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 * @version $Id: FileCleaner.java 1302056 2012-03-18 03:03:38Z ggregory $
036 * @deprecated Use {@link FileCleaningTracker}
037 */
038 @Deprecated
039 public class FileCleaner {
040 /**
041 * The instance to use for the deprecated, static methods.
042 */
043 static final FileCleaningTracker theInstance = new FileCleaningTracker();
044
045 //-----------------------------------------------------------------------
046 /**
047 * Track the specified file, using the provided marker, deleting the file
048 * when the marker instance is garbage collected.
049 * The {@link FileDeleteStrategy#NORMAL normal} deletion strategy will be used.
050 *
051 * @param file the file to be tracked, not null
052 * @param marker the marker object used to track the file, not null
053 * @throws NullPointerException if the file is null
054 * @deprecated Use {@link FileCleaningTracker#track(File, Object)}.
055 */
056 @Deprecated
057 public static void track(File file, Object marker) {
058 theInstance.track(file, marker);
059 }
060
061 /**
062 * Track the specified file, using the provided marker, deleting the file
063 * when the marker instance is garbage collected.
064 * The speified deletion strategy is used.
065 *
066 * @param file the file to be tracked, not null
067 * @param marker the marker object used to track the file, not null
068 * @param deleteStrategy the strategy to delete the file, null means normal
069 * @throws NullPointerException if the file is null
070 * @deprecated Use {@link FileCleaningTracker#track(File, Object, FileDeleteStrategy)}.
071 */
072 @Deprecated
073 public static void track(File file, Object marker, FileDeleteStrategy deleteStrategy) {
074 theInstance.track(file, marker, deleteStrategy);
075 }
076
077 /**
078 * Track the specified file, using the provided marker, deleting the file
079 * when the marker instance is garbage collected.
080 * The {@link FileDeleteStrategy#NORMAL normal} deletion strategy will be used.
081 *
082 * @param path the full path to the file to be tracked, not null
083 * @param marker the marker object used to track the file, not null
084 * @throws NullPointerException if the path is null
085 * @deprecated Use {@link FileCleaningTracker#track(String, Object)}.
086 */
087 @Deprecated
088 public static void track(String path, Object marker) {
089 theInstance.track(path, marker);
090 }
091
092 /**
093 * Track the specified file, using the provided marker, deleting the file
094 * when the marker instance is garbage collected.
095 * The speified deletion strategy is used.
096 *
097 * @param path the full path to the file to be tracked, not null
098 * @param marker the marker object used to track the file, not null
099 * @param deleteStrategy the strategy to delete the file, null means normal
100 * @throws NullPointerException if the path is null
101 * @deprecated Use {@link FileCleaningTracker#track(String, Object, FileDeleteStrategy)}.
102 */
103 @Deprecated
104 public static void track(String path, Object marker, FileDeleteStrategy deleteStrategy) {
105 theInstance.track(path, marker, deleteStrategy);
106 }
107
108 //-----------------------------------------------------------------------
109 /**
110 * Retrieve the number of files currently being tracked, and therefore
111 * awaiting deletion.
112 *
113 * @return the number of files being tracked
114 * @deprecated Use {@link FileCleaningTracker#getTrackCount()}.
115 */
116 @Deprecated
117 public static int getTrackCount() {
118 return theInstance.getTrackCount();
119 }
120
121 /**
122 * Call this method to cause the file cleaner thread to terminate when
123 * there are no more objects being tracked for deletion.
124 * <p>
125 * In a simple environment, you don't need this method as the file cleaner
126 * thread will simply exit when the JVM exits. In a more complex environment,
127 * with multiple class loaders (such as an application server), you should be
128 * aware that the file cleaner thread will continue running even if the class
129 * loader it was started from terminates. This can consitute a memory leak.
130 * <p>
131 * For example, suppose that you have developed a web application, which
132 * contains the commons-io jar file in your WEB-INF/lib directory. In other
133 * words, the FileCleaner class is loaded through the class loader of your
134 * web application. If the web application is terminated, but the servlet
135 * container is still running, then the file cleaner thread will still exist,
136 * posing a memory leak.
137 * <p>
138 * This method allows the thread to be terminated. Simply call this method
139 * in the resource cleanup code, such as {@link javax.servlet.ServletContextListener#contextDestroyed}.
140 * One called, no new objects can be tracked by the file cleaner.
141 * @deprecated Use {@link FileCleaningTracker#exitWhenFinished()}.
142 */
143 @Deprecated
144 public static synchronized void exitWhenFinished() {
145 theInstance.exitWhenFinished();
146 }
147
148 /**
149 * Returns the singleton instance, which is used by the deprecated, static methods.
150 * This is mainly useful for code, which wants to support the new
151 * {@link FileCleaningTracker} class while maintain compatibility with the
152 * deprecated {@link FileCleaner}.
153 *
154 * @return the singleton instance
155 */
156 public static FileCleaningTracker getInstance() {
157 return theInstance;
158 }
159 }