downloading all files from sftp server in java

I am trying to Download All files from folder on SFTP server , Below is my Code Please suggest changes so i can download All available files from remote directory and can save to Local Directory

package svb.ftp.bs.load;
import com.jcraft.jsch.JSchException;
import com.jcraft.jsch.SftpException;
import java.io.FileNotFoundException;
import java.io.File;
import java.io.FileInputStream;
import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelSftp;
import com.jcraft.jsch.JSch;
import java.io.InputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.List;
import org.apache.commons.net.ftp.FTP;
import org.apache.commons.io.IOUtils;
import org.junit.Test;
import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelExec;
import com.jcraft.jsch.ChannelSftp;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.JSchException;
import com.jcraft.jsch.Session;
import com.jcraft.jsch.SftpException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Vector;
public class downloadFtp {
public static void main(String[] args) {
String SFTPHOST = "host";
int SFTPPORT = 22;
String SFTPUSER = "user";
String SFTPPASS = "Pass";
String privateKey = "E:\\Oracle\\mywork\\DownloadFTP\\ppk.ppk";
String SFTPWORKINGDIR = "Inbox/ARR_SI_MedicalTranscriptionBillCorp_PD_20200724_32137.TXT";
com.jcraft.jsch.Session session = null;
Channel channel = null;
ChannelSftp channelSftp = null;
JSch jsch = new JSch();
try {
jsch.addIdentity(privateKey);
session = jsch.getSession(SFTPUSER, SFTPHOST, SFTPPORT);
session.setPassword(SFTPPASS);
java.util.Properties config = new java.util.Properties();
config.put("StrictHostKeyChecking", "no");
session.setConfig(config);
session.connect();
channel = session.openChannel("sftp");
channel.connect();
System.out.println("Connected");
channelSftp = (ChannelSftp) channel;
channelSftp.cd(SFTPWORKINGDIR);
InputStream is = channelSftp.get(SFTPWORKINGDIR);
IOUtils.copy(is, System.out);
is.close();
System.out.println("File Uploaded to FTP Server Sucessfully.");
} catch (JSchException jse) {
// TODO: Add catch code
jse.printStackTrace();
} catch (SftpException se) {
// TODO: Add catch code
se.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
}

Currently when i run the code it show below error

4: Can't change directory: /Inbox/ARR_SI_MedicalTranscriptionBillCorp_PD_20200724_32137.TXT
at com.jcraft.jsch.ChannelSftp.cd(ChannelSftp.java:350)
at svb.ftp.bs.load.downloadFtp.main(downloadFtp.java:67)
Process exited with exit code 0.

The stacktrace is telling you what's wrong.

> Can't change directory: /Inbox/ARR_SI_MedicalTranscriptionBillCorp_PD_20200724_32137.TXT

Problem is with:

channelSftp.cd(SFTPWORKINGDIR);

Here you are passing filename but its expecting a directory (cd stands for Change Directory). You cannot do CD to a file.

If you pass a folder/path it would work. Try the following :

channelSftp.cd("/Inbox/a_folder/");

How to Download All:
Reference: https://ganeshtiwaridotcomdotnp.blogspot.com/2020/07/download-files-from-ftp-using-jsch-java.html

In order to download all files, first list all files in root folder, iterate over it.. if its a file download, if its a folder list the content and keep doing it recursively for sub folders.

The following is an example of how to download files from a defined folder:

import com.jcraft.jsch.*;
import java.util.Properties;
import java.util.Vector;
public class JschDownload {
public static void main(String[] args) {
Session session = null;
Channel channel = null;
JSch jsch = new JSch();
try {
session = jsch.getSession("demo", "test.rebex.net", 22);
session.setPassword("password");
Properties config = new Properties();
config.put("StrictHostKeyChecking", "no");
session.setConfig(config);
session.connect();
System.out.println("session connect");
channel = session.openChannel("sftp");
channel.connect();
System.out.println("Connected");
ChannelSftp channelSftp = (ChannelSftp) channel;
downloadFromFolder(channelSftp, "/");
downloadFromFolder(channelSftp, "/pub/example/");
System.out.println("File Uploaded to FTP Server Sucessfully.");
} catch (Exception e) {
e.printStackTrace();
} finally {
if (channel != null) {
channel.disconnect();
}
session.disconnect();
}
}
static void downloadFromFolder(ChannelSftp channelSftp, String folder) throws SftpException {
Vector<ChannelSftp.LsEntry> entries = channelSftp.ls(folder);
System.out.println(entries);
//download all from root folder
for (ChannelSftp.LsEntry en : entries) {
if (en.getFilename().equals(".") || en.getFilename().equals("..") || en.getAttrs().isDir()) {
continue;
}
System.out.println(en.getFilename());
channelSftp.get(folder + en.getFilename(), en.getFilename());
}
}
}

Refer to http://www.jcraft.com/jsch/examples/ for examples and documentation of the jsch library.

here a recursive methode to get all files in sub folder also

private void downloadFromFolder( String remotePath, String localPath ) throws SftpException {
try
{
Vector<ChannelSftp.LsEntry> entries = channel.ls(remotePath);
System.out.println(entries);
//download all from root folder
for (ChannelSftp.LsEntry en : entries) {
if(!en.getFilename().equals(".") && !en.getFilename().equals("..") && en.getAttrs().isDir())
{
Path path = Paths.get(localPath + "\\" + en.getFilename());
Files.createDirectories(path);
downloadFromFolder(remotePath + "/" + en.getFilename(),path.toString());
continue;
}
if (en.getFilename().equals(".") || en.getFilename().equals("..")) {
continue;
}
System.out.println(en.getFilename());
channel.get(remotePath + "/" + en.getFilename(), localPath + "\\" + en.getFilename());
}
}catch(Exception e)
{
}
}