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.fileupload2.jakarta.servlet5;
018
019import org.apache.commons.io.FileCleaningTracker;
020
021import jakarta.servlet.ServletContext;
022import jakarta.servlet.ServletContextEvent;
023import jakarta.servlet.ServletContextListener;
024
025/**
026 * A servlet context listener, which ensures that the {@link FileCleaningTracker}'s reaper thread is terminated, when the web application is destroyed.
027 */
028public class JakartaFileCleaner implements ServletContextListener {
029
030    /**
031     * Attribute name, which is used for storing an instance of {@link FileCleaningTracker} in the web application.
032     */
033    public static final String FILE_CLEANING_TRACKER_ATTRIBUTE = JakartaFileCleaner.class.getName() + ".FileCleaningTracker";
034
035    /**
036     * Gets the instance of {@link FileCleaningTracker}, which is associated with the given {@link ServletContext}.
037     *
038     * @param servletContext The servlet context to query
039     * @return The contexts tracker
040     */
041    public static FileCleaningTracker getFileCleaningTracker(final ServletContext servletContext) {
042        return (FileCleaningTracker) servletContext.getAttribute(FILE_CLEANING_TRACKER_ATTRIBUTE);
043    }
044
045    /**
046     * Sets the instance of {@link FileCleaningTracker}, which is associated with the given {@link ServletContext}.
047     *
048     * @param servletContext The servlet context to modify
049     * @param tracker        The tracker to set
050     */
051    public static void setFileCleaningTracker(final ServletContext servletContext, final FileCleaningTracker tracker) {
052        servletContext.setAttribute(FILE_CLEANING_TRACKER_ATTRIBUTE, tracker);
053    }
054
055    /**
056     * Called when the web application is being destroyed. Calls {@link FileCleaningTracker#exitWhenFinished()}.
057     *
058     * @param sce The servlet context, used for calling {@link #getFileCleaningTracker(ServletContext)}.
059     */
060    @Override
061    public void contextDestroyed(final ServletContextEvent sce) {
062        getFileCleaningTracker(sce.getServletContext()).exitWhenFinished();
063    }
064
065    /**
066     * Called when the web application is initialized. Does nothing.
067     *
068     * @param sce The servlet context, used for calling {@link #setFileCleaningTracker(ServletContext, FileCleaningTracker)}.
069     */
070    @Override
071    public void contextInitialized(final ServletContextEvent sce) {
072        setFileCleaningTracker(sce.getServletContext(), new FileCleaningTracker());
073    }
074}