Java tutorial
/* * Copyright (c) 2011 Enrico Franchi, Michele Tomaiuolo and University of Parma. * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package net.blogracy.controller; import java.io.File; import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; import java.security.InvalidParameterException; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; import java.text.DateFormat; import java.text.SimpleDateFormat; import java.util.TimeZone; import java.util.ArrayList; import java.util.Date; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Map.Entry; import javax.jms.Connection; import javax.jms.ConnectionFactory; import javax.jms.DeliveryMode; import javax.jms.Destination; import javax.jms.Message; import javax.jms.MessageConsumer; import javax.jms.MessageListener; import javax.jms.MessageProducer; import javax.jms.Session; import javax.jms.TextMessage; import net.blogracy.config.Configurations; import net.blogracy.util.FileUtils; import org.apache.activemq.ActiveMQConnection; import org.apache.activemq.ActiveMQConnectionFactory; import org.apache.commons.codec.binary.Base32; import org.apache.shindig.protocol.conversion.BeanConverter; import org.apache.shindig.protocol.conversion.BeanJsonConverter; import org.apache.shindig.social.core.model.ActivityEntryImpl; import org.apache.shindig.social.core.model.ActivityObjectImpl; import org.apache.shindig.social.core.model.AlbumImpl; import org.apache.shindig.social.core.model.MediaItemImpl; import org.apache.shindig.social.opensocial.model.ActivityEntry; import org.apache.shindig.social.opensocial.model.ActivityObject; import org.apache.shindig.social.opensocial.model.Album; import org.apache.shindig.social.opensocial.model.MediaItem; import org.apache.shindig.social.opensocial.model.MediaItem.Type; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import org.json.JSONTokener; import com.google.inject.Binder; import com.google.inject.Guice; import com.google.inject.Module; import com.google.inject.name.Names; /** * Generic functions to manipulate feeds are defined in this class. */ public class ActivitiesController { static final DateFormat ISO_DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'"); static final String CACHE_FOLDER = Configurations.getPathConfig().getCachedFilesDirectoryPath(); private static final FileSharing sharing = FileSharing.getSingleton(); private static final DistributedHashTable dht = DistributedHashTable.getSingleton(); private static final ActivitiesController theInstance = new ActivitiesController(); private static BeanJsonConverter CONVERTER = new BeanJsonConverter(Guice.createInjector(new Module() { @Override public void configure(Binder b) { b.bind(BeanConverter.class).annotatedWith(Names.named("shindig.bean.converter.json")) .to(BeanJsonConverter.class); } })); public static ActivitiesController getSingleton() { return theInstance; } public ActivitiesController() { ISO_DATE_FORMAT.setTimeZone(TimeZone.getTimeZone("UTC")); } static public List<ActivityEntry> getFeed(String user) { List<ActivityEntry> result = new ArrayList<ActivityEntry>(); System.out.println("Getting feed: " + user); JSONObject record = dht.getRecord(user); if (record != null) { try { String latestHash = FileSharing.getHashFromMagnetURI(record.getString("uri")); File dbFile = new File(CACHE_FOLDER + File.separator + latestHash + ".json"); if (!dbFile.exists() && record.has("prev")) { latestHash = FileSharing.getHashFromMagnetURI(record.getString("prev")); dbFile = new File(CACHE_FOLDER + File.separator + latestHash + ".json"); } if (dbFile.exists()) { System.out.println("Getting feed: " + dbFile.getAbsolutePath()); JSONObject db = new JSONObject(new JSONTokener(new FileReader(dbFile))); JSONArray items = db.getJSONArray("items"); for (int i = 0; i < items.length(); ++i) { JSONObject item = items.getJSONObject(i); ActivityEntry entry = (ActivityEntry) CONVERTER.convertToObject(item, ActivityEntry.class); result.add(entry); } System.out.println("Feed loaded"); } else { System.out.println("Feed not found"); } } catch (Exception e) { e.printStackTrace(); } } return result; } public void addFeedEntry(String id, String text, File attachment) { try { String hash = sharing.hash(text); File textFile = new File(CACHE_FOLDER + File.separator + hash + ".txt"); FileWriter w = new FileWriter(textFile); w.write(text); w.close(); String textUri = sharing.seed(textFile); String attachmentUri = null; if (attachment != null) { attachmentUri = sharing.seed(attachment); } final List<ActivityEntry> feed = getFeed(id); final ActivityEntry entry = new ActivityEntryImpl(); entry.setVerb("post"); entry.setUrl(textUri); entry.setPublished(ISO_DATE_FORMAT.format(new Date())); entry.setContent(text); if (attachment != null) { ActivityObject enclosure = new ActivityObjectImpl(); enclosure.setUrl(attachmentUri); entry.setObject(enclosure); } feed.add(0, entry); String feedUri = seedActivityStream(id, feed); DistributedHashTable.getSingleton().store(id, feedUri, entry.getPublished()); } catch (Exception e) { e.printStackTrace(); } } public String seedActivityStream(String userId, final List<ActivityEntry> feed) throws JSONException, IOException { final File feedFile = new File(CACHE_FOLDER + File.separator + userId + ".json"); JSONArray items = new JSONArray(); for (int i = 0; i < feed.size(); ++i) { JSONObject item = new JSONObject(feed.get(i)); items.put(item); } JSONObject db = new JSONObject(); db.put("items", items); FileWriter writer = new FileWriter(feedFile); db.write(writer); writer.close(); String feedUri = sharing.seed(feedFile); return feedUri; } }