressMonitor(file.length());
                    monitor.setProgressListener(currentPercentage -> System.out.println("Percentage: " + currentPercentage + " %"));

                    // Send
                    channelSftp.put(new FileInputStream(file), file.getName(), monitor);
                }

            } catch (SftpException e) {
                e.printStackTrace();
            } finally {
                if(channelSftp != null){
                    channelSftp.exit();
                }
                
                session.disconnect();
            }
        }
}

public static Session connect(String host, Integer port, String user, String password) throws JSchException {
        Session session = null;
        try {
            JSch jsch = new JSch();
            if(port != null){
                session = jsch.getSession(user, host, port.intValue());
            }else{
                session = jsch.getSession(user, host);
            }
            session.setPassword(password);

            session.setConfig("StrictHostKeyChecking", "no");
            //time out
            session.connect(3000);
        } catch (JSchException e) {
            e.printStackTrace();
            System.out.println("SFTPUitl connection error");
            throw e;
        }
        return session;
    }

ProgressListener.java

public interface ProgressListener {
    void change(double currentPercentage);
}