问题
I am using jsch to download files from server, my code 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 does download Text Document file types but fails for 'File' filetype
回答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 wanna use FILE and streams check this example:
http://kodehelp.com/java-program-for-downloading-file-from-sftp-server/
回答2:
Please find in the below code sample comprising the file upload and download functionalities. Please pull the relevant details from properties files where ever string marked in lt;sftp.user.namegt;. I am deleting the file once the file is downloaded you can have it as per your requirement.
The event and locale parameters what I have added as part of download functionality is to filter the file(s); you can pass parameters as par you need.
Have placed a check to set proxy which can be used on need basis.
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();
}
}
}
}
回答3:
I fixed in this way:
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
}
Where remotePath is the remote SFTP folder name.
来源：https://stackoverflow.com/questions/13680057/downloading-files-from-an-sftp-server-using-jsch