com.knowbout.epg.processor.Downloader.java Source code

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Here is the source code for com.knowbout.epg.processor.Downloader.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 com.knowbout.epg.processor;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.InetAddress;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPFile;
import org.apache.commons.net.ftp.FTPReply;

public class Downloader {

    private static final Log log = LogFactory.getLog(Downloader.class);

    private InetAddress server;
    private File destinationFolder;
    private String username;
    private String password;
    private String remoteWorkingDirectory;
    private boolean forceDownload;
    private FTPClient client;

    public Downloader(InetAddress server, String username, String password, File destinationFolder,
            String remoteWorkingDirectory, boolean forceDownload) {
        this.server = server;
        this.destinationFolder = destinationFolder;
        if (!destinationFolder.exists() || !destinationFolder.isDirectory()) {
            throw new IllegalArgumentException(
                    "The destinationFolder must exist and be a directory: " + destinationFolder);
        }
        this.username = username;
        this.password = password;
        this.remoteWorkingDirectory = remoteWorkingDirectory;
        this.forceDownload = forceDownload;
        client = new FTPClient();
    }

    public boolean downloadFile(String filename) throws IOException {
        connect();
        try {
            FTPFile[] files = client.listFiles(filename);
            if (files != null && files.length == 1) {
                return downloadFile(files[0]);
            }
            return false;
        } finally {
            disconnect();
        }
    }

    public int downloadFiles(List<String> fileNames) throws IOException {
        connect();
        int downloads = 0;
        try {
            for (String filename : fileNames) {
                FTPFile[] files = client.listFiles(filename);
                if (files != null && files.length == 1) {
                    if (downloadFile(files[0])) {
                        downloads++;
                    }
                }
            }
        } finally {
            disconnect();
        }
        return downloads;
    }

    public int downloadFiles() throws IOException {
        connect();
        int downloads = 0;
        try {
            log.debug("DownloadFiles, about to list files");

            FTPFile[] files = client.listFiles();
            log.debug("Filelisting: " + files.length);
            for (FTPFile file : files) {
                log.debug("About to download the file: " + file.getName());
                if (downloadFile(file)) {
                    downloads++;
                }
            }
        } finally {
            disconnect();
        }
        return downloads;
    }

    private void disconnect() throws IOException {
        client.logout();
        client.disconnect();
    }

    private void connect() throws IOException {
        client.connect(server);
        boolean loggedIn = client.login(username, password);
        client.enterLocalPassiveMode();
        log.debug("Able to log into " + server + "? " + loggedIn);
        client.setFileType(FTP.BINARY_FILE_TYPE);
        client.changeWorkingDirectory(remoteWorkingDirectory);
        client.setReaderThread(false);
        log.debug("Working directory: " + client.printWorkingDirectory());
    }

    private boolean downloadFile(FTPFile remoteFile) throws IOException {
        boolean success = false;
        File file = new File(destinationFolder + File.separator + remoteFile.getName());
        long lastModified = remoteFile.getTimestamp().getTimeInMillis();
        log.debug("Remote file is " + remoteFile.getName() + " local file is " + file.getAbsoluteFile()
                + " does it exist:" + file.exists());
        if (forceDownload || !file.exists() || (file.lastModified() < lastModified)) {
            log.debug("Downloading " + remoteFile.getName() + " " + remoteFile.getSize() + " to "
                    + file.getAbsolutePath());

            FileOutputStream fos = new FileOutputStream(file);
            client.retrieveFile(remoteFile.getName(), fos);
            fos.close();
            fos.flush();
            file.setLastModified(lastModified);
            success = true;
        }
        return success;
    }

    public static void main(String[] args) throws Exception {
        InetAddress server = InetAddress.getByName("ftp.tmstv.com");
        File destinationFolder = new File("data/samples");
        Downloader downloader = new Downloader(server, "kno868cb", "FYS141ca", destinationFolder, "pub", false);
        int count = downloader.downloadFiles();
        System.err.println("Downloaded " + count + " files");
    }
}