1   /*
    2    * $Id: AbstractTilesListener.java 797540 2009-07-24 15:42:00Z apetrelli $
    3    *
    4    * Licensed to the Apache Software Foundation (ASF) under one
    5    * or more contributor license agreements.  See the NOTICE file
    6    * distributed with this work for additional information
    7    * regarding copyright ownership.  The ASF licenses this file
    8    * to you under the Apache License, Version 2.0 (the
    9    * "License"); you may not use this file except in compliance
   10    * with the License.  You may obtain a copy of the License at
   11    *
   12    * http://www.apache.org/licenses/LICENSE-2.0
   13    *
   14    * Unless required by applicable law or agreed to in writing,
   15    * software distributed under the License is distributed on an
   16    * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   17    * KIND, either express or implied.  See the License for the
   18    * specific language governing permissions and limitations
   19    * under the License.
   20    */
   21   package org.apache.tiles.web.startup;
   22   
   23   import javax.servlet.ServletContext;
   24   import javax.servlet.ServletContextEvent;
   25   import javax.servlet.ServletContextListener;
   26   
   27   import org.apache.tiles.TilesException;
   28   import org.apache.tiles.servlet.context.ServletTilesApplicationContext;
   29   import org.apache.tiles.servlet.context.ServletUtil;
   30   import org.apache.tiles.startup.TilesInitializer;
   31   import org.slf4j.Logger;
   32   import org.slf4j.LoggerFactory;
   33   
   34   /**
   35    * Listener for the initialization of the Tiles container.
   36    *
   37    * @version $Rev: 797540 $ $Date: 2009-07-24 17:42:00 +0200 (ven, 24 lug 2009) $
   38    */
   39   public abstract class AbstractTilesListener implements ServletContextListener {
   40   
   41       /**
   42        * Log instance.
   43        */
   44       private Logger log = LoggerFactory.getLogger(AbstractTilesListener.class);
   45   
   46       /**
   47        * The initializer object.
   48        *
   49        * @since 2.1.2
   50        */
   51       protected TilesInitializer initializer;
   52   
   53       /**
   54        * Initialize the TilesContainer and place it
   55        * into service.
   56        *
   57        * @param event The intercepted event.
   58        */
   59       public void contextInitialized(ServletContextEvent event) {
   60           ServletContext servletContext = event.getServletContext();
   61           initializer = createTilesInitializer();
   62           initializer.initialize(new ServletTilesApplicationContext(
   63                   servletContext));
   64       }
   65   
   66       /**
   67        * Remove the tiles container from service.
   68        *
   69        * @param event The intercepted event.
   70        */
   71       public void contextDestroyed(ServletContextEvent event) {
   72           ServletContext servletContext = event.getServletContext();
   73           try {
   74               ServletUtil.setContainer(servletContext, null);
   75           } catch (TilesException e) {
   76               log.warn("Unable to remove tiles container from service.", e);
   77           }
   78       }
   79   
   80       /**
   81        * Creates a new instance of {@link TilesInitializer}. Implement it to use a
   82        * different initializer.
   83        *
   84        * @return The Tiles servlet-based initializer.
   85        * @since 2.2.0
   86        */
   87       protected abstract TilesInitializer createTilesInitializer();
   88   }