注：调用FTPClient.enterLocalPassiveMode();这个方法的意思就是每次数据连接之前，ftp client告诉ftp server开通一个端口来传输数据。为什么要这样做呢，因为ftp server可能每次开启不同的端口来传输数据，但是在linux上，由于安全限制，可能某些端口没有开启，所以就出现阻塞。
上传下载代码如下：
public class FtpApche { ???private static FTPClient ftpClient = new FTPClient(); ???private static String encoding = System.getProperty("file.encoding");/**??* Description: 从FTP服务器下载文件??* ??* @Version1.0??* @param url??*?? FTP服务器hostname??* @param port??*?? FTP服务器端口??* @param username??*?? FTP登录账号??* @param password??*?? FTP登录密码??* @param remotePath??*?? FTP服务器上的相对路径??* @param fileName??*?? 要下载的文件名??* @param localPath??*?? 下载后保存到本地的路径??* @return */ ???public static boolean downFile(String url, int port, String username, ???String password, String remotePath, String fileName,String localPath) { ???boolean result = false; ???try { ???int reply; ???ftpClient.setControlEncoding(encoding); ???ftpClient.connect(url, port); ???// 如果采用默认端口，可以使用ftp.connect(url)的方式直接连接FTP服务器 ???ftpClient.login(username, password);// 登录 ???// 设置文件传输类型为二进制 ???ftpClient.setFileType(FTPClient.BINARY_FILE_TYPE); ???// 获取ftp登录应答代码 ???reply = ftpClient.getReplyCode(); ???// 验证是否登陆成功 ???if (!FTPReply.isPositiveCompletion(reply)) { ???ftpClient.disconnect(); ???System.err.println("FTP server refused connection."); ???return result; ???} ???// 转移到FTP服务器目录至指定的目录下 ???ftpClient.changeWorkingDirectory(new String(remotePath.getBytes(encoding),"iso-8859-1")); ???ftpClient.enterLocalPassiveMode(); ????// 获取文件列表 ???FTPFile[] fs = ftpClient.listFiles(); ???for (FTPFile ff : fs) { ???if (ff.getName().equals(fileName)) { ???File localFile = new File(localPath + "/" + ff.getName()); ???OutputStream is = new FileOutputStream(localFile); ???ftpClient.retrieveFile(ff.getName(), is); ???is.close(); ???????} ???} ???ftpClient.logout(); ???result = true; ???} catch (IOException e) { ???e.printStackTrace(); ???} finally { ???if (ftpClient.isConnected()) { ???try { ???ftpClient.disconnect(); ???} catch (IOException ioe) { ???} ???} ???} ???return result; ???} ???/**?? ?* 将FTP服务器上文件下载到本地?? ?* ?? ?*/ ???public void testDownFile() { ???try { ???boolean flag = downFile("132.122.237.xxx", 21, "xxx","xxx", "/home/apache-tomcat-7.0.61_2/webapps/crm/", "test.wav", "E:/"); ???System.out.println(flag); ???}catch(Exception e){ ???????e.printStackTrace(); ???}} ???public static void main(String[] args) { ???FtpApche fa = new FtpApche(); ???//下载 ???fa.testDownFile(); ???//上传 ???//fa.testUpLoadFromDisk(); ???} ????public static boolean uploadFile(String url, int port, String username, ??????????????String password, String path, String filename, InputStream input) { ?????????????boolean result = false; ?????????????try { ??????????????int reply; ??????????????// 如果采用默认端口，可以使用ftp.connect(url)的方式直接连接FTP服务器 ??????????????ftpClient.connect(url, port); ??????????????// 登录 ??????????????ftpClient.login(username, password); ??????????????ftpClient.setControlEncoding(encoding); ??????????????// 检验是否连接成功 ??????????????reply = ftpClient.getReplyCode(); ??????????????if (!FTPReply.isPositiveCompletion(reply)) { ???????????????System.out.println("连接失败"); ???????????????ftpClient.disconnect(); ???????????????return result; ??????????????} ??????????????// 转移工作目录至指定目录下 ??????????????boolean change = ftpClient.changeWorkingDirectory(path); ??????????????ftpClient.setFileType(FTP.BINARY_FILE_TYPE); ??????????????if (change) { ???????????????ftpClient.enterLocalPassiveMode(); ????????????????result = ftpClient.storeFile(new String(filename.getBytes(encoding),"iso-8859-1"), input); ???????????????if (result) { ????????????????System.out.println("上传成功!"); ???????????????} ??????????????} ??????????????input.close(); ??????????????ftpClient.logout(); ?????????????} catch (IOException e) { ??????????????e.printStackTrace(); ?????????????} finally { ??????????????if (ftpClient.isConnected()) { ???????????????try { ????????????????ftpClient.disconnect(); ???????????????} catch (IOException ioe) { ???????????????} ??????????????} ?????????????} ?????????????return result; ????????????} ????????????/** ?????????????* 将本地文件上传到FTP服务器上 ?????????????* ??????????????*/ ????????????public void testUpLoadFromDisk() { ?????????????try { ??????????????FileInputStream in = new FileInputStream(new File("E:/test22.wav")); ??????????????boolean flag = uploadFile("132.122.237.xxx", 21, "xxx","xxx", "/home/apache-tomcat-7.0.61_2/webapps/crm/", "test22.txt", in); ??????????????System.out.println(flag); ?????????????} catch (FileNotFoundException e) { ??????????????e.printStackTrace(); ?????????????} ????????????} ????????????}FTP文件上传下载
原文地址：http://blog.51cto.com/1008610086/2350399