001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.commons.fileupload.servlet;
018    
019    import javax.servlet.ServletContext;
020    import javax.servlet.ServletContextListener;
021    import javax.servlet.ServletContextEvent;
022    
023    import org.apache.commons.io.FileCleaningTracker;
024    
025    /**
026     * A servlet context listener, which ensures that the
027     * {@link org.apache.commons.io.FileCleaner FileCleaner's}
028     * reaper thread is terminated,
029     * when the web application is destroyed.
030     *
031     * @version $Id: FileCleanerCleanup.java 1454691 2013-03-09 12:15:54Z simonetripodi $
032     */
033    public class FileCleanerCleanup implements ServletContextListener {
034    
035        /**
036         * Attribute name, which is used for storing an instance of
037         * {@link FileCleaningTracker} in the web application.
038         */
039        public static final String FILE_CLEANING_TRACKER_ATTRIBUTE
040            = FileCleanerCleanup.class.getName() + ".FileCleaningTracker";
041    
042        /**
043         * Returns the instance of {@link FileCleaningTracker}, which is
044         * associated with the given {@link ServletContext}.
045         *
046         * @param pServletContext The servlet context to query
047         * @return The contexts tracker
048         */
049        public static FileCleaningTracker
050                getFileCleaningTracker(ServletContext pServletContext) {
051            return (FileCleaningTracker)
052                pServletContext.getAttribute(FILE_CLEANING_TRACKER_ATTRIBUTE);
053        }
054    
055        /**
056         * Sets the instance of {@link FileCleaningTracker}, which is
057         * associated with the given {@link ServletContext}.
058         *
059         * @param pServletContext The servlet context to modify
060         * @param pTracker The tracker to set
061         */
062        public static void setFileCleaningTracker(ServletContext pServletContext,
063                FileCleaningTracker pTracker) {
064            pServletContext.setAttribute(FILE_CLEANING_TRACKER_ATTRIBUTE, pTracker);
065        }
066    
067        /**
068         * Called when the web application is initialized. Does
069         * nothing.
070         *
071         * @param sce The servlet context, used for calling
072         *   {@link #setFileCleaningTracker(ServletContext, FileCleaningTracker)}.
073         */
074        public void contextInitialized(ServletContextEvent sce) {
075            setFileCleaningTracker(sce.getServletContext(),
076                    new FileCleaningTracker());
077        }
078    
079        /**
080         * Called when the web application is being destroyed.
081         * Calls {@link FileCleaningTracker#exitWhenFinished()}.
082         *
083         * @param sce The servlet context, used for calling
084         *     {@link #getFileCleaningTracker(ServletContext)}.
085         */
086        public void contextDestroyed(ServletContextEvent sce) {
087            getFileCleaningTracker(sce.getServletContext()).exitWhenFinished();
088        }
089    
090    }