org.apache.commons.io.FileCleaner Maven / Gradle / Ivy
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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.io;
import java.io.File;
/**
* Keeps track of files awaiting deletion, and deletes them when an associated
* marker object is reclaimed by the garbage collector.
*
* This utility creates a background thread to handle file deletion.
* Each file to be deleted is registered with a handler object.
* When the handler object is garbage collected, the file is deleted.
*
* In an environment with multiple class loaders (a servlet container, for
* example), you should consider stopping the background thread if it is no
* longer needed. This is done by invoking the method
* {@link #exitWhenFinished}, typically in
* {@code javax.servlet.ServletContextListener.contextDestroyed(javax.servlet.ServletContextEvent)} or similar.
*
* @deprecated Use {@link FileCleaningTracker}
*/
@Deprecated
public class FileCleaner {
/**
* The instance to use for the deprecated, static methods.
*/
static final FileCleaningTracker theInstance = new FileCleaningTracker();
//-----------------------------------------------------------------------
/**
* Track the specified file, using the provided marker, deleting the file
* when the marker instance is garbage collected.
* The {@link FileDeleteStrategy#NORMAL normal} deletion strategy will be used.
*
* @param file the file to be tracked, not null
* @param marker the marker object used to track the file, not null
* @throws NullPointerException if the file is null
* @deprecated Use {@link FileCleaningTracker#track(File, Object)}.
*/
@Deprecated
public static void track(final File file, final Object marker) {
theInstance.track(file, marker);
}
/**
* Track the specified file, using the provided marker, deleting the file
* when the marker instance is garbage collected.
* The specified deletion strategy is used.
*
* @param file the file to be tracked, not null
* @param marker the marker object used to track the file, not null
* @param deleteStrategy the strategy to delete the file, null means normal
* @throws NullPointerException if the file is null
* @deprecated Use {@link FileCleaningTracker#track(File, Object, FileDeleteStrategy)}.
*/
@Deprecated
public static void track(final File file, final Object marker, final FileDeleteStrategy deleteStrategy) {
theInstance.track(file, marker, deleteStrategy);
}
/**
* Track the specified file, using the provided marker, deleting the file
* when the marker instance is garbage collected.
* The {@link FileDeleteStrategy#NORMAL normal} deletion strategy will be used.
*
* @param path the full path to the file to be tracked, not null
* @param marker the marker object used to track the file, not null
* @throws NullPointerException if the path is null
* @deprecated Use {@link FileCleaningTracker#track(String, Object)}.
*/
@Deprecated
public static void track(final String path, final Object marker) {
theInstance.track(path, marker);
}
/**
* Track the specified file, using the provided marker, deleting the file
* when the marker instance is garbage collected.
* The specified deletion strategy is used.
*
* @param path the full path to the file to be tracked, not null
* @param marker the marker object used to track the file, not null
* @param deleteStrategy the strategy to delete the file, null means normal
* @throws NullPointerException if the path is null
* @deprecated Use {@link FileCleaningTracker#track(String, Object, FileDeleteStrategy)}.
*/
@Deprecated
public static void track(final String path, final Object marker, final FileDeleteStrategy deleteStrategy) {
theInstance.track(path, marker, deleteStrategy);
}
//-----------------------------------------------------------------------
/**
* Retrieve the number of files currently being tracked, and therefore
* awaiting deletion.
*
* @return the number of files being tracked
* @deprecated Use {@link FileCleaningTracker#getTrackCount()}.
*/
@Deprecated
public static int getTrackCount() {
return theInstance.getTrackCount();
}
/**
* Call this method to cause the file cleaner thread to terminate when
* there are no more objects being tracked for deletion.
*
* In a simple environment, you don't need this method as the file cleaner
* thread will simply exit when the JVM exits. In a more complex environment,
* with multiple class loaders (such as an application server), you should be
* aware that the file cleaner thread will continue running even if the class
* loader it was started from terminates. This can constitute a memory leak.
*
* For example, suppose that you have developed a web application, which
* contains the commons-io jar file in your WEB-INF/lib directory. In other
* words, the FileCleaner class is loaded through the class loader of your
* web application. If the web application is terminated, but the servlet
* container is still running, then the file cleaner thread will still exist,
* posing a memory leak.
*
* This method allows the thread to be terminated. Simply call this method
* in the resource cleanup code, such as
* {@code javax.servlet.ServletContextListener.contextDestroyed(javax.servlet.ServletContextEvent)}.
* One called, no new objects can be tracked by the file cleaner.
* @deprecated Use {@link FileCleaningTracker#exitWhenFinished()}.
*/
@Deprecated
public static synchronized void exitWhenFinished() {
theInstance.exitWhenFinished();
}
/**
* Returns the singleton instance, which is used by the deprecated, static methods.
* This is mainly useful for code, which wants to support the new
* {@link FileCleaningTracker} class while maintain compatibility with the
* deprecated {@link FileCleaner}.
*
* @return the singleton instance
*/
public static FileCleaningTracker getInstance() {
return theInstance;
}
}