    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    /**
    027     * A servlet context listener, which ensures that the
    028     * {@link org.apache.commons.io.FileCleaner FileCleaner's}
    029     * reaper thread is terminated,
    030     * when the web application is destroyed.
    031     */
    032    public class FileCleanerCleanup implements ServletContextListener {
    033        /**
    034         * Attribute name, which is used for storing an instance of
    035         * {@link FileCleaningTracker} in the web application.
    036         */
    037        public static final String FILE_CLEANING_TRACKER_ATTRIBUTE
    038            = FileCleanerCleanup.class.getName() + ".FileCleaningTracker";
    039
    040        /**
    041         * Returns the instance of {@link FileCleaningTracker}, which is
    042         * associated with the given {@link ServletContext}.
    043         * @param pServletContext The servlet context to query
    044         * @return The contexts tracker
    045         */
    046        public static FileCleaningTracker
    047                getFileCleaningTracker(ServletContext pServletContext) {
    048            return (FileCleaningTracker)
    049                pServletContext.getAttribute(FILE_CLEANING_TRACKER_ATTRIBUTE);
    050        }
    051
    052        /**
    053         * Sets the instance of {@link FileCleaningTracker}, which is
    054         * associated with the given {@link ServletContext}.
    055         * @param pServletContext The servlet context to modify
    056         * @param pTracker The tracker to set
    057         */
    058        public static void setFileCleaningTracker(ServletContext pServletContext,
    059                FileCleaningTracker pTracker) {
    060            pServletContext.setAttribute(FILE_CLEANING_TRACKER_ATTRIBUTE, pTracker);
    061        }
    062
    063        /**
    064         * Called when the web application is initialized. Does
    065         * nothing.
    066         * @param sce The servlet context, used for calling
    067         *   {@link #setFileCleaningTracker(ServletContext, FileCleaningTracker)}.
    068         */
    069        public void contextInitialized(ServletContextEvent sce) {
    070            setFileCleaningTracker(sce.getServletContext(),
    071                    new FileCleaningTracker());
    072        }
    073
    074        /**
    075         * Called when the web application is being destroyed.
    076         * Calls {@link FileCleaningTracker#exitWhenFinished()}.
    077         * @param sce The servlet context, used for calling
    078         *     {@link #getFileCleaningTracker(ServletContext)}.
    079         */
    080        public void contextDestroyed(ServletContextEvent sce) {
    081            getFileCleaningTracker(sce.getServletContext()).exitWhenFinished();
    082        }
    083    }