org.jppf.example.ftp.service.FTPClientWrapper.java Source code

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Here is the source code for org.jppf.example.ftp.service.FTPClientWrapper.java

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/*
 * JPPF.
 * Copyright (C) 2005-2014 JPPF Team.
 * http://www.jppf.org
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.jppf.example.ftp.service;

import java.io.*;

import org.apache.commons.net.ftp.*;

/**
 * Implementation of a file server client that uses the FTP client provided
 * by the Apache Commons Net library.
 * @see <a href="http://commons.apache.org/net">Apache Commons Net</a>
 * @author Laurent Cohen
 */
public class FTPClientWrapper {
    /**
     * The underlying FTP client.
     */
    private FTPClient ftpClient;

    /**
     * Open a secure ftp connection with the specified parameters.
     * @param host the host where the FTP server is running
     * @param port the secure FTP port.
     * @param user username to use.
     * @param password the user password.
     * @throws Exception if any error occurs.
     */
    public void open(final String host, final int port, final String user, final String password) throws Exception {
        // create with implicit TLS
        ftpClient = new FTPSClient(true);
        ftpClient.connect(host, port);
        ftpClient.login(user, password);
    }

    /**
     * Disconnect from the FTP server and close the connection.
     * @throws Exception if any error occurs.
     */
    public void close() throws Exception {
        try {
            ftpClient.logout();
        } catch (IOException e) {
            System.err.println("error logging off the ftp client: " + e.getMessage());
        }
        try {
            ftpClient.disconnect();
        } catch (IOException e) {
            System.err.println("error disconnecting from the ftp client: " + e.getMessage());
        }
        ftpClient = null;
    }

    /**
     * Download a file from a remote FTP server.
     * @param localPath the path to the resulting local file.
     * @param remotePath the path of the remote file.
     * @throws Exception if any error occurs during the file transfer.
     */
    public void download(final String localPath, final String remotePath) throws Exception {
        BufferedOutputStream bos = null;
        try {
            bos = new BufferedOutputStream(new FileOutputStream(localPath));
            ftpClient.retrieveFile(remotePath, bos);
        } finally {
            if (bos != null)
                bos.close();
        }
    }

    /**
     * Upload a local file to a remote FTP server.
     * @param localPath the path to the file to upload.
     * @param remotePath the path of the resulting remote file.
     * @throws Exception if any error occurs during the file transfer.
     */
    public void upload(final String localPath, final String remotePath) throws Exception {
        BufferedInputStream bis = null;
        try {
            bis = new BufferedInputStream(new FileInputStream(localPath));
            ftpClient.storeFile(remotePath, bis);
        } finally {
            if (bis != null)
                bis.close();
        }
    }

    /**
     * Get the underlying FTP client.
     * <br/>If this method is called before {@link #open() open()} has been invoked, the returned object will be null.
     * @return  an <code>FTPClient</code> instance.
     */
    public FTPClient getFtpClient() {
        return ftpClient;
    }
}