    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 */
    017package org.apache.commons.fileupload.servlet;
    018
    019import javax.servlet.ServletContext;
    020import javax.servlet.ServletContextListener;
    021import javax.servlet.ServletContextEvent;
    022
    023import org.apache.commons.io.FileCleaningTracker;
    024
    025/**
    026 * A servlet context listener, which ensures that the
    027 * {@link FileCleaningTracker}'s reaper thread is terminated,
    028 * when the web application is destroyed.
    029 */
    030public class FileCleanerCleanup implements ServletContextListener {
    031
    032    /**
    033     * Attribute name, which is used for storing an instance of
    034     * {@link FileCleaningTracker} in the web application.
    035     */
    036    public static final String FILE_CLEANING_TRACKER_ATTRIBUTE
    037        = FileCleanerCleanup.class.getName() + ".FileCleaningTracker";
    038
    039    /**
    040     * Returns the instance of {@link FileCleaningTracker}, which is
    041     * associated with the given {@link ServletContext}.
    042     *
    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     *
    056     * @param pServletContext The servlet context to modify
    057     * @param pTracker The tracker to set
    058     */
    059    public static void setFileCleaningTracker(ServletContext pServletContext,
    060            FileCleaningTracker pTracker) {
    061        pServletContext.setAttribute(FILE_CLEANING_TRACKER_ATTRIBUTE, pTracker);
    062    }
    063
    064    /**
    065     * Called when the web application is initialized. Does
    066     * nothing.
    067     *
    068     * @param sce The servlet context, used for calling
    069     *   {@link #setFileCleaningTracker(ServletContext, FileCleaningTracker)}.
    070     */
    071    @Override
    072    public void contextInitialized(ServletContextEvent sce) {
    073        setFileCleaningTracker(sce.getServletContext(),
    074                new FileCleaningTracker());
    075    }
    076
    077    /**
    078     * Called when the web application is being destroyed.
    079     * Calls {@link FileCleaningTracker#exitWhenFinished()}.
    080     *
    081     * @param sce The servlet context, used for calling
    082     *     {@link #getFileCleaningTracker(ServletContext)}.
    083     */
    084    @Override
    085    public void contextDestroyed(ServletContextEvent sce) {
    086        getFileCleaningTracker(sce.getServletContext()).exitWhenFinished();
    087    }
    088
    089}