Detailed explanation of JAVA SFTP file upload, download and batch download example codes

This article mainly introduces JAVA SFTPfileupload, download and batch download examples. It has certain reference value and interested friends can refer to it.

1.jsch officialAPIView address (the attachment is the required jar)

http: //www.jcraft.com/jsch/

2.jschIntroduction

JSch (Java Secure Channel) is an SSH2 Pure Java implementation. It allows you to connect to an SSH server and use port forwarding, X11 forwarding, file transfer, etc. Of course, you can also integrate its functionality into your own applications.

SFTP(Secure File Transfer Protocol)SecureFile Transfer Protocol. Provides a secure encryption method for transferring files. SFTP is part of SSH and is a secure way to transfer files to the server, but the transfer efficiency is lower than ordinary FTP.

3. API commonly used methods:

• put(): File upload

• get ():       File download

• cd():        Enter the specified directory

• ls():        Get the specified directory File list

• rename(): Rename the specified file or directory

• rm(): Deletespecified file

• mkdir(): Create directory

• rmdir(): Delete directory

• Both put and get have multiple overloaded methods, look at the source code yourself

4. Use and encapsulation of common methods Into a util class

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Properties;
import java.util.Vector;
import org.apache.log4j.Logger;
import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelSftp;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.Session;
import com.jcraft.jsch.SftpATTRS;
import com.jcraft.jsch.SftpException;
import com.jcraft.jsch.ChannelSftp.LsEntry;
/**
 * sftp工具类
 * 
 * @author xxx
 * @date 2014-6-17
 * @time 下午1:39:44
 * @version 1.0
 */
public class SFTPUtils
{
  private static Logger log = Logger.getLogger(SFTPUtils.class.getName());

  private String host;//服务器连接ip
  private String username;//用户名
  private String password;//密码
  private int port = 22;//端口号
  private ChannelSftp sftp = null;
  private Session sshSession = null;

  public SFTPUtils(){}

  public SFTPUtils(String host, int port, String username, String password)
  {
    this.host = host;
    this.username = username;
    this.password = password;
    this.port = port;
  }

  public SFTPUtils(String host, String username, String password)
  {
    this.host = host;
    this.username = username;
    this.password = password;
  }

  /**
   * 通过SFTP连接服务器
   */
  public void connect()
  {
    try
    {
      JSch jsch = new JSch();
      jsch.getSession(username, host, port);
      sshSession = jsch.getSession(username, host, port);
      if (log.isInfoEnabled())
      {
        log.info("Session created.");
      }
      sshSession.setPassword(password);
      Properties sshConfig = new Properties();
      sshConfig.put("StrictHostKeyChecking", "no");
      sshSession.setConfig(sshConfig);
      sshSession.connect();
      if (log.isInfoEnabled())
      {
        log.info("Session connected.");
      }
      Channel channel = sshSession.openChannel("sftp");
      channel.connect();
      if (log.isInfoEnabled())
      {
        log.info("Opening Channel.");
      }
      sftp = (ChannelSftp) channel;
      if (log.isInfoEnabled())
      {
        log.info("Connected to " + host + ".");
      }
    }
    catch (Exception e)
    {
      e.printStackTrace();
    }
  }

  /**
   * 关闭连接
   */
  public void disconnect()
  {
    if (this.sftp != null)
    {
      if (this.sftp.isConnected())
      {
        this.sftp.disconnect();
        if (log.isInfoEnabled())
        {
          log.info("sftp is closed already");
        }
      }
    }
    if (this.sshSession != null)
    {
      if (this.sshSession.isConnected())
      {
        this.sshSession.disconnect();
        if (log.isInfoEnabled())
        {
          log.info("sshSession is closed already");
        }
      }
    }
  }

  /**
   * 批量下载文件
   * @param remotPath：远程下载目录(以路径符号结束,可以为相对路径eg:/assess/sftp/jiesuan_2/2014/)
   * @param localPath：本地保存目录(以路径符号结束,D:\Duansha\sftp\)
   * @param fileFormat：下载文件格式(以特定字符开头,为空不做检验)
   * @param fileEndFormat：下载文件格式(文件格式)
   * @param del：下载后是否删除sftp文件
   * @return
   */
  public List<String> batchDownLoadFile(String remotePath, String localPath,
      String fileFormat, String fileEndFormat, boolean del)
  {
    List<String> filenames = new ArrayList<String>();
    try
    {
      // connect();
      Vector v = listFiles(remotePath);
      // sftp.cd(remotePath);
      if (v.size() > 0)
      {
        System.out.println("本次处理文件个数不为零,开始下载...fileSize=" + v.size());
        Iterator it = v.iterator();
        while (it.hasNext())
        {
          LsEntry entry = (LsEntry) it.next();
          String filename = entry.getFilename();
          SftpATTRS attrs = entry.getAttrs();
          if (!attrs.isDir())
          {
            boolean flag = false;
            String localFileName = localPath + filename;
            fileFormat = fileFormat == null ? "" : fileFormat
                .trim();
            fileEndFormat = fileEndFormat == null ? ""
                : fileEndFormat.trim();
            // 三种情况
            if (fileFormat.length() > 0 && fileEndFormat.length() > 0)
            {
              if (filename.startsWith(fileFormat) && filename.endsWith(fileEndFormat))
              {
                flag = downloadFile(remotePath, filename,localPath, filename);
                if (flag)
                {
                  filenames.add(localFileName);
                  if (flag && del)
                  {
                    deleteSFTP(remotePath, filename);
                  }
                }
              }
            }
            else if (fileFormat.length() > 0 && "".equals(fileEndFormat))
            {
              if (filename.startsWith(fileFormat))
              {
                flag = downloadFile(remotePath, filename, localPath, filename);
                if (flag)
                {
                  filenames.add(localFileName);
                  if (flag && del)
                  {
                    deleteSFTP(remotePath, filename);
                  }
                }
              }
            }
            else if (fileEndFormat.length() > 0 && "".equals(fileFormat))
            {
              if (filename.endsWith(fileEndFormat))
              {
                flag = downloadFile(remotePath, filename,localPath, filename);
                if (flag)
                {
                  filenames.add(localFileName);
                  if (flag && del)
                  {
                    deleteSFTP(remotePath, filename);
                  }
                }
              }
            }
            else
            {
              flag = downloadFile(remotePath, filename,localPath, filename);
              if (flag)
              {
                filenames.add(localFileName);
                if (flag && del)
                {
                  deleteSFTP(remotePath, filename);
                }
              }
            }
          }
        }
      }
      if (log.isInfoEnabled())
      {
        log.info("download file is success:remotePath=" + remotePath
            + "and localPath=" + localPath + ",file size is"
            + v.size());
      }
    }
    catch (SftpException e)
    {
      e.printStackTrace();
    }
    finally
    {
      // this.disconnect();
    }
    return filenames;
  }

  /**
   * 下载单个文件
   * @param remotPath：远程下载目录(以路径符号结束)
   * @param remoteFileName：下载文件名
   * @param localPath：本地保存目录(以路径符号结束)
   * @param localFileName：保存文件名
   * @return
   */
  public boolean downloadFile(String remotePath, String remoteFileName,String localPath, String localFileName)
  {
    FileOutputStream fieloutput = null;
    try
    {
      // sftp.cd(remotePath);
      File file = new File(localPath + localFileName);
      // mkdirs(localPath + localFileName);
      fieloutput = new FileOutputStream(file);
      sftp.get(remotePath + remoteFileName, fieloutput);
      if (log.isInfoEnabled())
      {
        log.info("===DownloadFile:" + remoteFileName + " success from sftp.");
      }
      return true;
    }
    catch (FileNotFoundException e)
    {
      e.printStackTrace();
    }
    catch (SftpException e)
    {
      e.printStackTrace();
    }
    finally
    {
      if (null != fieloutput)
      {
        try
        {
          fieloutput.close();
        }
        catch (IOException e)
        {
          e.printStackTrace();
        }
      }
    }
    return false;
  }

  /**
   * 上传单个文件
   * @param remotePath：远程保存目录
   * @param remoteFileName：保存文件名
   * @param localPath：本地上传目录(以路径符号结束)
   * @param localFileName：上传的文件名
   * @return
   */
  public boolean uploadFile(String remotePath, String remoteFileName,String localPath, String localFileName)
  {
    FileInputStream in = null;
    try
    {
      createDir(remotePath);
      File file = new File(localPath + localFileName);
      in = new FileInputStream(file);
      sftp.put(in, remoteFileName);
      return true;
    }
    catch (FileNotFoundException e)
    {
      e.printStackTrace();
    }
    catch (SftpException e)
    {
      e.printStackTrace();
    }
    finally
    {
      if (in != null)
      {
        try
        {
          in.close();
        }
        catch (IOException e)
        {
          e.printStackTrace();
        }
      }
    }
    return false;
  }

  /**
   * 批量上传文件
   * @param remotePath：远程保存目录
   * @param localPath：本地上传目录(以路径符号结束)
   * @param del：上传后是否删除本地文件
   * @return
   */
  public boolean bacthUploadFile(String remotePath, String localPath,
      boolean del)
  {
    try
    {
      connect();
      File file = new File(localPath);
      File[] files = file.listFiles();
      for (int i = 0; i < files.length; i++)
      {
        if (files[i].isFile()
            && files[i].getName().indexOf("bak") == -1)
        {
          if (this.uploadFile(remotePath, files[i].getName(),
              localPath, files[i].getName())
              && del)
          {
            deleteFile(localPath + files[i].getName());
          }
        }
      }
      if (log.isInfoEnabled())
      {
        log.info("upload file is success:remotePath=" + remotePath
            + "and localPath=" + localPath + ",file size is "
            + files.length);
      }
      return true;
    }
    catch (Exception e)
    {
      e.printStackTrace();
    }
    finally
    {
      this.disconnect();
    }
    return false;

  }

  /**
   * 删除本地文件
   * @param filePath
   * @return
   */
  public boolean deleteFile(String filePath)
  {
    File file = new File(filePath);
    if (!file.exists())
    {
      return false;
    }

    if (!file.isFile())
    {
      return false;
    }
    boolean rs = file.delete();
    if (rs && log.isInfoEnabled())
    {
      log.info("delete file success from local.");
    }
    return rs;
  }

  /**
   * 创建目录
   * @param createpath
   * @return
   */
  public boolean createDir(String createpath)
  {
    try
    {
      if (isDirExist(createpath))
      {
        this.sftp.cd(createpath);
        return true;
      }
      String pathArry[] = createpath.split("/");
      StringBuffer filePath = new StringBuffer("/");
      for (String path : pathArry)
      {
        if (path.equals(""))
        {
          continue;
        }
        filePath.append(path + "/");
        if (isDirExist(filePath.toString()))
        {
          sftp.cd(filePath.toString());
        }
        else
        {
          // 建立目录
          sftp.mkdir(filePath.toString());
          // 进入并设置为当前目录
          sftp.cd(filePath.toString());
        }

      }
      this.sftp.cd(createpath);
      return true;
    }
    catch (SftpException e)
    {
      e.printStackTrace();
    }
    return false;
  }

  /**
   * 判断目录是否存在
   * @param directory
   * @return
   */
  public boolean isDirExist(String directory)
  {
    boolean isDirExistFlag = false;
    try
    {
      SftpATTRS sftpATTRS = sftp.lstat(directory);
      isDirExistFlag = true;
      return sftpATTRS.isDir();
    }
    catch (Exception e)
    {
      if (e.getMessage().toLowerCase().equals("no such file"))
      {
        isDirExistFlag = false;
      }
    }
    return isDirExistFlag;
  }

  /**
   * 删除stfp文件
   * @param directory：要删除文件所在目录
   * @param deleteFile：要删除的文件
   * @param sftp
   */
  public void deleteSFTP(String directory, String deleteFile)
  {
    try
    {
      // sftp.cd(directory);
      sftp.rm(directory + deleteFile);
      if (log.isInfoEnabled())
      {
        log.info("delete file success from sftp.");
      }
    }
    catch (Exception e)
    {
      e.printStackTrace();
    }
  }

  /**
   * 如果目录不存在就创建目录
   * @param path
   */
  public void mkdirs(String path)
  {
    File f = new File(path);

    String fs = f.getParent();

    f = new File(fs);

    if (!f.exists())
    {
      f.mkdirs();
    }
  }

  /**
   * 列出目录下的文件
   * 
   * @param directory：要列出的目录
   * @param sftp
   * @return
   * @throws SftpException
   */
  public Vector listFiles(String directory) throws SftpException
  {
    return sftp.ls(directory);
  }

  public String getHost()
  {
    return host;
  }

  public void setHost(String host)
  {
    this.host = host;
  }

  public String getUsername()
  {
    return username;
  }

  public void setUsername(String username)
  {
    this.username = username;
  }

  public String getPassword()
  {
    return password;
  }

  public void setPassword(String password)
  {
    this.password = password;
  }

  public int getPort()
  {
    return port;
  }

  public void setPort(int port)
  {
    this.port = port;
  }

  public ChannelSftp getSftp()
  {
    return sftp;
  }

  public void setSftp(ChannelSftp sftp)
  {
    this.sftp = sftp;
  }
  
  /**测试*/
  public static void main(String[] args)
  {
    SFTPUtils sftp = null;
    // 本地存放地址
    String localPath = "D:/tomcat5/webapps/ASSESS/DocumentsDir/DocumentTempDir/txtData/";
    // Sftp下载路径
    String sftpPath = "/home/assess/sftp/jiesuan_2/2014/";
    List<String> filePathList = new ArrayList<String>();
    try
    {
      sftp = new SFTPUtils("10.163.201.115", "tdcp", "tdcp");
      sftp.connect();
      // 下载
      sftp.batchDownLoadFile(sftpPath, localPath, "ASSESS", ".txt", true);
    }
    catch (Exception e)
    {
      e.printStackTrace();
    }
    finally
    {
      sftp.disconnect();
    }
  }
}

5. Take a note of the auxiliary class you need, and you can use it directly next time

/**
 * 时间处理工具类（简单的）
 * @author Aaron
 * @date 2014-6-17
 * @time 下午1:39:44
 * @version 1.0
 */
public class DateUtil {
   /**
   * 默认时间字符串的格式
   */
  public static final String DEFAULT_FORMAT_STR = "yyyyMMddHHmmss";
  
  public static final String DATE_FORMAT_STR = "yyyyMMdd";
  
  /**
   * 获取系统时间的昨天
   * @return
   */
  public static String getSysTime(){
     Calendar ca = Calendar.getInstance();  
     ca.set(Calendar.DATE, ca.get(Calendar.DATE)-1);
     Date d = ca.getTime();
     SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
     String a = sdf.format(d);
    return a;
  }
  
  /**
   * 获取当前时间
   * @param date
   * @return
   */
  public static String getCurrentDate(String formatStr)
  {
    if (null == formatStr)
    {
      formatStr=DEFAULT_FORMAT_STR;
    }
    return date2String(new Date(), formatStr);
  }
  
  /**
   * 返回年月日
   * @return yyyyMMdd
   */
  public static String getTodayChar8(String dateFormat){
    return DateFormatUtils.format(new Date(), dateFormat);
  }
  
  /**
   * 将Date日期转换为String
   * @param date
   * @param formatStr
   * @return
   */
  public static String date2String(Date date, String formatStr)
  {
    if (null == date || null == formatStr)
    {
      return "";
    }
    SimpleDateFormat df = new SimpleDateFormat(formatStr);

    return df.format(date);
  }
}

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