从远程ftp上按修改时间或文件名称更新相关文件（原创）

package com.bj.ftp;

/**
 *需要ftp4j.jar
 *author http://faithlee.iteye.com
 */

import it.sauronsoftware.ftp4j.FTPAbortedException;
import it.sauronsoftware.ftp4j.FTPClient;
import it.sauronsoftware.ftp4j.FTPDataTransferException;
import it.sauronsoftware.ftp4j.FTPException;
import it.sauronsoftware.ftp4j.FTPFile;
import it.sauronsoftware.ftp4j.FTPIllegalReplyException;
import it.sauronsoftware.ftp4j.FTPListParseException;

import java.io.File;
import java.io.IOException;
http://faithlee.iteye.com
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import com.bj.util.CommonStringDateUtil;
import com.bj.util.PropertiesUtil;

public class FtpTool {
	
	private FTPClient client = new FTPClient();
	
	/**
	 * 连接且登录到特定的FTP服务器文件夹
	 * 
	 * @return
	 * @throws FTPException
	 * @throws FTPIllegalReplyException
	 * @throws IOException
	 * @throws IllegalStateException
	 */
	public boolean connectToServer(PropertiesUtil pro,String filename) throws IllegalStateException, IOException,
			FTPIllegalReplyException, FTPException {
		
		String server = pro.getValue(filename, "ftp.ip");
		String user = pro.getValue(filename, "ftp.user");
		String password = pro.getValue(filename, "ftp.password");
		String path = pro.getValue(filename, "ftp.path");

		client.connect(server);
		client.login(user, password);
		System.out.println("登陆成功");

		client.changeDirectory(path);

		if (client.isCompressionSupported()) {
			client.setCompressionEnabled(true);
		}
		return true;
	}

	/**http://faithlee.iteye.com
	 * // 根据修改时间更新相同文件名的文件 
	 * public boolean doUpdate() throws
	 * IllegalStateException, IOException, FTPIllegalReplyException,
	 * FTPException, FTPDataTransferException, FTPAbortedException,
	 * FTPListParseException { Boolean bl = null; 
	 * Map<String,FileObject> remotefiles = getRemotefiles(); 
	 * Map<String,FileObject> localfiles = getLocalfiles(); 
	 * // 按远程文件信息对比本地文件信息 
	 * Iterator it= remotefiles.keySet().iterator(); 
	 * while (it.hasNext()) 
	 * { String key =(String) it.next(); 
	 * FileObject localFile = localfiles.get(key);
	 * FileObject remoteFile = remotefiles.get(key); 
	 * if (localFile == null &&remoteFile != null) 
	 * { doDownload(remotefiles); bl = true;} 
	 * //根据本地和远程文件的最后修改时间判断下不下载。 
	 * Date localFileTime =CommonStringDateUtil.parse(localFile.lasttime); 
	 * Date remoteFileTime =CommonStringDateUtil .parse(remoteFile.lasttime); 
	 * if(localFileTime.before(remoteFileTime)) { 
	 * delete();doDownload(remotefiles); bl = true; } 
	 * else { bl = false; }
	 * } return bl; }
	 */
	
	/**
	 根据文件名变化更新文件
	 */
	public boolean doUpdate(String localdir) throws IllegalStateException, IOException,
			FTPIllegalReplyException, FTPException, FTPDataTransferException,
			FTPAbortedException, FTPListParseException {
		Boolean bl = false;
		// 取远程文件信息
		Map<String, FileObject> remotefiles = getRemotefiles();
		// 取本地文件信息
		Map<String, FileObject> localfiles = getLocalfiles(localdir);
		// 按远程文件信息对比本地文件信息

		if (localfiles.size() == 0 && remotefiles.size() != 0) {
			System.out.println("本地为空");
			bl = true;
			System.out.println("开始下载远程文件");
			doDownload(remotefiles,localdir);
			System.out.println("下载完成");
		} else {
			Iterator<String> it = remotefiles.keySet().iterator();
			while (it.hasNext()) {
				String key = (String) it.next();

				if (!localfiles.containsKey(key)) {

					System.out.println("需要更新");
					System.gc();
					delete(localdir);
					System.out.println("删除完成");
					System.out.println("开始下载新文件");
					doDownload(remotefiles,localdir);
					System.out.println("下载完成");
					bl = true;
					break;
				} else {
					bl = false;
				}
			}
		}
		return bl;
	}

	/**
	 * 取服务器文件
	 * 
	 * @return
	 * @throws FTPListParseException
	 * @throws FTPAbortedException
	 * @throws FTPDataTransferException
	 * @throws FTPException
	 * @throws FTPIllegalReplyException
	 * @throws IOException
	 * @throws IllegalStateException
	 */

	private  Map<String, FileObject> getRemotefiles()
			throws IllegalStateException, IOException,
			FTPIllegalReplyException, FTPException, FTPDataTransferException,
			FTPAbortedException, FTPListParseException {
		FTPFile[] files = client.list();
		Map<String, FileObject> rtn = new HashMap<String, FileObject>();
		for (FTPFile file : files) {
			if (".".equals(file.getName()) || "..".equals(file.getName())) {
				continue;
			}
			FileObject o = new FileObject();
			o.filename = file.getName();
			o.lasttime = CommonStringDateUtil.format(file.getModifiedDate());

			rtn.put(o.filename, o);
		}
		return rtn;
	}

	/**
	 * 取本地文件夹的所有文件信息
	 * 
	 * @return
	 */
	private  Map<String, FileObject> getLocalfiles(String localdir) {
		File f = new File(localdir);
		if (!f.exists()) {
			System.out.println("目录不存在，创建目录");
			f.mkdirs();
		}
		Map<String, FileObject> rtn = new HashMap<String, FileObject>();
		if (f.isDirectory()) {
			for (File file : f.listFiles()) {
				FileObject fo = new FileObject();
				fo.filename = file.getName();
				fo.lasttime = CommonStringDateUtil.format(new Date(file
						.lastModified()));
				rtn.put(fo.filename, fo);
			}
		}

		return rtn;
	}

	/**
	 * 删除本地文件
	 * 
	 */
	private void delete(String localdir) {
		File f = new File(localdir);
		File delFile[] = f.listFiles();
		int i = f.listFiles().length;
		
		for (int j = 0; j < i; j++) {
			delFile[j].delete();
		}
	}

	/**
	 * 下载ftp服务器文件
	 */
	private  void doDownload(Map<String, FileObject> remotefiles ,String localdir)
			throws IllegalStateException, IOException,
			FTPIllegalReplyException, FTPException, FTPDataTransferException,
			FTPAbortedException {

		for (String filename : remotefiles.keySet()) {

			client.download(filename, new File(localdir + filename));

		}
	}

	public void close() throws IllegalStateException, IOException,
			FTPIllegalReplyException, FTPException {

		client.disconnect(true);

	}

}

class FileObject {
	String filename;
	String lasttime;

	@Override
	public String toString() {
		return filename + "|" + lasttime;
	}
}