一个java 下载FTP( Linux)服务器文件夹的例子

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPClientConfig;
import org.apache.commons.net.ftp.FTPFile;

public class DownFTPFile {

 private String hostname;
 private String username;
 private String password;
 private String localBaseDir; 
 private String remoteBaseDir; 
 

 private static FTPClient ftpClient = new FTPClient();
 
 public static void main(String[] args) {
  String hostname = "172.18.72.66";
  String username = "sfdc3";
  String password = "sfdcadmin";
  String localBaseDir = "c:/temp/";
  String remoteBaseDir = "ptsinstall/v3.20.06";
  
  DownFTPFile downFTPClient = new DownFTPFile();
  downFTPClient.setHostname(hostname);
  downFTPClient.setUsername(username);
  downFTPClient.setPassword(password);
  downFTPClient.setLocalBaseDir(localBaseDir);
  downFTPClient.setRemoteBaseDir(remoteBaseDir);
  downFTPClient.startDown();
 }
 
 private void startDown() {
  try {
   ftpClient.connect(hostname);
   ftpClient.login(username, password);
   FTPClientConfig conf = new FTPClientConfig( FTPClientConfig.SYST_UNIX);
   ftpClient.configure(conf);
  } catch (Exception e1) {
   e1.printStackTrace();
  }

  try {
   FTPFile[] files = null;
   boolean changedir = ftpClient.changeWorkingDirectory(remoteBaseDir);
   if ( changedir ){
    files = ftpClient.listFiles();
    for (int i = 0; i < files.length; i++) {
     downloadFile(files[i], localBaseDir, remoteBaseDir);
    }
   }
  } catch (Exception e) {
   System.out.println(e);
  }
 }

 private void downloadFile(FTPFile ftpFile, String relativeLocalPath,String relativeRemotePath) {
  if (ftpFile.isFile()) {//down file
   if (ftpFile.getName().indexOf("?") == -1) {
    OutputStream outputStream = null;
    try {
     outputStream = new FileOutputStream(relativeLocalPath+ ftpFile.getName());
     ftpClient.retrieveFile(ftpFile.getName(), outputStream);
     outputStream.flush();
     outputStream.close();
    } catch (Exception e) {
     System.err.println( e );
    } finally {
     try {
      if (outputStream != null)
       outputStream.close();
     } catch (IOException e) {
      System.out.println("ShowasaFile");
     }
    }
   }
  } else { //deal dirctory
   String newlocalRelatePath = relativeLocalPath + ftpFile.getName();
   String newRemote = new String(relativeRemotePath+ ftpFile.getName().toString());
   
   File fl = new File(newlocalRelatePath);
   if (!fl.exists()) {
    fl.mkdirs();
   }
   try {
    newlocalRelatePath = newlocalRelatePath + '/';
    newRemote = newRemote + "/";
    String currentWorkDir = ftpFile.getName().toString();
    //enter relative workdirectory
    boolean changedir = ftpClient.changeWorkingDirectory(currentWorkDir);
    if (changedir) {
     FTPFile[] files = null;
     files = ftpClient.listFiles();
     for (int i = 0; i < files.length; i++) {
      downloadFile(files[i], newlocalRelatePath, newRemote);
     }
    }
    //return parent directory
    if (changedir)
     ftpClient.changeToParentDirectory();
   } catch (Exception e) {
    System.out.println(e);
   }
  }
 }

 public String getHostname() {
  return hostname;
 }

 public void setHostname(String hostname) {
  this.hostname = hostname;
 }

 public String getPassword() {
  return password;
 }

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

 public String getUsername() {
  return username;
 }

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

 public String getLocalBaseDir() {
  return localBaseDir;
 }

 public void setLocalBaseDir(String localBaseDir) {
  this.localBaseDir = localBaseDir;
 }

 public String getRemoteBaseDir() {
  return remoteBaseDir;
 }

 public void setRemoteBaseDir(String remoteBaseDir) {
  this.remoteBaseDir = remoteBaseDir;
 }
}