Package com.helger.commons.io.watchdir

Class WatchDir

java.lang.Object

com.helger.commons.io.watchdir.WatchDir

All Implemented Interfaces:

AutoCloseable

public class WatchDir
extends Object
implements AutoCloseable

Generic directory watching service using the default JDK WatchService class.

Since:

9.0.0

Author:

Philip Helger

Constructor Summary

Constructors

Constructor	Description
WatchDir(Path aDir, boolean bRecursive)	Creates a WatchService and registers the given directory

Method Summary

Modifier and Type	Method	Description
CallbackList<IWatchDirCallback>	callbacks()
void	close()	Close the watch directory service and stop processing.
static WatchDir	createAsyncRunningWatchDir(Path aDir, boolean bRecursive, IWatchDirCallback aCallback)	Static factory method to create a simple WatchDir instance that already spawned an Thread to listen.
Path	getStartDirectory()
boolean	isProcessing()	Check if processing is active.
boolean	isRecursive()
void	processEvents()	Process all events for keys queued to the watcher.
void	runAsync()	Call this method to process events.
Thread	runAsyncAndReturn()	Call this method to process events.
void	stopProcessing()	Stop processing, if processEvents() is active.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

WatchDir

public WatchDir(@Nonnull
                Path aDir,
                boolean bRecursive)
         throws IOException

Creates a WatchService and registers the given directory

Parameters:

aDir - The directory to be watched. May not be null.

bRecursive - true to watch the directory recursive, false to watch just this directory.

Throws:

IOException - In case something goes wrong.

Method Detail

callbacks

@Nonnull
@ReturnsMutableObject
public CallbackList<IWatchDirCallback> callbacks()

Returns:

The modifiable callback list. Never null.

getStartDirectory

@Nonnull
public Path getStartDirectory()

Returns:

The start directory as specified in the constructor. Never null.

isRecursive

public boolean isRecursive()

Returns:

true if this is a recursive listener, false if not.

close

public void close()
           throws IOException

Close the watch directory service and stop processing.

Specified by:

close in interface AutoCloseable

Throws:

IOException

stopProcessing

public void stopProcessing()

Stop processing, if processEvents() is active. This method is automatically called in close().

isProcessing

public boolean isProcessing()

Check if processing is active.

Returns:

true if event processing is active, false if not.

See Also:

processEvents(), stopProcessing(), close()

processEvents

public void processEvents()

Process all events for keys queued to the watcher. Call stopProcessing() or close() to stop processing within a reasonable time. This method should run in a separate thread, as it contains an infinite loop! Usually you don't call this method manually.

See Also:

runAsync()

runAsync

public void runAsync()

Call this method to process events. This method creates a background thread than runs processEvents() and performs the heavy lifting.

runAsyncAndReturn

@Nonnull
public Thread runAsyncAndReturn()

Call this method to process events. This method creates a background thread than runs processEvents() and performs the heavy lifting.

Returns:

The created Thread that can also be stopped again if not needed anymore.

Since:

10.1.5

createAsyncRunningWatchDir

@Nonnull
@ReturnsMutableCopy
public static WatchDir createAsyncRunningWatchDir(@Nonnull
                                                  Path aDir,
                                                  boolean bRecursive,
                                                  @Nonnull
                                                  IWatchDirCallback aCallback)
                                           throws IOException

Static factory method to create a simple WatchDir instance that already spawned an Thread to listen. To close the thread call the close() method.

Parameters:

aDir - The directory to be watched. May not be null.

bRecursive - true to watch the directory recursive, false to watch just this directory.

aCallback - The callback to be invoked if something changed. May not be null.

Returns:

The newly created WatchDir instance and never null.

Throws:

IOException - In case something goes wrong.