主要用到两个包：

commons-net-1.4.1.jar
jakarta-oro-2.0.8.jar

 一、

package tmp.ftp;

/**
 * FTP实体Bean
 *
 * @author zhanjia
 *
 */
public class FtpBean {
 // ftpHost
 private java.lang.String ftpHost;

 // ftpPort
 private java.lang.String ftpPort;

 // ftpUser
 private java.lang.String ftpUser;

 // ftpPassword
 private java.lang.String ftpPassword;

 // ftpPath
 private java.lang.String ftpPath;

......

二、FTP测试类

/**
 *
 */
package tmp.ftp;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPFile;
import org.apache.commons.net.ftp.FTPReply;

import examples.PrintCommandListener;

/**
 * FTP测试类
 *
 * @author zhanjia
 *
 */
public class TestFtp {

 private static final Log log = LogFactory.getLog(TestFtp.class);

 /**
  * 测试连接FTP服务器是否成功
  *
  * @param ftpBean
  * @throws Exception
  */
 public static void connectFTP(FtpBean ftpBean) {
  FTPClient ftp = new FTPClient();
  PrintCommandListener listener = new PrintCommandListener(
    new PrintWriter(System.out));
  ftp.addProtocolCommandListener(listener);
  ftp.setDefaultPort(Integer.parseInt(ftpBean.getFtpPort())); // 设置默认端口

  //boolean error = false;
  try {
   int reply;
   ftp.connect(ftpBean.getFtpHost()); // 连接主机
   System.out.println("Connected to " + ftpBean.getFtpHost() + ".");
   // System.out.print(ftp.getReplyString());

   // 尝试连接后, 检查返回码验证是否连接成功
   reply = ftp.getReplyCode();

   if (!FTPReply.isPositiveCompletion(reply)) {
    ftp.disconnect();
    System.err.println("FTP server refused connection.");
    System.exit(1);
   }
   System.out.println("连接成功!");
  } catch (IOException e) {
   if (ftp != null && ftp.isConnected()) {
    try {
     ftp.disconnect();
    } catch (IOException f) {
     // do nothing
    }
   }
   System.err.println("连接服务器失败.");
   e.printStackTrace();
   System.exit(1);
  } finally {
   if (ftp != null && ftp.isConnected()) {
    try {
     ftp.logout();
     ftp.disconnect();
    } catch (IOException e) {
     // do nothing
    }
   }
  }
 }

 /**
  * 获取FTP根目录列表
  *
  * @param ftpBean
  * @return
  * @throws Exception
  */
 public static Map getFTPPathList(FtpBean ftpBean) {
  Map paths = null;
  String fName = null;
  String userName = ftpBean.getFtpUser();
  String password = ftpBean.getFtpPassword();
  /*
   * if (userName.equals("anonymous")) { password = "anonymous"; }
   */

  FTPClient ftp = new FTPClient();
  PrintCommandListener listener = new PrintCommandListener(
    new PrintWriter(System.out));
  ftp.addProtocolCommandListener(listener);
  ftp.setControlEncoding("GBK"); // 设置编码
  ftp.setDefaultPort(Integer.parseInt(ftpBean.getFtpPort())); // 设置默认端口

  try {
   ftp.connect(ftpBean.getFtpHost()); // 连接主机
   System.out.println("连接到 " + ftpBean.getFtpHost() + ".");
   if (ftp.login(userName, password)) { // 登录
    System.out.println("登录成功!");
    System.out.println("FTP目录: " + ftp.printWorkingDirectory());
   } else {
    System.out.println("登录失败!");
   }

   // ftp.type(FTPClient.ASCII_FILE_TYPE);
   FTPFile files[] = ftp.listFiles();
   if (files != null) {
    int a = 0, b = 0;
    paths = new HashMap();
    for (int i = 0; i < files.length; i++) {
     if (files[i].isDirectory()) {
      fName = files[i].getName();
      if (!".".equals(fName) && !"..".equals(fName)) {
       paths.put("目录" + (a++), fName);
      }
     } else if (files[i].isFile()) {
      fName = files[i].getName();
      if (!"<DIR>".equalsIgnoreCase(fName)) {
       paths.put("文件" + (b++), files[i].getName());
      }
     }
    }
   }
  } catch (IOException e) {
   if (ftp != null && ftp.isConnected()) {
    try {
     ftp.disconnect();
    } catch (IOException f) {
     // do nothing
    }
   }
   System.err.println("连接服务器失败.");
   e.printStackTrace();
   System.exit(1);
  } finally {
   if (ftp != null && ftp.isConnected()) {
    try {
     ftp.logout();
     ftp.disconnect();
    } catch (IOException e) {
     // do nothing
    }
   }
  }
  return paths;
 }

 /**
  * @param args
  * @throws Exception
  */
 public static void main(String[] args) throws Exception {
  FtpBean ftpBean = new FtpBean();
  ftpBean.setFtpHost("61.235.112.241");
  ftpBean.setFtpPort("21");
  //ftpBean.setFtpUser("anonymous11");
  ftpBean.setFtpUser("anonymous");
  ftpBean.setFtpPassword("anonymous");

  System.out.println("-- 测试连接 --");
  TestFtp.connectFTP(ftpBean);

  System.out.println();
  System.out.println("-- 获取FTP根目录列表 --");
  Map paths = TestFtp.getFTPPathList(ftpBean);
  System.out.println();
  System.out.println("-- 文件与目录 --");
  if (paths != null) {
   Iterator it = paths.entrySet().iterator();
   while (it.hasNext()) {
    Entry entry = (Entry) it.next();
    String name = (String) entry.getKey();
    String value = (String) entry.getValue();
    System.out.println(name + ": " + value);
   }
  }

 }

}

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