java - 使用 Java 通过 SFTP 下载多个文件

Question

我是 Java 新手，我正在尝试编写一个脚本，该脚本将每天从各种 SFTP 站点提取多个文件。

我下面的代码将从 1 个站点中提取 1 个文件并且它可以工作，但是我正在努力寻找如何修改我的代码以便它可以下载多个文件。因此，例如远程目录中的所有文件，或仅包含某些字母的某些文件

你能给我建议吗？

代码：-

package package1;  

import java.io.BufferedInputStream;  
import java.io.BufferedOutputStream;  
import java.io.File;  
import java.io.FileOutputStream;  
import java.io.OutputStream;  
import com.jcraft.jsch.Channel;  
import com.jcraft.jsch.ChannelSftp;  
import com.jcraft.jsch.JSch;  
import com.jcraft.jsch.Session;  



public class SFTPpullsshkeys {  
public SFTPpullsshkeys() {  
                          }

public static void main(String[] args) {  
        String SFTPHOST = "IP";  
        int    SFTPPORT = 22;  
        String SFTPUSER = "Username";  
        String passphrase = "passphrase";  
        String SFTPWORKINGDIR = "remote directory";    
        String prikeyfile = "C:\\Open SSH Key.ppk";


        Session     session     = null;  
        Channel     channel     = null;  
        ChannelSftp channelSftp = null;  

try{  
        JSch jsch = new JSch();  
        jsch.addIdentity(prikeyfile, passphrase);
        session = jsch.getSession(SFTPUSER,SFTPHOST,SFTPPORT);  
        session.setConfig("StrictHostKeyChecking", "no"); 
        session.connect();  
        channel = session.openChannel("sftp");  
        channel.connect();  
        channelSftp = (ChannelSftp)channel;  
        channelSftp.cd(SFTPWORKINGDIR);  
        byte[] buffer = new byte[1024];  
        BufferedInputStream bis = new BufferedInputStream(channelSftp.get("file.csv"));  
        File newFile = new File("C:\\file.csv"); 
        OutputStream os = new FileOutputStream(newFile);  
        BufferedOutputStream bos = new BufferedOutputStream(os);  
        int readCount;  

while
        ( (readCount = bis.read(buffer)) > 0) {  
        System.out.println("Writing files to disk: " );  
        bos.write(buffer, 0, readCount);  
        }  
        bis.close();  
        bos.close();  
        }catch(Exception ex){  
        ex.printStackTrace();  

        }  

    }      

} 

Answer 1

您可以获取目录列表并遍历它：

    try {
            channel.connect();
            logger.info("shell channel connected....");             
        } catch(JSchException e) {
            logger.warning("Could not connect: " + e.toString());
            logStreamForEmail.close();

        }

        if (!channel.isConnected()) {

            // Close the log stream for email.  This causes it to write all output to the Byte Array Output Stream, which we can dump into email Body Texts
            logStreamForEmail.close();

            // Send warning email, could not connect
            new SendEmail(warningEmailAddress, "SFTP Warning: Could not connect to host", baosForEmail.toString());
        } else {   
            try {   
                ChannelSftp c = (ChannelSftp) channel;   
                c.lcd(localDir);
                logger.info("lcd " + c.lpwd());

                // Get a listing of the remote directory
                @SuppressWarnings("unchecked")
                Vector<ChannelSftp.LsEntry> list = c.ls("."); 
                logger.info("ls .");

                // iterate through objects in list, identifying specific file names
                for (ChannelSftp.LsEntry oListItem : list) {
                    // output each item from directory listing for logs
                    logger.info(oListItem.toString()); 

                    // If it is a file (not a directory)
                    if (!oListItem.getAttrs().isDir()) {
                        // Grab the remote file ([remote filename], [local path/filename to write file to])

                        logger.info("get " + oListItem.getFilename());
                        c.get(oListItem.getFilename(), oListItem.getFilename());  // while testing, disable this or all of your test files will be grabbed

                        grabCount++; 

                        // Delete remote file
                        //c.rm(oListItem.getFilename());  // Note for SFTP grabs from this remote host, deleting the file is unnecessary, 
                                                          //   as their system automatically moves an item to the 'downloaded' subfolder
                                                          //   after it has been grabbed.  For other target hosts, un comment this line to remove any downloaded files from the inbox.
                    }
                }

                // Report files grabbed to log
                if (grabCount == 0) { 
                    logger.info("Found no new files to grab.");
                } else {
                    logger.info("Retrieved " + grabCount + " new files.");
                }                           
            } catch(SftpException e) {
                logger.warning(e.toString());
            } finally {
                // disconnect session.  If this is not done, the job will hang and leave log files locked
                session.disconnect();
                logger.info("Session Closed");
            }

如果你不使用记录器，你可以用 System.out.println 替换所有的 'logger.warning' 和 'logger.info'。

Answer 2

Download & Decrypt file from SFTP using JSCH

/**
 * The class to download the files from SFTP server.
 */
package com.test.service;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.OutputStream;

import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import javax.servlet.ServletContext;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;

import com.jcraft.jsch.Channel;
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;

/**
 * @author varunvikramsingh@gmail.com
 * 
 */
@Service
public class DownloadFileServiceJschImpl implements DownloadFileService {
    @Value("${sftpServer}")
    String sftpServer;

    @Value("${sftpUsername}")
    String sftpUsername;

    @Value("${sftpPassword}")
    String sftpPassword;

    @Value("${sftpPort}")
    String sftpPort;

    @Value("${decryptPrivateKey}")
    String DecryptKeyKey;

    private Log logger = LogFactory.getLog(this.getClass().getName());

    @Override
    public void downloadFile(String ccoid, String reportType, String url, String filename, OutputStream outStream,
            byte[] decryptKeyFromSOA) throws SftpException {

            try {

            // SFTP HOST DETAILS
            String ftpHostSFTP = sftpServer;
            // SFTP PORT NUMBER
            String ftpPortSFTP = sftpPort;
            int parsePort = Integer.parseInt(ftpPortSFTP);
            // SFTP USER NAME
            String ftpUserNameSFTP = sftpUsername.trim();
            // SFTP PASSWORD
            String ftpPasswordSFTP = sftpPassword;
            // SFTP REMOTE DIRECTORY
            String ftpRemoteDirectory = "/data";


            // First Create a JSch session
            logger.info("Creating session with SFTP.");
            // JAVA SECURE CHANNEL API for connecting to the service of via SSH22
            JSch jsch = new JSch();
            Session session = null;
            Channel channel = null;
            ChannelSftp sftpChannel = null;

            logger.info("Trying to Connect to SFTP Server : "+sftpServer);
            logger.info("SFTP Server userName : "+sftpUsername);
            logger.info("SFTP Server sftPort: "+sftpPort);
            logger.info("SFTP Server password: "+sftpPassword);
            session = jsch.getSession(ftpUserNameSFTP, ftpHostSFTP, parsePort);
            //session = jsch.getSession(sftpUsername, sftpServer, sftpPort);
            session.setConfig("StrictHostKeyChecking", "no");
            session.setPassword(ftpPasswordSFTP);
            //session.setPassword(sftpPassword);
            session.connect();

            channel = session.openChannel("sftp");
            channel.connect();
            sftpChannel = (ChannelSftp) channel;
            sftpChannel.cd("/");
            sftpChannel.cd("/data/");

            logger.info("Current Directory for user is : "+ sftpChannel.pwd());
            logger.info("User is trying to download file :"+filename);

            String newFileName = filename+".enc";

            logger.info("Portal added .enc as suffix to filename, fileName now is :"+newFileName);

            // ==============Decrypt SOA key=================
            byte[] decryptedSOAKeyArray = decrypt(decryptKeyFromSOA,readSecurityKey());
            String soaDecryptedKey = new String(decryptedSOAKeyArray);

            logger.info("Private Key Received from SOA :"+soaDecryptedKey);

            logger.info("Reading the file from SFTP server");

            BufferedInputStream bis = new BufferedInputStream(sftpChannel.get(newFileName));  
            BufferedOutputStream bos = new BufferedOutputStream(outStream);

            logger.info("Decrypting the file received from SFTP");

            // Decrypt the file
            decrypt(bis, bos, decryptedSOAKeyArray);

            logger.info("File Successfully Downloaded");

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

            logger.info("All connections successfully closed");

        }
        catch (JSchException e) {
            e.printStackTrace();
        }
        catch (SftpException e) {
            e.printStackTrace();
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Autowired
    ServletContext servletContext;
    private byte[] readSecurityKey() {

        ObjectInputStream in = null;
        byte[] publicKey = null;

        String path = servletContext.getRealPath("/WEB-INF/conf");
        String publicKeyfilename = path + "\\PublicKey.txt";

        logger.info("Reading security Key from file :"+publicKeyfilename);

        try {
            InputStream is = new FileInputStream(publicKeyfilename);
            publicKey = getByteArrayFromFile(is);
        }
        catch (IOException ioe) {
            logger.info("Exception in reading security key "+ioe);
        }
        finally {
            if (null != in) {
                try {
                    in.close();
                }
                catch (IOException e) {
                    /*
                     * Eating this exception since it occurred while closing the input stream.
                     */
                }
            }

        } // end of finally
        return publicKey;
    }

    public static void invokeDecryptFile(String encFilename,String decFilename,byte[] password){
        try{
        BufferedInputStream is = new BufferedInputStream(new FileInputStream(encFilename));
        BufferedOutputStream decout = new BufferedOutputStream(new FileOutputStream(decFilename));
        decrypt(is, decout, password);
        }catch(Exception e){
            e.printStackTrace();
        }
    }


    public static byte[] getByteArrayFromFile(InputStream is) {
        try {
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            int buf_size = 1024;
            byte[] buffer = new byte[buf_size];
            int len = 0;
            while (-1 != (len = is.read(buffer, 0, buf_size))) {
                out.write(buffer, 0, len);
            }
            byte[] fileContent = out.toByteArray();
            is.close();
            return fileContent;
        }
        catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }


    public static byte[] decrypt(byte[] cipherTextBytes, byte[] password) throws Exception {
        ByteArrayInputStream bis = new ByteArrayInputStream(cipherTextBytes);
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        decrypt(bis, bos, password);        
        return bos.toByteArray();
    }

    public static void decrypt(InputStream in, OutputStream out, byte[] password) throws Exception{
        final String ALGORITHM = "AES";
        final String transformation="AES/CFB8/NoPadding";
        final int CACHE_SIZE = 64*1024;
        final int IV_LENGTH=16;
        byte[] iv = new byte[IV_LENGTH];
        in.read(iv);

        Cipher cipher = Cipher.getInstance(transformation); 
        SecretKeySpec keySpec = new SecretKeySpec(password, ALGORITHM);
        IvParameterSpec ivSpec = new IvParameterSpec(iv);
        cipher.init(Cipher.DECRYPT_MODE, keySpec, ivSpec);

        in = new CipherInputStream(in, cipher);
        byte[] buf = new byte[CACHE_SIZE];
        int numRead = 0;
        while ((numRead = in.read(buf)) >= 0) {
            out.write(buf, 0, numRead);
        }
        out.close();
    }

    // @Override
    // public void downloadFile(InputStream in, OutputStream out) {
    // try {
    // int i = 0;
    // byte[] bytesIn = new byte[1024];
    //
    // /*
    // * Loop through the entire file writing bytes.
    // */
    // while ((i = in.read(bytesIn)) >= 0) {
    // out.write(bytesIn, 0, i);
    // }
    //
    // out.close();
    // in.close();
    // }
    // catch(Exception e) {
    // e.printStackTrace();
    // }
    //
    // }


}