关于java：如何通过SFTP从服务器检索文件？

How to retrieve a file from a server via SFTP?

我正在尝试使用Java使用SFTP(而不是FTPS)从服务器检索文件。我怎样才能做到这一点？

另一个选择是考虑查看JSch库。 JSch似乎是一些大型开源项目的首选库，包括Eclipse，Ant和Apache Commons HttpClient等。

它很好地支持用户/通过和基于证书的登录，以及所有其他美妙的SSH2功能。

这是一个通过SFTP检索的简单远程文件。错误处理留给读者练习:-)

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JSch jsch = new JSch();

String knownHostsFilename ="/home/username/.ssh/known_hosts";
jsch.setKnownHosts( knownHostsFilename );

Session session = jsch.getSession("remote-username","remote-host" );
{
//"interactive" version
// can selectively update specified known_hosts file
// need to implement UserInfo interface
// MyUserInfo is a swing implementation provided in
// examples/Sftp.java in the JSch dist
UserInfo ui = new MyUserInfo();
session.setUserInfo(ui);

// OR non-interactive version. Relies in host key being in known-hosts file
session.setPassword("remote-password" );
}

session.connect();

Channel channel = session.openChannel("sftp" );
channel.connect();

ChannelSftp sftpChannel = (ChannelSftp) channel;

sftpChannel.get("remote-file","local-file" );
// OR
InputStream in = sftpChannel.get("remote-file" );
// process inputstream as needed

sftpChannel.exit();
session.disconnect();

以下是使用JSch的示例的完整源代码，无需担心ssh密钥检查。

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import com.jcraft.jsch.*;

public class TestJSch {
public static void main(String args[]) {
JSch jsch = new JSch();
Session session = null;
try {
session = jsch.getSession("username","127.0.0.1", 22);
session.setConfig("StrictHostKeyChecking","no");
session.setPassword("password");
session.connect();

Channel channel = session.openChannel("sftp");
channel.connect();
ChannelSftp sftpChannel = (ChannelSftp) channel;
sftpChannel.get("remotefile.txt","localfile.txt");
sftpChannel.exit();
session.disconnect();
} catch (JSchException e) {
e.printStackTrace();
} catch (SftpException e) {
e.printStackTrace();
}
}
}

下面是使用Apache Common VFS的示例：

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FileSystemOptions fsOptions = new FileSystemOptions();
SftpFileSystemConfigBuilder.getInstance().setStrictHostKeyChecking(fsOptions,"no");
FileSystemManager fsManager = VFS.getManager();
String uri ="sftp://user:password@host:port/absolute-path";
FileObject fo = fsManager.resolveFile(uri, fsOptions);

在Jsch之上的一个很好的抽象是Apache commons-vfs，它提供了一个虚拟文件系统API，使得访问和编写SFTP文件几乎是透明的。为我们工作得很好。

这是我提出的解决方案
http://sourceforge.net/projects/sshtools/(为清晰起见，省略了大多数错误处理)。这是我博客的摘录

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SshClient ssh = new SshClient();
ssh.connect(host, port);
//Authenticate
PasswordAuthenticationClient passwordAuthenticationClient = new PasswordAuthenticationClient();
passwordAuthenticationClient.setUsername(userName);
passwordAuthenticationClient.setPassword(password);
int result = ssh.authenticate(passwordAuthenticationClient);
if(result != AuthenticationProtocolState.COMPLETE){
throw new SFTPException("Login to" + host +":" + port +"" + userName +"/" + password +" failed");
}
//Open the SFTP channel
SftpClient client = ssh.openSftpClient();
//Send the file
client.put(filePath);
//disconnect
client.quit();
ssh.disconnect();

对于SFTP，3个成熟的Java库有很好的比较：Commons VFS，SSHJ和JSch

总而言之，如果您不需要Commons VFS提供的其他存储支持，SSHJ具有最清晰的API，并且它是最好的。

这是来自github的编辑SSHJ示例：

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final SSHClient ssh = new SSHClient();
ssh.loadKnownHosts(); // or, to skip host verification: ssh.addHostKeyVerifier(new PromiscuousVerifier())
ssh.connect("localhost");
try {
ssh.authPassword("user","password"); // or ssh.authPublickey(System.getProperty("user.name"))
final SFTPClient sftp = ssh.newSFTPClient();
try {
sftp.get("test_file","/tmp/test.tmp");
} finally {
sftp.close();
}
} finally {
ssh.disconnect();
}

Apache Commons SFTP library

所有示例的公共java属性文件

serverAddress = 111.222.333.444

用户id = myUserId

密码= MYPASSWORD

remote目录=产品/

localDirectory =进口/

Upload file to remote server using SFTP

import java.io.File;
import java.io.FileInputStream;
import java.util.Properties;

import org.apache.commons.vfs2.FileObject;
import org.apache.commons.vfs2.FileSystemOptions;
import org.apache.commons.vfs2.Selectors;
import org.apache.commons.vfs2.impl.StandardFileSystemManager;
import org.apache.commons.vfs2.provider.sftp.SftpFileSystemConfigBuilder;

public class SendMyFiles {

static Properties props;

public static void main(String[] args) {

SendMyFiles sendMyFiles = new SendMyFiles();
if (args.length < 1)
{
System.err.println("Usage: java" + sendMyFiles.getClass().getName()+
" Properties_file File_To_FTP");
System.exit(1);
}

String propertiesFile = args[0].trim();
String fileToFTP = args[1].trim();
sendMyFiles.startFTP(propertiesFile, fileToFTP);

}

public boolean startFTP(String propertiesFilename, String fileToFTP){

props = new Properties();
StandardFileSystemManager manager = new StandardFileSystemManager();

try {

props.load(new FileInputStream("properties/" + propertiesFilename));
String serverAddress = props.getProperty("serverAddress").trim();
String userId = props.getProperty("userId").trim();
String password = props.getProperty("password").trim();
String remoteDirectory = props.getProperty("remoteDirectory").trim();
String localDirectory = props.getProperty("localDirectory").trim();

//check if the file exists
String filepath = localDirectory + fileToFTP;
File file = new File(filepath);
if (!file.exists())
throw new RuntimeException("Error. Local file not found");

//Initializes the file manager
manager.init();

//Setup our SFTP configuration
FileSystemOptions opts = new FileSystemOptions();
SftpFileSystemConfigBuilder.getInstance().setStrictHostKeyChecking(
opts,"no");
SftpFileSystemConfigBuilder.getInstance().setUserDirIsRoot(opts, true);
SftpFileSystemConfigBuilder.getInstance().setTimeout(opts, 10000);

//Create the SFTP URI using the host name, userid, password, remote path and file name
String sftpUri ="sftp://" + userId +":" + password + "@" + serverAddress +"/" +
remoteDirectory + fileToFTP;

// Create local file object
FileObject localFile = manager.resolveFile(file.getAbsolutePath());

// Create remote file object
FileObject remoteFile = manager.resolveFile(sftpUri, opts);

// Copy local file to sftp server
remoteFile.copyFrom(localFile, Selectors.SELECT_SELF);
System.out.println("File upload successful");

}
catch (Exception ex) {
ex.printStackTrace();
return false;
}
finally {
manager.close();
}

return true;
}

}

Download file from remote server using SFTP

import java.io.File;
import java.io.FileInputStream;
import java.util.Properties;

import org.apache.commons.vfs2.FileObject;
import org.apache.commons.vfs2.FileSystemOptions;
import org.apache.commons.vfs2.Selectors;
import org.apache.commons.vfs2.impl.StandardFileSystemManager;
import org.apache.commons.vfs2.provider.sftp.SftpFileSystemConfigBuilder;

public class GetMyFiles {

static Properties props;

public static void main(String[] args) {

GetMyFiles getMyFiles = new GetMyFiles();
if (args.length < 1)
{
System.err.println("Usage: java" + getMyFiles.getClass().getName()+
" Properties_filename File_To_Download");
System.exit(1);
}

String propertiesFilename = args[0].trim();
String fileToDownload = args[1].trim();
getMyFiles.startFTP(propertiesFilename, fileToDownload);

}

public boolean startFTP(String propertiesFilename, String fileToDownload){

props = new Properties();
StandardFileSystemManager manager = new StandardFileSystemManager();

try {

props.load(new FileInputStream("properties/" + propertiesFilename));
String serverAddress = props.getProperty("serverAddress").trim();
String userId = props.getProperty("userId").trim();
String password = props.getProperty("password").trim();
String remoteDirectory = props.getProperty("remoteDirectory").trim();
String localDirectory = props.getProperty("localDirectory").trim();

//Initializes the file manager
manager.init();

//Setup our SFTP configuration
FileSystemOptions opts = new FileSystemOptions();
SftpFileSystemConfigBuilder.getInstance().setStrictHostKeyChecking(
opts,"no");
SftpFileSystemConfigBuilder.getInstance().setUserDirIsRoot(opts, true);
SftpFileSystemConfigBuilder.getInstance().setTimeout(opts, 10000);

//Create the SFTP URI using the host name, userid, password, remote path and file name
String sftpUri ="sftp://" + userId +":" + password + "@" + serverAddress +"/" +
remoteDirectory + fileToDownload;

// Create local file object
String filepath = localDirectory + fileToDownload;
File file = new File(filepath);
FileObject localFile = manager.resolveFile(file.getAbsolutePath());

// Create remote file object
FileObject remoteFile = manager.resolveFile(sftpUri, opts);

// Copy local file to sftp server
localFile.copyFrom(remoteFile, Selectors.SELECT_SELF);
System.out.println("File download successful");

}
catch (Exception ex) {
ex.printStackTrace();
return false;
}
finally {
manager.close();
}

return true;
}

}

Delete a file on remote server using SFTP

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import java.io.FileInputStream;
import java.util.Properties;

import org.apache.commons.vfs2.FileObject;
import org.apache.commons.vfs2.FileSystemOptions;
import org.apache.commons.vfs2.impl.StandardFileSystemManager;
import org.apache.commons.vfs2.provider.sftp.SftpFileSystemConfigBuilder;

public class DeleteRemoteFile {

static Properties props;

public static void main(String[] args) {

DeleteRemoteFile getMyFiles = new DeleteRemoteFile();
if (args.length < 1)
{
System.err.println("Usage: java" + getMyFiles.getClass().getName()+
" Properties_filename File_To_Delete");
System.exit(1);
}

String propertiesFilename = args[0].trim();
String fileToDownload = args[1].trim();
getMyFiles.startFTP(propertiesFilename, fileToDownload);

}

public boolean startFTP(String propertiesFilename, String fileToDownload){

props = new Properties();
StandardFileSystemManager manager = new StandardFileSystemManager();

try {

props.load(new FileInputStream("properties/" + propertiesFilename));
String serverAddress = props.getProperty("serverAddress").trim();
String userId = props.getProperty("userId").trim();
String password = props.getProperty("password").trim();
String remoteDirectory = props.getProperty("remoteDirectory").trim();

//Initializes the file manager
manager.init();

//Setup our SFTP configuration
FileSystemOptions opts = new FileSystemOptions();
SftpFileSystemConfigBuilder.getInstance().setStrictHostKeyChecking(
opts,"no");
SftpFileSystemConfigBuilder.getInstance().setUserDirIsRoot(opts, true);
SftpFileSystemConfigBuilder.getInstance().setTimeout(opts, 10000);

//Create the SFTP URI using the host name, userid, password, remote path and file name
String sftpUri ="sftp://" + userId +":" + password + "@" + serverAddress +"/" +
remoteDirectory + fileToDownload;

//Create remote file object
FileObject remoteFile = manager.resolveFile(sftpUri, opts);

//Check if the file exists
if(remoteFile.exists()){
remoteFile.delete();
System.out.println("File delete successful");
}

}
catch (Exception ex) {
ex.printStackTrace();
return false;
}
finally {
manager.close();
}

return true;
}

}

hierynomus / sshj完整实现了SFTP版本3(OpenSSH实现的)

SFTPUpload.java中的示例代码

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package net.schmizz.sshj.examples;

import net.schmizz.sshj.SSHClient;
import net.schmizz.sshj.sftp.SFTPClient;
import net.schmizz.sshj.xfer.FileSystemFile;

import java.io.File;
import java.io.IOException;

/** This example demonstrates uploading of a file over SFTP to the SSH server. */
public class SFTPUpload {

public static void main(String[] args)
throws IOException {
final SSHClient ssh = new SSHClient();
ssh.loadKnownHosts();
ssh.connect("localhost");
try {
ssh.authPublickey(System.getProperty("user.name"));
final String src = System.getProperty("user.home") + File.separator +"test_file";
final SFTPClient sftp = ssh.newSFTPClient();
try {
sftp.put(new FileSystemFile(src),"/tmp");
} finally {
sftp.close();
}
} finally {
ssh.disconnect();
}
}

}

JSch库是功能强大的库，可用于从SFTP服务器读取文件。下面是逐行读取SFTP位置文件的测试代码

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JSch jsch = new JSch();
Session session = null;
try {
session = jsch.getSession("user","127.0.0.1", 22);
session.setConfig("StrictHostKeyChecking","no");
session.setPassword("password");
session.connect();

Channel channel = session.openChannel("sftp");
channel.connect();
ChannelSftp sftpChannel = (ChannelSftp) channel;

InputStream stream = sftpChannel.get("/usr/home/testfile.txt");
try {
BufferedReader br = new BufferedReader(new InputStreamReader(stream));
String line;
while ((line = br.readLine()) != null) {
System.out.println(line);
}

} catch (IOException io) {
System.out.println("Exception occurred during reading file from SFTP server due to" + io.getMessage());
io.getMessage();

} catch (Exception e) {
System.out.println("Exception occurred during reading file from SFTP server due to" + e.getMessage());
e.getMessage();

}

sftpChannel.exit();
session.disconnect();
} catch (JSchException e) {
e.printStackTrace();
} catch (SftpException e) {
e.printStackTrace();
}

请参考博客了解整个计划。

Andy，要删除远程系统上的文件，你需要使用(channelExec)的JSch并传递unix / linux命令来删除它。

我使用JSCH API在java中找到了SFTP的完整工作示例
http://kodehelp.com/java-program-for-uploading-file-to-sftp-server/

试试edtFTPj / PRO，这是一个成熟，强大的SFTP客户端库，支持连接池和异步操作。还支持FTP和FTPS，因此涵盖了安全文件传输的所有基础。

虽然上面的答案非常有用，但我花了一天的时间让它们工作，面对各种例外，例如"破碎通道"，"rsa密钥未知"和"数据包损坏"。

下面是使用JSch库的SFTP FILES UPLOAD / DOWNLOAD的可重用类。

上传用法：

1	SFTPFileCopy upload = new SFTPFileCopy(true, /path/to/sourcefile.png", /path/to/destinationfile.webp");

下载用法：

1	SFTPFileCopy download = new SFTPFileCopy(false,"/path/to/sourcefile.webp","/path/to/destinationfile.webp");

类代码：

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import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelSftp;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.Session;
import com.jcraft.jsch.UIKeyboardInteractive;
import com.jcraft.jsch.UserInfo;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import javax.swing.JOptionPane;
import menue.Menue;

public class SFTPFileCopy1 {

public SFTPFileCopy1(boolean upload, String sourcePath, String destPath) throws FileNotFoundException, IOException {
Session session = null;
Channel channel = null;
ChannelSftp sftpChannel = null;
try {
JSch jsch = new JSch();
//jsch.setKnownHosts("/home/user/.putty/sshhostkeys");
session = jsch.getSession("login","mysite.com", 22);
session.setPassword("password");

UserInfo ui = new MyUserInfo() {
public void showMessage(String message) {

JOptionPane.showMessageDialog(null, message);

}

public boolean promptYesNo(String message) {

Object[] options = {"yes","no"};

int foo = JOptionPane.showOptionDialog(null,
message,
"Warning",
JOptionPane.DEFAULT_OPTION,
JOptionPane.WARNING_MESSAGE,
null, options, options[0]);

return foo == 0;

}
};
session.setUserInfo(ui);

session.setConfig("StrictHostKeyChecking","no");
session.connect();
channel = session.openChannel("sftp");
channel.setInputStream(System.in);
channel.setOutputStream(System.out);
channel.connect();
sftpChannel = (ChannelSftp) channel;

if (upload) { // File upload.
byte[] bufr = new byte[(int) new File(sourcePath).length()];
FileInputStream fis = new FileInputStream(new File(sourcePath));
fis.read(bufr);
ByteArrayInputStream fileStream = new ByteArrayInputStream(bufr);
sftpChannel.put(fileStream, destPath);
fileStream.close();
} else { // File download.
byte[] buffer = new byte[1024];
BufferedInputStream bis = new BufferedInputStream(sftpChannel.get(sourcePath));
OutputStream os = new FileOutputStream(new File(destPath));
BufferedOutputStream bos = new BufferedOutputStream(os);
int readCount;
while ((readCount = bis.read(buffer)) > 0) {
bos.write(buffer, 0, readCount);
}
bis.close();
bos.close();
}
} catch (Exception e) {
System.out.println(e);
} finally {
if (sftpChannel != null) {
sftpChannel.exit();
}
if (channel != null) {
channel.disconnect();
}
if (session != null) {
session.disconnect();
}
}
}

public static abstract class MyUserInfo
implements UserInfo, UIKeyboardInteractive {

public String getPassword() {
return null;
}

public boolean promptYesNo(String str) {
return false;
}

public String getPassphrase() {
return null;
}

public boolean promptPassphrase(String message) {
return false;
}

public boolean promptPassword(String message) {
return false;
}

public void showMessage(String message) {
}

public String[] promptKeyboardInteractive(String destination,
String name,
String instruction,
String[] prompt,
boolean[] echo) {

return null;
}
}
}

你也有JFileUpload和SFTP附加组件(Java也是)：
http://www.jfileupload.com/products/sftp/index.html

我使用这个名为Zehon的SFTP API，它很棒，很容易使用大量的示例代码。这是网站http://www.zehon.com

我发现的最佳解决方案是Paramiko。有一个Java版本。