/* 
    P/P   *  Method: void net.sourceforge.pebble.aggregator.NewsFeedContextListener$1(NewsFeedContextListener)
          */
     1  /*
     2   * Copyright (c) 2003-2006, Simon Brown
     3   * All rights reserved.
     4   *
     5   * Redistribution and use in source and binary forms, with or without
     6   * modification, are permitted provided that the following conditions are met:
     7   *
     8   *   - Redistributions of source code must retain the above copyright
     9   *     notice, this list of conditions and the following disclaimer.
    10   *
    11   *   - Redistributions in binary form must reproduce the above copyright
    12   *     notice, this list of conditions and the following disclaimer in
    13   *     the documentation and/or other materials provided with the
    14   *     distribution.
    15   *
    16   *   - Neither the name of Pebble nor the names of its contributors may
    17   *     be used to endorse or promote products derived from this software
    18   *     without specific prior written permission.
    19   *
    20   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    21   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    22   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    23   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
    24   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
    25   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
    26   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
    27   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
    28   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
    29   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    30   * POSSIBILITY OF SUCH DAMAGE.
    31   */
    32  package net.sourceforge.pebble.aggregator;
    33  
    34  import org.apache.commons.logging.Log;
    35  import org.apache.commons.logging.LogFactory;
    36  
         /* 
    P/P   *  Method: void net.sourceforge.pebble.aggregator.NewsFeedContextListener()
          */
    37  import javax.servlet.ServletContextListener;
    38  import javax.servlet.ServletContextEvent;
    39  import java.util.Timer;
    40  import java.util.TimerTask;
    41  
    42  /**
    43   * Manages a timer that regularly updates all news feeds that have been
    44   * subscribed to.
    45   *
    46   * @author    Simon Brown
    47   */
    48  public class NewsFeedContextListener implements ServletContextListener {
    49  
    50    private static final long ONE_MINUTE = 1000 * 60;
           /* 
    P/P     *  Method: Log access$0()
            * 
            *  Postconditions:
            *    init'ed(return_value)
            */
    51    private static final Log log = LogFactory.getLog(NewsFeedContextListener.class);
    52  
    53    private Timer timer;
    54  
    55    public void contextInitialized(ServletContextEvent servletContextEvent) {
             /* 
    P/P       *  Method: void contextInitialized(ServletContextEvent)
              * 
              *  Presumptions:
              *    org.apache.commons.logging.LogFactory:getLog(...)@51 != null
              * 
              *  Postconditions:
              *    this.timer == &new Timer(contextInitialized#1)
              *    new Timer(contextInitialized#1) num objects == 1
              */
    56      log.info("Starting newsfeed updater");
    57      timer = new Timer();
    58      timer.scheduleAtFixedRate(new TimerTask() {
    59        public void run() {
    60          try {
                   /* 
    P/P             *  Method: void run()
                    * 
                    *  Presumptions:
                    *    org.apache.commons.logging.LogFactory:getLog(...)@51 != null
                    */
    61            NewsFeedCache.getInstance().refreshFeeds();
    62          } catch (Exception e) {
    63            log.error("Error while refreshing feeds " + e.getMessage());
    64            e.printStackTrace();
    65          }
    66        }
    67      }, 0, ONE_MINUTE * 15);
    68    }
    69  
    70    public void contextDestroyed(ServletContextEvent servletContextEvent) {
             /* 
    P/P       *  Method: void contextDestroyed(ServletContextEvent)
              * 
              *  Preconditions:
              *    this.timer != null
              * 
              *  Presumptions:
              *    org.apache.commons.logging.LogFactory:getLog(...)@51 != null
              */
    71      log.info("Stopping newsfeed updater");
    72      timer.cancel();
    73    }
    74  
    75  }