/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements.  See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License.  You may obtain a copy of the License at * *      http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package org.apache.commons.fileupload.servlet;import javax.servlet.ServletContext;import javax.servlet.ServletContextListener;import javax.servlet.ServletContextEvent;import org.apache.commons.io.FileCleaningTracker;/** * A servlet context listener, which ensures that the * {@link org.apache.commons.io.FileCleaner FileCleaner's} * reaper thread is terminated, * when the web application is destroyed. */public class FileCleanerCleanup implements ServletContextListener {    /**     * Attribute name, which is used for storing an instance of     * {@link FileCleaningTracker} in the web application.     */    public static final String FILE_CLEANING_TRACKER_ATTRIBUTE        = FileCleanerCleanup.class.getName() + ".FileCleaningTracker";    /**     * Returns the instance of {@link FileCleaningTracker}, which is     * associated with the given {@link ServletContext}.     * @param pServletContext The servlet context to query     * @return The contexts tracker     */    public static FileCleaningTracker            getFileCleaningTracker(ServletContext pServletContext) {        return (FileCleaningTracker)            pServletContext.getAttribute(FILE_CLEANING_TRACKER_ATTRIBUTE);    }    /**     * Sets the instance of {@link FileCleaningTracker}, which is     * associated with the given {@link ServletContext}.     * @param pServletContext The servlet context to modify     * @param pTracker The tracker to set     */    public static void setFileCleaningTracker(ServletContext pServletContext,            FileCleaningTracker pTracker) {        pServletContext.setAttribute(FILE_CLEANING_TRACKER_ATTRIBUTE, pTracker);    }    /**     * Called when the web application is initialized. Does     * nothing.     * @param sce The servlet context, used for calling     *   {@link #setFileCleaningTracker(ServletContext, FileCleaningTracker)}.     */    public void contextInitialized(ServletContextEvent sce) {        setFileCleaningTracker(sce.getServletContext(),                new FileCleaningTracker());    }    /**     * Called when the web application is being destroyed.     * Calls {@link FileCleaningTracker#exitWhenFinished()}.     * @param sce The servlet context, used for calling     *     {@link #getFileCleaningTracker(ServletContext)}.     */    public void contextDestroyed(ServletContextEvent sce) {        getFileCleaningTracker(sce.getServletContext()).exitWhenFinished();    }}