/**
* Copyright 2010 Daniel Guermeur and Amy Unruh
*
* 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.
*
* See http://connectrapp.appspot.com/ for a demo, and links to more information
* about this app and the book that it accompanies.
*/
package com.metadot.book.connectr.server.servlets;
import java.io.IOException;
import java.util.List;
import java.util.logging.Logger;
import javax.jdo.PersistenceManager;
import javax.jdo.Query;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.metadot.book.connectr.server.PMF;
import com.metadot.book.connectr.server.domain.StreamItem;
import com.metadot.book.connectr.server.domain.UserAccount;
import com.metadot.book.connectr.server.utils.ChannelServer;
import com.metadot.book.connectr.shared.messages.ContentAvailableMessage;
/**
* The UserNotifServlet servlet determines whether there is any new content for the feeds
* associated with the Friends of a given user, and if so, sends a push
* notification to the client (if the channel API has been enabled).
* This servlet is enqueued as a task that runs after an update of a user's feeds
*/
@SuppressWarnings("serial")
public class UserNotifServlet extends HttpServlet {
private static Logger logger = Logger.getLogger(UserNotifServlet.class.getName());
private UserAccount getUserAccount(String userId, PersistenceManager pm) {
UserAccount userPrefs = null;
Query q = null;
try {
q = pm.newQuery(UserAccount.class, "uniqueId == :uniqueId");
q.setRange(0,1);
@SuppressWarnings("unchecked") List<UserAccount> results = (List<UserAccount>) q.execute(userId);
if (results.iterator().hasNext()) {
for (UserAccount u : results) {
userPrefs = u;
}
}
}
catch (Exception e) {
e.printStackTrace();
}
finally {
q.closeAll();
}
return userPrefs;
}
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws IOException {
doPost(req, resp);
}
public void doPost(HttpServletRequest req, HttpServletResponse resp)
throws IOException {
PersistenceManager pm = PMF.get().getPersistenceManager();
String userId = req.getParameter("uniqueid");
UserAccount user = null;
Query q = null;
if (!ChannelServer.channelAPIEnabled()) {
return;
}
try {
user = getUserAccount(userId, pm);
logger.info("in UserNotifServlet doPost for user " + user.getId());
if (user != null) {
// see if there exist any stream items associated with that user, newer than the lastReported date
q = pm.newQuery(StreamItem.class, "date > :d1 && ukeys == :u1");
q.setOrdering("date desc");
q.setRange(0, 1);
@SuppressWarnings("unchecked")
List<StreamItem> sitems = (List<StreamItem>) q.execute(user.getLastReported(), user.getId());
if (sitems.iterator().hasNext()) {
// if so (if newer), call pushMessage to trigger the 'push' of the new content notification
StreamItem sitem = sitems.iterator().next();
user.setLastReported(sitem.getDate());
logger.info("pushing 'new content' notification");
ChannelServer.pushMessage(user, new ContentAvailableMessage());
}
}
}
catch (Exception e) {
e.printStackTrace();
}
finally {
if (q != null) {
q.closeAll();
}
pm.close();
}
}
} //end class