org.jasig.portlet.announcements.controller.RssFeedController.java Source code

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Here is the source code for org.jasig.portlet.announcements.controller.RssFeedController.java

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/**
 * Licensed to Apereo under one or more contributor license
 * agreements. See the NOTICE file distributed with this work
 * for additional information regarding copyright ownership.
 * Apereo 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 the following location:
 *
 *   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 org.jasig.portlet.announcements.controller;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import javax.portlet.PortletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.jasig.portlet.announcements.model.Announcement;
import org.jasig.portlet.announcements.model.Topic;
import org.jasig.portlet.announcements.service.IAnnouncementService;
import org.springframework.web.bind.ServletRequestUtils;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.AbstractController;

import com.rometools.rome.feed.synd.SyndContent;
import com.rometools.rome.feed.synd.SyndContentImpl;
import com.rometools.rome.feed.synd.SyndEntry;
import com.rometools.rome.feed.synd.SyndEntryImpl;
import com.rometools.rome.feed.synd.SyndFeed;
import com.rometools.rome.feed.synd.SyndFeedImpl;
import com.rometools.rome.io.FeedException;
import com.rometools.rome.io.SyndFeedOutput;

/**
 * @author Erik A. Olsson (eolsson@uci.edu)
 * 
 * $LastChangedBy$
 * $LastChangedDate$
 *
 */
public class RssFeedController extends AbstractController {

    private IAnnouncementService announcementService;

    private static final String CONTENT_TYPE = "application/rss+xml";

    /* (non-Javadoc)
     * @see org.springframework.web.servlet.mvc.AbstractController#handleRequestInternal(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
     */
    @Override
    protected ModelAndView handleRequestInternal(HttpServletRequest request, HttpServletResponse response)
            throws IllegalStateException, IOException {

        response.setContentType(CONTENT_TYPE);

        Long topicId;
        try {
            topicId = Long.valueOf(ServletRequestUtils.getIntParameter(request, "topic"));
            if (topicId == null) {
                throw new IllegalStateException("Must specify the topic id");
            }
        } catch (Exception e) {
            response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Must specify topic id");
            return null;
        }

        Topic t = null;
        try {
            t = announcementService.getTopic(topicId);
        } catch (PortletException e) {
            e.printStackTrace();
        }

        if (t == null) {
            response.sendError(HttpServletResponse.SC_NOT_FOUND, "no such topic");
            return null;
        }

        if (!t.isAllowRss()) {
            response.sendError(HttpServletResponse.SC_FORBIDDEN, "This topic is not available as RSS");
            return null;
        }

        // fetch and sort the announcements
        List<Announcement> announcements = new ArrayList<Announcement>();
        announcements.addAll(t.getPublishedAnnouncements());

        Collections.sort(announcements);

        // create the feed
        SyndFeed feed = new SyndFeedImpl();
        feed.setFeedType("rss_2.0");
        feed.setTitle(t.getTitle());
        feed.setLink(request.getRequestURL().append("?topic=").append(topicId.toString()).toString());
        feed.setDescription(t.getDescription());

        List<SyndEntry> entries = new ArrayList<SyndEntry>();
        SyndEntry entry;
        SyndContent description;

        for (Announcement a : announcements) {
            entry = new SyndEntryImpl();
            entry.setTitle(a.getTitle());
            entry.setAuthor(a.getAuthor());
            if (a.getLink() != null)
                entry.setLink(a.getLink());
            entry.setPublishedDate(a.getStartDisplay());
            description = new SyndContentImpl();
            description.setType("text/plain");
            description.setValue(a.getMessage());
            entry.setDescription(description);
            entries.add(entry);
        }

        feed.setEntries(entries);

        SyndFeedOutput output = new SyndFeedOutput();
        String out;
        try {
            out = output.outputString(feed);
        } catch (FeedException e) {
            e.printStackTrace();
            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Error generating feed");
            return null;
        }

        response.setContentLength(out.length());
        response.getOutputStream().print(out);
        response.getOutputStream().flush();

        return null;

    }

    /**
     * @param announcementService the announcementService to set
     */
    public void setAnnouncementService(IAnnouncementService announcementService) {
        this.announcementService = announcementService;
    }

}