au.edu.usq.fascinator.harvester.feed.FeedHarvester.java Source code

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Here is the source code for au.edu.usq.fascinator.harvester.feed.FeedHarvester.java

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package au.edu.usq.fascinator.harvester.feed;

/* 
 * The Fascinator - Plugin - Harvester - Test Harvester
 * Copyright (C) 2009 University of Southern Queensland
 * 
 * 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 2 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

import java.io.File;
import java.io.IOException;
import java.io.StringWriter;
import java.net.MalformedURLException;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.ServiceLoader;

import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import au.edu.usq.fascinator.HarvestClient;
import au.edu.usq.fascinator.api.Configurable;
import au.edu.usq.fascinator.api.PluginException;
import au.edu.usq.fascinator.api.harvester.Harvester;
import au.edu.usq.fascinator.api.harvester.HarvesterException;
import au.edu.usq.fascinator.api.storage.DigitalObject;
import au.edu.usq.fascinator.common.JsonConfig;
import au.edu.usq.fascinator.contrib.feedreader.FeedReader;
import au.edu.usq.fascinator.contrib.feedreader.FeedReaderStateChangeEvent;
import au.edu.usq.fascinator.contrib.feedreader.ItemListener;

import com.sun.syndication.feed.synd.SyndEntry;
import com.sun.syndication.fetcher.FetcherEvent;

/**
 * @author dickinso
 * 
 */
public class FeedHarvester extends ItemListener implements Harvester, Configurable {

    /**
     * 
     */
    private JsonConfig config;

    private static String template = null;

    /**
     * 
     */
    private HashSet<FeedReader> feeds;

    private String cacheDirectory;

    /**
     * 
     */
    private boolean moreObjects = true;

    List<DigitalObject> latestFeedItems;

    /** Logging */
    private static Logger log = LoggerFactory.getLogger(FeedHarvester.class);

    /*
     * (non-Javadoc)
     * 
     * @see au.edu.usq.fascinator.api.Plugin#getId()
     */
    public String getId() {
        return "feed-harvester";
    }

    /*
     * (non-Javadoc)
     * 
     * @see au.edu.usq.fascinator.api.Plugin#getName()
     */
    public String getName() {
        return Messages.getString("harvester-plugin-description");
    }

    public static void setTemplate(String templateFile) {
        template = templateFile;
    }

    public static String getTemplate() {
        return template;
    }

    /*
     * (non-Javadoc)
     * 
     * @see au.edu.usq.fascinator.api.Plugin#init(java.io.File)
     */
    public void init(File jsonFile) throws PluginException {
        try {
            config = new JsonConfig(jsonFile);
        } catch (IOException ioe) {
            throw new HarvesterException(ioe);
        }
        // Load the list of requested URLs
        List<Object> urlList = config.getList("harvester/feed-harvester/urls");
        // Load the cache location
        cacheDirectory = config.get("harvester/feed-harvester/cache", "");
        FeedHarvester.setTemplate(config.get("harvester/feed-harvester/template", ""));
        feeds = new HashSet<FeedReader>();

        // Now iterate through the urls and create FeedReaders
        for (Object feed : urlList) {
            try {
                FeedReader reader = new FeedReader((String) feed, cacheDirectory);
                reader.addFeedReaderStateChangeListener(this);
                feeds.add(reader);
            } catch (MalformedURLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (java.lang.ClassCastException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }

    /*
     * (non-Javadoc)
     * 
     * @see au.edu.usq.fascinator.api.harvester.Harvester#getObjects()
     */
    public List<DigitalObject> getObjects() throws HarvesterException {
        latestFeedItems = new ArrayList<DigitalObject>();

        for (FeedReader feed : feeds) {
            feed.read();
        }

        moreObjects = false;
        return latestFeedItems;
    }

    public void feedReaderStateChangeEvent(FeedReaderStateChangeEvent event) {
        super.feedReaderStateChangeEvent(event);
        if (FetcherEvent.EVENT_TYPE_FEED_RETRIEVED.equals(event.getEventType())) {
            for (SyndEntry entry : (List<SyndEntry>) this.getFeed().getEntries()) {
                latestFeedItems.add(new FeedItemDigitalObject(entry));
            }
        }
    }

    /*
     * (non-Javadoc)
     * 
     * @see au.edu.usq.fascinator.api.harvester.Harvester#hasMoreObjects()
     */
    public boolean hasMoreObjects() {
        return moreObjects;
    }

    /*
     * (non-Javadoc)
     * 
     * @see au.edu.usq.fascinator.api.Plugin#shutdown()
     */
    public void shutdown() throws PluginException {
    }

    /*
     * (non-Javadoc)
     * 
     * @see au.edu.usq.fascinator.api.Configurable#getConfig()
     */
    public String getConfig() {
        StringWriter writer = new StringWriter();
        try {
            IOUtils.copy(getClass().getResourceAsStream("/" + getId() + "-config.html"), writer);
        } catch (IOException ioe) {
            writer.write("<span class=\"error\">" + ioe.getMessage() + "</span>");
        }
        return writer.toString();
    }

    public static void main(String[] args) {
        HarvestClient.main(args);
    }

}