apache commons-net可以很方便的实现，但是这个第三方包中对文件夹的删除与创建（级联）操作并不是特别的方便。删除文件夹必须保证该文件夹下没有任何 文件，创建文件夹也必须要求父文件夹存在。为了方便以后使用方便，对其进行了简单的封装，主要针对删除与文件夹创建。代码如下：

    package cn.androiddevelop.io;                import java.io.FileInputStream;        import java.io.FileOutputStream;        import java.io.IOException;        import java.net.SocketException;                import org.apache.commons.net.ftp.FTP;        import org.apache.commons.net.ftp.FTPClient;        import org.apache.commons.net.ftp.FTPFile;                /**        * ftp客户端        *         * @author Yuedong Li        *         */        public class FtpClient {            private FTPClient client;                    public FtpClient(String host, String userName, String password)                    throws SocketException, IOException {                initFtpClient(host, 21, userName, password);            }                    public FtpClient(String host, int port, String userName, String password)                    throws SocketException, IOException {                initFtpClient(host, port, userName, password);            }                    /**            * 登录            *             * @param host            * @param port            * @param userName            * @param password            * @throws SocketException            * @throws IOException            */            public void initFtpClient(String host, int port, String userName,                    String password) throws SocketException, IOException {                client = new FTPClient();                client.connect(host, port);                client.login(userName, password);            }                    /**            * 得到所有目录            *             * @param remotePath            * @return            * @throws IOException            */            public FTPFile[] listFiles(String remotePath) throws IOException {                if (client == null)                    return null;                client.changeWorkingDirectory(remotePath);                return client.listFiles();            }                    /**            * 上传            *             * @param localPath            *            本地路径            * @param remotePath            *            ftp路径            * @return 上传是否成功            * @throws IOException            */            public boolean upload(String localPath, String remotePath)                    throws IOException {                if (client == null)                    return false;                boolean res = false;                FileInputStream fileInputStream = new FileInputStream(localPath);                int index = remotePath.lastIndexOf('/');                if (index != -1) {                    client.setFileType(FTP.BINARY_FILE_TYPE);                    client.changeWorkingDirectory(remotePath.substring(0, index));                    res = client.storeFile(remotePath.substring(index + 1),                            fileInputStream);                }                fileInputStream.close();                return res;            }                    /**            * 下载            *             * @param remotePath            *            ftp路径            * @param localPath            *            本地路径            * @return 下载是否成功            * @throws IOException            */            public boolean download(String remotePath, String localPath)                    throws IOException {                if (client == null)                    return false;                boolean res = false;                FileOutputStream fileOutputStream = new FileOutputStream(localPath);                res = client.retrieveFile(remotePath, fileOutputStream);                fileOutputStream.flush();                fileOutputStream.close();                return res;                    }                    /**            * 删除文件            *             * @param remotePath ftp端路径            * @return            * @throws IOException            */            public boolean delete(String remotePath) throws IOException {                if (client == null)                    return false;                        return client.deleteFile(remotePath) || deleteDirectory(remotePath);            }                    /**            * 创建目录            *             * @param remotePath            * @throws IOException            */            public boolean makeDirectory(String remotePath) throws IOException {                if (client == null)                    return false;                        String[] item = remotePath.split("/");                String currentPath = "";                for (int i = 0; i < item.length - 1; i++) {                    currentPath = currentPath + "/" + item[i];                    client.makeDirectory(currentPath);                }                        return client.makeDirectory(remotePath);            }                            /**            * 删除文件            *             * @param remotePath ftp端路径            * @return            * @throws IOException            */            private boolean deleteDirectory(String remotePath) throws IOException {                FTPFile[] files = listFiles(remotePath);                for (int i = 0; i < files.length; i++) {                    if (files[i].isDirectory()) {                        deleteDirectory(remotePath + "/" + files[i].getName());                    } else {                        client.deleteFile(remotePath + "/" + files[i].getName());                    }                }                return client.removeDirectory(remotePath);            }                    /**            * 重命名            *             * @param remoteOldPath             * @param remoteNewPath            * @return            * @throws IOException            */            public boolean rename(String remoteOldPath, String remoteNewPath)                    throws IOException {                if (client == null)                    return false;                return client.rename(remoteOldPath, remoteNewPath);            }                    /**            * 退出登录            *             * @throws IOException            */            public void close() throws IOException {                if (client != null)                    client.logout();            }        }