Class AbstractWatchService

java.lang.Object

com.google.common.jimfs.AbstractWatchService

All Implemented Interfaces:

Closeable, AutoCloseable, WatchService

Direct Known Subclasses:

PollingWatchService

abstract class AbstractWatchService
extends Object
implements WatchService

Abstract implementation of WatchService. Provides the means for registering and managing keys but does not handle actually watching. Subclasses should implement the means of watching watchables, posting events to registered keys and queueing keys with the service by signalling them.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static final class	AbstractWatchService.Event<T>	A basic implementation of WatchEvent.
(package private) static final class	AbstractWatchService.Key	Implementation of WatchKey for an AbstractWatchService.

Field Summary

Fields

Modifier and Type	Field	Description
private final AtomicBoolean	open
private final WatchKey	poison
private final BlockingQueue<WatchKey>	queue

Constructor Summary

Constructors

Constructor	Description
AbstractWatchService()

Method Summary

Modifier and Type	Method	Description
void	cancelled(AbstractWatchService.Key key)	Called when the given key is cancelled.
private @Nullable WatchKey	check(@Nullable WatchKey key)	Returns the given key, throwing an exception if it's the poison.
protected final void	checkOpen()	Checks that the watch service is open, throwing ClosedWatchServiceException if not.
void	close()
(package private) final void	enqueue(AbstractWatchService.Key key)	Enqueues the given key if the watch service is open; does nothing otherwise.
boolean	isOpen()	Returns whether or not this watch service is open.
@Nullable WatchKey	poll()
@Nullable WatchKey	poll(long timeout, TimeUnit unit)
(package private) com.google.common.collect.ImmutableList<WatchKey>	queuedKeys()
AbstractWatchService.Key	register(Watchable watchable, Iterable<? extends WatchEvent.Kind<?>> eventTypes)	Registers the given watchable with this service, returning a new watch key for it.
WatchKey	take()

Methods inherited from class Object

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

Field Details

queue

private final BlockingQueue<WatchKey> queue

poison

private final WatchKey poison

open

private final AtomicBoolean open

Constructor Details

AbstractWatchService

AbstractWatchService()

Method Details

register

public AbstractWatchService.Key register(Watchable watchable,
 Iterable<? extends WatchEvent.Kind<?>> eventTypes)
                                  throws IOException

Registers the given watchable with this service, returning a new watch key for it. This implementation just checks that the service is open and creates a key; subclasses may override it to do other things as well.

Throws:

IOException

isOpen

public boolean isOpen()

Returns whether or not this watch service is open.

enqueue

final void enqueue(AbstractWatchService.Key key)

Enqueues the given key if the watch service is open; does nothing otherwise.

cancelled

public void cancelled(AbstractWatchService.Key key)

Called when the given key is cancelled. Does nothing by default.

queuedKeys

com.google.common.collect.ImmutableList<WatchKey> queuedKeys()

poll

public @Nullable WatchKey poll()

Specified by:

poll in interface WatchService

poll

public @Nullable WatchKey poll(long timeout,
 TimeUnit unit)
                        throws InterruptedException

Specified by:

poll in interface WatchService

Throws:

InterruptedException

take

public WatchKey take()
              throws InterruptedException

Specified by:

take in interface WatchService

Throws:

InterruptedException

check

private @Nullable WatchKey check(@Nullable WatchKey key)

Returns the given key, throwing an exception if it's the poison.

checkOpen

protected final void checkOpen()

Checks that the watch service is open, throwing ClosedWatchServiceException if not.

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface WatchService