    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.io;
    018
    019    import java.io.File;
    020
    021    /**
    022     * Keeps track of files awaiting deletion, and deletes them when an associated
    023     * marker object is reclaimed by the garbage collector.
    024     * <p>
    025     * This utility creates a background thread to handle file deletion.
    026     * Each file to be deleted is registered with a handler object.
    027     * When the handler object is garbage collected, the file is deleted.
    028     * <p>
    029     * In an environment with multiple class loaders (a servlet container, for
    030     * example), you should consider stopping the background thread if it is no
    031     * longer needed. This is done by invoking the method
    032     * {@link #exitWhenFinished}, typically in
    033     * {@link javax.servlet.ServletContextListener#contextDestroyed} or similar.
    034     *
    035     * @author Noel Bergman
    036     * @author Martin Cooper
    037     * @version $Id: FileCleaner.java 723969 2008-12-06 11:00:40Z sebb $
    038     * @deprecated Use {@link FileCleaningTracker}
    039     */
    040    @Deprecated
    041    public class FileCleaner {
    042        /**
    043         * The instance to use for the deprecated, static methods.
    044         */
    045        static final FileCleaningTracker theInstance = new FileCleaningTracker();
    046
    047        //-----------------------------------------------------------------------
    048        /**
    049         * Track the specified file, using the provided marker, deleting the file
    050         * when the marker instance is garbage collected.
    051         * The {@link FileDeleteStrategy#NORMAL normal} deletion strategy will be used.
    052         *
    053         * @param file  the file to be tracked, not null
    054         * @param marker  the marker object used to track the file, not null
    055         * @throws NullPointerException if the file is null
    056         * @deprecated Use {@link FileCleaningTracker#track(File, Object)}.
    057         */
    058        @Deprecated
    059        public static void track(File file, Object marker) {
    060            theInstance.track(file, marker);
    061        }
    062
    063        /**
    064         * Track the specified file, using the provided marker, deleting the file
    065         * when the marker instance is garbage collected.
    066         * The speified deletion strategy is used.
    067         *
    068         * @param file  the file to be tracked, not null
    069         * @param marker  the marker object used to track the file, not null
    070         * @param deleteStrategy  the strategy to delete the file, null means normal
    071         * @throws NullPointerException if the file is null
    072         * @deprecated Use {@link FileCleaningTracker#track(File, Object, FileDeleteStrategy)}.
    073         */
    074        @Deprecated
    075        public static void track(File file, Object marker, FileDeleteStrategy deleteStrategy) {
    076            theInstance.track(file, marker, deleteStrategy);
    077        }
    078
    079        /**
    080         * Track the specified file, using the provided marker, deleting the file
    081         * when the marker instance is garbage collected.
    082         * The {@link FileDeleteStrategy#NORMAL normal} deletion strategy will be used.
    083         *
    084         * @param path  the full path to the file to be tracked, not null
    085         * @param marker  the marker object used to track the file, not null
    086         * @throws NullPointerException if the path is null
    087         * @deprecated Use {@link FileCleaningTracker#track(String, Object)}.
    088         */
    089        @Deprecated
    090        public static void track(String path, Object marker) {
    091            theInstance.track(path, marker);
    092        }
    093
    094        /**
    095         * Track the specified file, using the provided marker, deleting the file
    096         * when the marker instance is garbage collected.
    097         * The speified deletion strategy is used.
    098         *
    099         * @param path  the full path to the file to be tracked, not null
    100         * @param marker  the marker object used to track the file, not null
    101         * @param deleteStrategy  the strategy to delete the file, null means normal
    102         * @throws NullPointerException if the path is null
    103         * @deprecated Use {@link FileCleaningTracker#track(String, Object, FileDeleteStrategy)}.
    104         */
    105        @Deprecated
    106        public static void track(String path, Object marker, FileDeleteStrategy deleteStrategy) {
    107            theInstance.track(path, marker, deleteStrategy);
    108        }
    109
    110        //-----------------------------------------------------------------------
    111        /**
    112         * Retrieve the number of files currently being tracked, and therefore
    113         * awaiting deletion.
    114         *
    115         * @return the number of files being tracked
    116         * @deprecated Use {@link FileCleaningTracker#getTrackCount()}.
    117         */
    118        @Deprecated
    119        public static int getTrackCount() {
    120            return theInstance.getTrackCount();
    121        }
    122
    123        /**
    124         * Call this method to cause the file cleaner thread to terminate when
    125         * there are no more objects being tracked for deletion.
    126         * <p>
    127         * In a simple environment, you don't need this method as the file cleaner
    128         * thread will simply exit when the JVM exits. In a more complex environment,
    129         * with multiple class loaders (such as an application server), you should be
    130         * aware that the file cleaner thread will continue running even if the class
    131         * loader it was started from terminates. This can consitute a memory leak.
    132         * <p>
    133         * For example, suppose that you have developed a web application, which
    134         * contains the commons-io jar file in your WEB-INF/lib directory. In other
    135         * words, the FileCleaner class is loaded through the class loader of your
    136         * web application. If the web application is terminated, but the servlet
    137         * container is still running, then the file cleaner thread will still exist,
    138         * posing a memory leak.
    139         * <p>
    140         * This method allows the thread to be terminated. Simply call this method
    141         * in the resource cleanup code, such as {@link javax.servlet.ServletContextListener#contextDestroyed}.
    142         * One called, no new objects can be tracked by the file cleaner.
    143         * @deprecated Use {@link FileCleaningTracker#exitWhenFinished()}.
    144         */
    145        @Deprecated
    146        public static synchronized void exitWhenFinished() {
    147            theInstance.exitWhenFinished();
    148        }
    149
    150        /**
    151         * Returns the singleton instance, which is used by the deprecated, static methods.
    152         * This is mainly useful for code, which wants to support the new
    153         * {@link FileCleaningTracker} class while maintain compatibility with the
    154         * deprecated {@link FileCleaner}.
    155         *
    156         * @return the singleton instance
    157         */
    158        public static FileCleaningTracker getInstance() {
    159            return theInstance;
    160        }
    161    }