com.jdom.mediadownloader.MediaDownloader.java Source code

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Here is the source code for com.jdom.mediadownloader.MediaDownloader.java

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/** 
 *  Copyright (C) 2012  Just Do One More
 *  
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.jdom.mediadownloader;

import java.io.File;
import java.io.FileReader;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Properties;

import com.google.common.io.Closeables;
import org.apache.log4j.lf5.util.StreamUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.jdom.mediadownloader.ApplicationLock.LockException;
import com.jdom.mediadownloader.api.MediaProcessor;
import com.jdom.mediadownloader.api.MediaProcessorRegistry;
import com.jdom.mediadownloader.domain.AbstractEntity;
import com.jdom.mediadownloader.domain.EntityDownload;
import com.jdom.mediadownloader.download.queue.EntityDownloadQueueManager;
import com.jdom.util.time.Duration;

public class MediaDownloader {

    private static final Logger LOG = LoggerFactory.getLogger(MediaDownloader.class);

    private static ClassPathXmlApplicationContext ctx;

    public static void main(String[] args) {
        if (args.length != 1) {
            throw new IllegalArgumentException(
                    "You must pass the location to the properties file to the application!");
        }

        File file = new File(args[0]);

        Properties properties = new Properties();
        FileReader fileReader = null;

        try {
            fileReader = new FileReader(file);
            properties.load(fileReader);
        } catch (Exception e) {
            throw new RuntimeException(e);
        } finally {
            Closeables.closeQuietly(fileReader);
        }

        System.getProperties().putAll(properties);

        initializeContext();

        MediaDownloader mediaDownloader = ctx.getBean(MediaDownloader.class);
        mediaDownloader.processDownloads();
    }

    public static void initializeContext() {
        if (ctx == null) {
            ctx = new ClassPathXmlApplicationContext(
                    new String[] { "/mediadownloader-core.xml", "/mediadownloader-core-db.xml",
                            "/mediadownloader-series.xml", "/mediadownloader-series-db.xml" });
        }
    }

    public static void closeContext() {
        if (ctx != null) {
            ctx.close();
            ctx = null;
        }
    }

    private final MediaProcessorRegistry mediaProcessorRegistry;

    private final ApplicationLock applicationLock;

    private MediaDownloader(ApplicationLock applicationLock, MediaProcessorRegistry mediaProcessorRegistry) {
        this.applicationLock = applicationLock;
        this.mediaProcessorRegistry = mediaProcessorRegistry;
    }

    private void processDownloads() {
        try {
            if (applicationLock.tryLock()) {
                for (MediaProcessor<?, ?> processor : mediaProcessorRegistry.getRegistered()) {
                    try {
                        invokeMediaProcessor(processor);
                    } catch (Exception e) {
                        LOG.error("Exception while processing.", e);
                    }
                }
            } else {
                LOG.warn("Unable to acquire the file lock, does the cron timer need to be lengthened?");
            }
        } catch (LockException e) {
            LOG.error("Unable to acquire the lock", e);
        } finally {
            applicationLock.unlock();
        }
    }

    private <T extends AbstractEntity<T>, U extends EntityDownload<U, T>> void invokeMediaProcessor(
            MediaProcessor<T, U> processor) {
        EntityDownloadQueueManager<T, U> queueManager = processor.getDownloadQueueManager();
        queueManager.purgeExpiredDownloads(processor.getAllowedTimeForDownloadToLive().toMillis().value);

        List<T> entities = processor.getEntities();

        Collection<U> downloads = processor.findDownloads(entities);

        if (!downloads.isEmpty()) {

            // Remove anything currently downloading, and any remaining
            // downloads to the queue
            for (Iterator<U> iter = downloads.iterator(); iter.hasNext();) {

                // Get the entity in question
                U download = iter.next();
                T entity = download.getEntity();

                // First things first, make sure the series is not already in
                // the download queue
                if (queueManager.containsEntity(entity)) {
                    if (LOG.isDebugEnabled()) {
                        LOG.debug(String.format("%s is already in the download queue, skipping...", download));
                    }

                    iter.remove();
                } else {
                    LOG.info(String.format("Added %s to the download queue", download));
                    queueManager.addEntity(entity);
                }
            }

            Duration sleepTimeBetweenDownloads = processor.getSleepTimeBetweenDownloads();

            // Perform the actual downloads
            for (U download : downloads) {
                processor.download(download);

                sleepBetweenDownloads(sleepTimeBetweenDownloads);
            }

        }

        if (LOG.isInfoEnabled()) {
            LOG.info(String.format("Found [%s] downloads for media processor [%s]", downloads.size(),
                    processor.getName()));
        }

        LOG.debug("Checking for successful downloads for processor.");
        List<T> successfulDownloads = processor.processSuccessfulDownloads();

        for (T download : successfulDownloads) {
            // Remove the download from the queue
            if (!(queueManager.removeEntity(download))) {
                LOG.warn(String.format("Unable to remove download %s from the queue", download));
            }
        }
    }

    private void sleepBetweenDownloads(Duration sleepTimeBetweenDownloads) {
        try {
            if (LOG.isDebugEnabled()) {
                LOG.debug(
                        "Sleeping for " + sleepTimeBetweenDownloads.toMillis().value + " ms until next download.");
            }
            sleepTimeBetweenDownloads.sleep();
        } catch (InterruptedException e) {
            LOG.error("Exception while sleeping", e);
        }
    }
}