org.apache.commons.io
public class FileCleaner extends Object
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 {@link javax.servlet.ServletContextListener#contextDestroyed} or similar.
Version: $Id: FileCleaner.java 551002 2007-06-27 01:33:05Z jochen $
Field Summary | |
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static FileCleaningTracker | theInstance
The instance to use for the deprecated, static methods. |
Method Summary | |
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static void | exitWhenFinished()
Call this method to cause the file cleaner thread to terminate when
there are no more objects being tracked for deletion.
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static FileCleaningTracker | getInstance()
Returns the singleton instance, which is used by the deprecated, static methods.
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static int | getTrackCount()
Retrieve the number of files currently being tracked, and therefore
awaiting deletion.
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static void | track(File file, Object marker)
Track the specified file, using the provided marker, deleting the file
when the marker instance is garbage collected.
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static void | track(File file, Object marker, FileDeleteStrategy deleteStrategy)
Track the specified file, using the provided marker, deleting the file
when the marker instance is garbage collected.
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static void | track(String path, Object marker)
Track the specified file, using the provided marker, deleting the file
when the marker instance is garbage collected.
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static void | track(String path, Object marker, FileDeleteStrategy deleteStrategy)
Track the specified file, using the provided marker, deleting the file
when the marker instance is garbage collected.
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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 consitute 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 {@link javax.servlet.ServletContextListener#contextDestroyed}. One called, no new objects can be tracked by the file cleaner.
Returns: the number of files being tracked
Parameters: file the file to be tracked, not null marker the marker object used to track the file, not null
Throws: NullPointerException if the file is null
Parameters: file the file to be tracked, not null marker the marker object used to track the file, not null deleteStrategy the strategy to delete the file, null means normal
Throws: NullPointerException if the file is null
Parameters: path the full path to the file to be tracked, not null marker the marker object used to track the file, not null
Throws: NullPointerException if the path is null
Parameters: path the full path to the file to be tracked, not null marker the marker object used to track the file, not null deleteStrategy the strategy to delete the file, null means normal
Throws: NullPointerException if the path is null