1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.io; 18 19 import java.io.File; 20 21 /** 22 * Keeps track of files awaiting deletion, and deletes them when an associated 23 * marker object is reclaimed by the garbage collector. 24 * <p> 25 * This utility creates a background thread to handle file deletion. 26 * Each file to be deleted is registered with a handler object. 27 * When the handler object is garbage collected, the file is deleted. 28 * <p> 29 * In an environment with multiple class loaders (a servlet container, for 30 * example), you should consider stopping the background thread if it is no 31 * longer needed. This is done by invoking the method 32 * {@link #exitWhenFinished}, typically in 33 * {@link javax.servlet.ServletContextListener#contextDestroyed} or similar. 34 * 35 * @author Noel Bergman 36 * @author Martin Cooper 37 * @version $Id: FileCleaner.java 553012 2007-07-03 23:01:07Z ggregory $ 38 * @deprecated Use {@link FileCleaningTracker} 39 */ 40 public class FileCleaner { 41 /** 42 * The instance to use for the deprecated, static methods. 43 */ 44 static final FileCleaningTracker theInstance = new FileCleaningTracker(); 45 46 //----------------------------------------------------------------------- 47 /** 48 * Track the specified file, using the provided marker, deleting the file 49 * when the marker instance is garbage collected. 50 * The {@link FileDeleteStrategy#NORMAL normal} deletion strategy will be used. 51 * 52 * @param file the file to be tracked, not null 53 * @param marker the marker object used to track the file, not null 54 * @throws NullPointerException if the file is null 55 * @deprecated Use {@link FileCleaningTracker#track(File, Object)}. 56 */ 57 public static void track(File file, Object marker) { 58 theInstance.track(file, marker); 59 } 60 61 /** 62 * Track the specified file, using the provided marker, deleting the file 63 * when the marker instance is garbage collected. 64 * The speified deletion strategy is used. 65 * 66 * @param file the file to be tracked, not null 67 * @param marker the marker object used to track the file, not null 68 * @param deleteStrategy the strategy to delete the file, null means normal 69 * @throws NullPointerException if the file is null 70 * @deprecated Use {@link FileCleaningTracker#track(File, Object, FileDeleteStrategy)}. 71 */ 72 public static void track(File file, Object marker, FileDeleteStrategy deleteStrategy) { 73 theInstance.track(file, marker, deleteStrategy); 74 } 75 76 /** 77 * Track the specified file, using the provided marker, deleting the file 78 * when the marker instance is garbage collected. 79 * The {@link FileDeleteStrategy#NORMAL normal} deletion strategy will be used. 80 * 81 * @param path the full path to the file to be tracked, not null 82 * @param marker the marker object used to track the file, not null 83 * @throws NullPointerException if the path is null 84 * @deprecated Use {@link FileCleaningTracker#track(String, Object)}. 85 */ 86 public static void track(String path, Object marker) { 87 theInstance.track(path, marker); 88 } 89 90 /** 91 * Track the specified file, using the provided marker, deleting the file 92 * when the marker instance is garbage collected. 93 * The speified deletion strategy is used. 94 * 95 * @param path the full path to the file to be tracked, not null 96 * @param marker the marker object used to track the file, not null 97 * @param deleteStrategy the strategy to delete the file, null means normal 98 * @throws NullPointerException if the path is null 99 * @deprecated Use {@link FileCleaningTracker#track(String, Object, FileDeleteStrategy)}. 100 */ 101 public static void track(String path, Object marker, FileDeleteStrategy deleteStrategy) { 102 theInstance.track(path, marker, deleteStrategy); 103 } 104 105 //----------------------------------------------------------------------- 106 /** 107 * Retrieve the number of files currently being tracked, and therefore 108 * awaiting deletion. 109 * 110 * @return the number of files being tracked 111 * @deprecated Use {@link FileCleaningTracker#getTrackCount()}. 112 */ 113 public static int getTrackCount() { 114 return theInstance.getTrackCount(); 115 } 116 117 /** 118 * Call this method to cause the file cleaner thread to terminate when 119 * there are no more objects being tracked for deletion. 120 * <p> 121 * In a simple environment, you don't need this method as the file cleaner 122 * thread will simply exit when the JVM exits. In a more complex environment, 123 * with multiple class loaders (such as an application server), you should be 124 * aware that the file cleaner thread will continue running even if the class 125 * loader it was started from terminates. This can consitute a memory leak. 126 * <p> 127 * For example, suppose that you have developed a web application, which 128 * contains the commons-io jar file in your WEB-INF/lib directory. In other 129 * words, the FileCleaner class is loaded through the class loader of your 130 * web application. If the web application is terminated, but the servlet 131 * container is still running, then the file cleaner thread will still exist, 132 * posing a memory leak. 133 * <p> 134 * This method allows the thread to be terminated. Simply call this method 135 * in the resource cleanup code, such as {@link javax.servlet.ServletContextListener#contextDestroyed}. 136 * One called, no new objects can be tracked by the file cleaner. 137 * @deprecated Use {@link FileCleaningTracker#exitWhenFinished()}. 138 */ 139 public static synchronized void exitWhenFinished() { 140 theInstance.exitWhenFinished(); 141 } 142 143 /** 144 * Returns the singleton instance, which is used by the deprecated, static methods. 145 * This is mainly useful for code, which wants to support the new 146 * {@link FileCleaningTracker} class while maintain compatibility with the 147 * deprecated {@link FileCleaner}. 148 * 149 * @return the singleton instance 150 */ 151 public static FileCleaningTracker getInstance() { 152 return theInstance; 153 } 154 } 155
