Download files from an SFTP server using JSch

Question

I use jsch to download files from the server, my code is below.

public static void downloadFile(TpcCredentialsDTO dto) { logger.trace("Entering downloadFile() method"); Session session = null; Channel channel = null; ChannelSftp channelSftp = null; boolean success = false; try { JSch jsch = new JSch(); session = jsch.getSession(dto.getUsername(), dto.getHost(), dto.getPort()); session.setPassword(dto.getPassword()); session.setConfig("StrictHostKeyChecking", "no"); session.connect(); logger.info("Connected to " + dto.getHost() + "."); channel = session.openChannel("sftp"); channel.connect(); channelSftp = (ChannelSftp) channel; List<String> filesToDownload = getFilesToDownload(dto,channelSftp); if (!filesToDownload.isEmpty()) { for (String fileDownloadName : filesToDownload) { success = false; OutputStream output = new FileOutputStream( "C:\Download\BLT_03112012"); channelSftp.get("BLT_03112012",output); success = true; if (success) logger.info(ServerConstants.DOWNLOAD_SUCCESS_MSG + fileDownloadName); output.close(); } }else { logger.info(ServerConstants.NO_FILES_TO_DOWNLOAD + ServerUtils.getDateTime()); success = true; } } catch (JSchException ex) { logger.error( ServerConstants.SFTP_REFUSED_CONNECTION, ex); } catch (SftpException ex) { logger.error(ServerConstants.FILE_DOWNLOAD_FAILED, ex); } catch (IOException ex) { logger.error(ServerConstants.FILE_NOT_FOUND, ex); }catch (Exception ex) { logger.error(ServerConstants.ERROR, ex); }finally { if (channelSftp.isConnected()) { try { session.disconnect(); channel.disconnect(); channelSftp.quit(); logger.info( ServerConstants.FTP_DISCONNECT); } catch (Exception ioe) { logger.error(ServerConstants.FTP_NOT_DISCONNECT, ioe); } } } logger.trace("Exiting downloadFile() method"); } sftpChannel.get(filename, outputstream) is throwing an error. 

  2: File not found at com.jcraft.jsch.ChannelSftp.throwStatusError(ChannelSftp.java:2629) at com.jcraft.jsch.ChannelSftp._get(ChannelSftp.java:977) at com.jcraft.jsch.ChannelSftp.get(ChannelSftp.java:946) at com.jcraft.jsch.ChannelSftp.get(ChannelSftp.java:924) at za.co.tpc.sftpserver.SftpConnection.downloadFile(SftpConnection.java:72) at za.co.tpc.server.execute.FtpMtn.main(FtpMtn.java:44) 

The same code loads the file types of a text document, but does not work for a File Type file

Answer 1

Try using paths instead of stream:

  String destPath = "filename.txt"; if (!filesToDownload.isEmpty()) { for (String fileDownloadName : filesToDownload) { success = false; sftpChannel.get(fileDownloadName , destPath); 

EDIT if you want to use FILE and streams check this example:

http://kodehelp.com/java-program-for-downloading-file-from-sftp-server/

Answer 2

The following code example contains upload and download files. Please pull the relevant data from the properties files, wherever the line marked in lt is; sftp.user.name gt; . I delete the file after downloading the file, which you can get as per your requirement.

The event and locale parameters that I added as part of the download function are file filtering; You can pass parameters according to your parameters.

We placed a check to install a proxy server, which can be used as needed.

 package com.util; import com.jcraft.jsch.Channel; import com.jcraft.jsch.ChannelSftp; import com.jcraft.jsch.JSch; import com.jcraft.jsch.ProxyHTTP; import com.jcraft.jsch.Session; import com.jcraft.jsch.SftpException; import java.io.File; import java.io.FileInputStream; import java.util.Date; import java.util.Properties; import java.util.Vector; /** * * @author Dinesh.Lomte */ public class SftpUtil { /** * * @param fileName * @throws Exception */ public static void upload(String fileName) throws Exception { String method = "upload(String fileName)"; Session session = null; Channel channel = null; ChannelSftp channelSftp = null; try { // Creating and instantiating the jsch specific instance JSch jsch = new JSch(); // Fetching and setting the parameters like: user name, host and port // from the properties file session = jsch.getSession("<sftp.user.name>", "<sftp.host>", Integer.valueOf("<sftp.port>")); // Fetching and setting the password as configured in properties files session.setPassword("<sftp.user.password>"); // Setting the configuration specific properties Properties config = new Properties(); config.put("StrictHostKeyChecking", "no"); session.setConfig(config); // Validating if proxy is enabled to access the sftp isSftpProxyEnabled(session); // Execution start time long lStartTime = new Date().getTime(); System.out.println("Connecting to the sftp..."); // Connecting to the sftp session.connect(); System.out.println("Connected to the sftp."); // Execution end time long lEndTime = new Date().getTime(); System.out.println("---------------------------------------------"); System.out.println("Connected to SFTP in : " + (lEndTime - lStartTime)); // Setting the channel type as sftp channel = session.openChannel("sftp"); // Establishing the connection channel.connect(); channelSftp = (ChannelSftp) channel; // Setting the folder location of the external system as configured channelSftp.cd("<sftp.output.folder.url>"); // Creating the file instance File file = new File(fileName); // Creating an fileInputStream instance FileInputStream fileInputStream = new FileInputStream(file); // Transfering the file from it source to destination location via sftp channelSftp.put(fileInputStream, file.getName()); // Closing the fileInputStream instance fileInputStream.close(); // De-allocating the fileInputStream instance memory by assigning null fileInputStream = null; } catch (Exception exception) { throw exception; } finally { // Validating if channel sftp is not null to exit if (channelSftp != null) { channelSftp.exit(); } // Validating if channel is not null to disconnect if (channel != null) { channel.disconnect(); } // Validating if session instance is not null to disconnect if (session != null) { session.disconnect(); } } } /** * * @param session */ private static void isSftpProxyEnabled(Session session) { // Fetching the sftp proxy flag set as part of the properties file boolean isSftpProxyEnabled = Boolean.valueOf("<sftp.proxy.enable>"); // Validating if proxy is enabled to access the sftp if (isSftpProxyEnabled) { // Setting host and port of the proxy to access the SFTP session.setProxy(new ProxyHTTP("<sftp.proxy.host>", Integer.valueOf("<sftp.proxy.port>"); } System.out.println("Proxy status: " + isSftpProxyEnabled); } /** * * @param folder * @param event * @param locale */ public static void download(String folder, String event, String locale) { String method = "download(String folder, String event, String locale)"; Session session = null; Channel channel = null; ChannelSftp channelSftp = null; try { // Creating and instantiating the jsch specific instance JSch jsch = new JSch(); // Fetching and setting the parameters like: user name, host and port // from the properties file session = jsch.getSession("<sftp.user.name>", "<sftp.host>", Integer.valueOf("<sftp.port>")); // Fetching and setting the password as configured in properties files session.setPassword("<sftp.user.password>"); // Setting the configuration specific properties Properties config = new Properties(); config.put("StrictHostKeyChecking", "no"); session.setConfig(config); // Validating if proxy is enabled to access the sftp isSftpProxyEnabled(session); // Execution start time long lStartTime = new Date().getTime(); System.out.println("Connecting to the sftp..."); // Connecting to the sftp session.connect(); System.out.println("Connected to the sftp."); // Execution end time long lEndTime = new Date().getTime(); System.out.println("---------------------------------------------"); System.out.println("Connected to SFTP in : " + (lEndTime - lStartTime)); // Setting the channel type as sftp channel = session.openChannel(SFTP); // Establishing the connection channel.connect(); channelSftp = (ChannelSftp) channel; try { // Setting the folder location of the external system as configured // to download the file from channelSftp.cd("<sftp.input.folder.url>"); } catch (SftpException sftpException) { System.out.println("Failed to change the directory in sftp."); } // Listing all the .csv file(s) specific to the source system, event type (download) and locale code Vector<ChannelSftp.LsEntry> lsEntries = channelSftp.ls( new StringBuilder("*").append("<sys.code>").append("*").append(event) .append("*").append(locale).append("*").append(".csv").toString()); // Validating if files exist to process the request further if (lsEntries.isEmpty()) { System.out.println("No file exist in the specified sftp folder location."); } // Iterating the list of entries to download the file(s) from the sftp for (ChannelSftp.LsEntry entry : lsEntries) { try { // Downloading the specified file from the sftp to the specified folder path channelSftp.get(entry.getFilename(), new StringBuilder(folder) .append(File.separator).append(entry.getFilename()).toString()); } catch (SftpException sftpException) { System.out.println("Failed to download the file the sftp folder location."); } } // Iterating the list of entries to delete the file(s) from the sftp for (ChannelSftp.LsEntry entry : lsEntries) { try { // Deleting the specified file from the sftp channelSftp.rm(entry.getFilename()); } catch (SftpException sftpException) { System.out.println("Failed to delete the file from the sftp folder location."); } } } catch (Exception exception) { System.out.println("Failed to download the file(s) from SFTP."); } finally { // Validating if channel sftp is not null to exit if (channelSftp != null) { channelSftp.exit(); } // Validating if channel is not null to disconnect if (channel != null) { channel.disconnect(); } // Validating if session instance is not null to disconnect if (session != null) { session.disconnect(); } } } } 

Answer 3

I fixed as follows:

 Vector<ChannelSftp.LsEntry> files = sftp.ls(remotePath); String remotePath = properties.getFtpPath(); Vector<ChannelSftp.LsEntry> files = sftp.ls(remotePath); for (ChannelSftp.LsEntry entry : files) { InputStream stream = sftp.get(remotePath + "/" + entry.getFilename()); // Your business code here } 

If remotePath is the remote SFTP folder name.