<!-- https://mvnrepository.com/artifact/com.jcraft/jsch -->
<dependency>
  <groupId>com.jcraft</groupId>
  <artifactId>jsch</artifactId>
  <version>0.1.54</version>
</dependency>

import sun.net.ftp.FtpClient;
import sun.net.ftp.FtpProtocolException;

import java.io.*;
import java.net.InetSocketAddress;
import java.net.SocketAddress;

/**
 * Java自帶的API對(duì)FTP的操作
 */
public class Test {
  private FtpClient ftpClient;

  Test(){
     /*
    使用默認(rèn)的端口號(hào)、用戶名、密碼以及根目錄連接FTP服務(wù)器
     */
    this.connectServer("192.168.56.130", 21, "jiashubing", "123456", "/home/jiashubing/ftp/anonymous/");
  }

  public void connectServer(String ip, int port, String user, String password, String path) {
    try {
      /* ******連接服務(wù)器的兩種方法*******/
      ftpClient = FtpClient.create();
      try {
        SocketAddress addr = new InetSocketAddress(ip, port);
        ftpClient.connect(addr);
        ftpClient.login(user, password.toCharArray());
        System.out.println("login success!");
        if (path.length() != 0) {
          //把遠(yuǎn)程系統(tǒng)上的目錄切換到參數(shù)path所指定的目錄
          ftpClient.changeDirectory(path);
        }
      } catch (FtpProtocolException e) {
        e.printStackTrace();
      }
    } catch (IOException ex) {
      ex.printStackTrace();
      throw new RuntimeException(ex);
    }
  }

  /**
   * 關(guān)閉連接
   */
  public void closeConnect() {
    try {
      ftpClient.close();
      System.out.println("disconnect success");
    } catch (IOException ex) {
      System.out.println("not disconnect");
      ex.printStackTrace();
      throw new RuntimeException(ex);
    }
  }

  /**
   * 上傳文件
   * @param localFile 本地文件
   * @param remoteFile 遠(yuǎn)程文件
   */
  public void upload(String localFile, String remoteFile) {
    File file_in = new File(localFile);
    try(OutputStream os = ftpClient.putFileStream(remoteFile);
      FileInputStream is = new FileInputStream(file_in)) {
      byte[] bytes = new byte[1024];
      int c;
      while ((c = is.read(bytes)) != -1) {
        os.write(bytes, 0, c);
      }
      System.out.println("upload success");
    } catch (IOException ex) {
      System.out.println("not upload");
      ex.printStackTrace();
    } catch (FtpProtocolException e) {
      e.printStackTrace();
    }
  }

  /**
   * 下載文件。獲取遠(yuǎn)程機(jī)器上的文件filename，借助TelnetInputStream把該文件傳送到本地。
   * @param remoteFile 遠(yuǎn)程文件路徑(服務(wù)器端)
   * @param localFile 本地文件路徑(客戶端)
   */
  public void download(String remoteFile, String localFile) {
    File file_in = new File(localFile);
    try(InputStream is = ftpClient.getFileStream(remoteFile);
      FileOutputStream os = new FileOutputStream(file_in)){

      byte[] bytes = new byte[1024];
      int c;
      while ((c = is.read(bytes)) != -1) {
        os.write(bytes, 0, c);
      }
      System.out.println("download success");
    } catch (IOException ex) {
      System.out.println("not download");
      ex.printStackTrace();
    }catch (FtpProtocolException e) {
      e.printStackTrace();
    }
  }

  public static void main(String agrs[]) {
    Test fu = new Test();

    //下載測(cè)試
    String filepath[] = {"aa.xlsx","bb.xlsx"};
    String localfilepath[] = {"E:/lalala/aa.xlsx","E:/lalala/bb.xlsx"};
    for (int i = 0; i < filepath.length; i++) {
      fu.download(filepath[i], localfilepath[i]);
    }
    //上傳測(cè)試
    String localfile = "E:/lalala/tt.xlsx";
    String remotefile = "tt.xlsx";        //上傳
    fu.upload(localfile, remotefile);
    fu.closeConnect();
  }
}

import com.jcraft.jsch.*;

import java.util.Properties;

/**
 * 解釋一下SFTP的整個(gè)調(diào)用過(guò)程，這個(gè)過(guò)程就是通過(guò)Ip、Port、Username、Password獲取一個(gè)Session,
 * 然后通過(guò)Session打開(kāi)SFTP通道（獲得SFTP Channel對(duì)象）,再在建立通道（Channel）連接，最后我們就是
 * 通過(guò)這個(gè)Channel對(duì)象來(lái)調(diào)用SFTP的各種操作方法.總是要記得，我們操作完SFTP需要手動(dòng)斷開(kāi)Channel連接與Session連接。
 * @author jiashubing
 * @since 2018/5/8
 */
public class SftpCustom {

  private ChannelSftp channel;
  private Session session;
  private String sftpPath;

  SftpCustom() {
     /*
     使用端口號(hào)、用戶名、密碼以連接SFTP服務(wù)器
     */
    this.connectServer("192.168.56.130", 22, "jiashubing", "123456", "/home/ftp/");
  }

  SftpCustom(String ftpHost, int ftpPort, String ftpUserName, String ftpPassword, String sftpPath) {
    this.connectServer(ftpHost, ftpPort, ftpUserName, ftpPassword, sftpPath);
  }

  public void connectServer(String ftpHost, int ftpPort, String ftpUserName, String ftpPassword, String sftpPath) {
    try {
      this.sftpPath = sftpPath;

      // 創(chuàng)建JSch對(duì)象
      JSch jsch = new JSch();
      // 根據(jù)用戶名，主機(jī)ip，端口獲取一個(gè)Session對(duì)象
      session = jsch.getSession(ftpUserName, ftpHost, ftpPort);
      if (ftpPassword != null) {
        // 設(shè)置密碼
        session.setPassword(ftpPassword);
      }
      Properties configTemp = new Properties();
      configTemp.put("StrictHostKeyChecking", "no");
      // 為Session對(duì)象設(shè)置properties
      session.setConfig(configTemp);
      // 設(shè)置timeout時(shí)間
      session.setTimeout(60000);
      session.connect();
      // 通過(guò)Session建立鏈接
      // 打開(kāi)SFTP通道
      channel = (ChannelSftp) session.openChannel("sftp");
      // 建立SFTP通道的連接
      channel.connect();
    } catch (JSchException e) {
      //throw new RuntimeException(e);
    }
  }

  /**
   * 斷開(kāi)SFTP Channel、Session連接
   */
  public void closeChannel() {
    try {
      if (channel != null) {
        channel.disconnect();
      }
      if (session != null) {
        session.disconnect();
      }
    } catch (Exception e) {
      //
    }
  }

  /**
   * 上傳文件
   *
   * @param localFile 本地文件
   * @param remoteFile 遠(yuǎn)程文件
   */
  public void upload(String localFile, String remoteFile) {
    try {
      remoteFile = sftpPath + remoteFile;
      channel.put(localFile, remoteFile, ChannelSftp.OVERWRITE);
      channel.quit();
    } catch (SftpException e) {
      //e.printStackTrace();
    }
  }

  /**
   * 下載文件
   *
   * @param remoteFile 遠(yuǎn)程文件
   * @param localFile 本地文件
   */
  public void download(String remoteFile, String localFile) {
    try {
      remoteFile = sftpPath + remoteFile;
      channel.get(remoteFile, localFile);
      channel.quit();
    } catch (SftpException e) {
      //e.printStackTrace();
    }
  }

  public static void main(String[] args) {
    SftpCustom sftpCustom = new SftpCustom();
    //上傳測(cè)試
    String localfile = "E:/lalala/tt.xlsx";
    String remotefile = "/home/ftp/tt2.xlsx";
    sftpCustom.upload(localfile, remotefile);
    //下載測(cè)試
    sftpCustom.download(remotefile, "E:/lalala/tt3.xlsx");
    sftpCustom.closeChannel();
  }
}