Apache Common-net Ftp客户端实例
  本人参考Apache Common-net 2.2 的Api以及官方网的测试代码而写的FTP客户端操作实例，此外引用了dom4j开源包用于将FTP服务器的目录结构保存成XML文件。需实现断点续传的功能，还请高手多多指教。

package com.shine.Ftp.util;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import java.util.List;

import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPClientConfig;
import org.apache.commons.net.ftp.FTPFile;
import org.apache.commons.net.ftp.FTPListParseEngine;
import org.apache.commons.net.ftp.FTPReply;
import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.XMLWriter;

public class FtpHelper {

	private FTPClient ftp = null;
	/**
	 * Ftp服务器
	 */
	private String server;
	/**
	 * 用户名
	 */
	private String uname;
	/**
	 * 密码
	 */
	private String password;
	/**
	 * 连接端口，默认21
	 */
	private int port = 21;
	
	private Document document ;

	public FtpHelper(String server, int port, String uname,
			String password){
		this.server = server;
		if (this.port > 0){
			this.port = port;
		}
		this.uname = uname;
		this.password = password;
		//初始化
		ftp = new FTPClient();	
	}
	/**
	 * 连接FTP服务器
	 * 
	 * @param server
	 * @param uname
	 * @param password
	 * @return
	 * @throws Exception
	 */
	public FTPClient connectFTPServer() throws Exception {
		try {
			ftp.configure(getFTPClientConfig());
			ftp.connect(this.server, this.port);
			if (!ftp.login(this.uname, this.password)) {
				ftp.logout();
				ftp = null;
				return ftp;
			}

			// 文件类型,默认是ASCII
			ftp.setFileType(FTPClient.BINARY_FILE_TYPE);
			ftp.setControlEncoding("GBK");
			// 设置被动模式
			ftp.enterLocalPassiveMode();
			ftp.setConnectTimeout(2000);
			ftp.setBufferSize(1024);
			// 响应信息
			int replyCode = ftp.getReplyCode();
			if ((!FTPReply.isPositiveCompletion(replyCode))) {
				// 关闭Ftp连接
				closeFTPClient();
				// 释放空间
				ftp = null;
				throw new Exception("登录FTP服务器失败,请检查![Server:" + server + "、"
						+ "User:" + uname + "、" + "Password:" + password);
			} else {
				return ftp;
			}
		} catch (Exception e) {
			ftp.disconnect();
			ftp = null;
			throw e;
		}
	}

	/**
	 * 配置FTP连接参数
	 * 
	 * @return
	 * @throws Exception
	 */
	public FTPClientConfig getFTPClientConfig() throws Exception {
		String systemKey = FTPClientConfig.SYST_NT;
		String serverLanguageCode = "zh";
		FTPClientConfig conf = new FTPClientConfig(systemKey);
		conf.setServerLanguageCode(serverLanguageCode);
		conf.setDefaultDateFormatStr("yyyy-MM-dd");
		return conf;
	}

	/**
	 * 向FTP根目录上传文件
	 * 
	 * @param localFile
	 * @param newName
	 *            新文件名
	 * @throws Exception
	 */
	public Boolean uploadFile(String localFile, String newName)
			throws Exception {
		InputStream input = null;
		boolean success = false;
		try {
			File file = null;
			if (checkFileExist(localFile)) {
				file = new File(localFile);
			}
			input = new FileInputStream(file);
			success = ftp.storeFile(newName, input);
			if (!success) {
				throw new Exception("文件上传失败!");
			}
		} catch (Exception e) {
			throw e;
		} finally {
			if (input != null) {
				input.close();
			}
		}
		return success;
	}

	/**
	 * 向FTP根目录上传文件
	 * 
	 * @param input
	 * @param newName
	 *            新文件名
	 * @throws Exception
	 */
	public Boolean uploadFile(InputStream input, String newName)
			throws Exception {
		boolean success = false;
		try {
			success = ftp.storeFile(newName, input);
			if (!success) {
				throw new Exception("文件上传失败!");
			}
		} catch (Exception e) {
			throw e;
		} finally {
			if (input != null) {
				input.close();
			}
		}
		return success;
	}

	/**
	 * 向FTP指定路径上传文件
	 * 
	 * @param localFile
	 * @param newName
	 *            新文件名
	 * @param remoteFoldPath
	 * @throws Exception
	 */
	public Boolean uploadFile(String localFile, St