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 }