Package name.pachler.nio.file
Class WatchKey
java.lang.Object
name.pachler.nio.file.WatchKey
- Direct Known Subclasses:
PathWatchKey
A
To stop receiving events from a
WatchKey
represents a Watchable
's registration for events with a
WatchService
. It is created on registration and subsequently used to retreive
WatchEvent
s.To stop receiving events from a
WatchService
(that is, undoing registration),
use the cancel()
method. Note that this will invalidate the WatchKey
, which
should then be discarded (as it cannot be reused).-
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionabstract void
cancel()
This cancels the registration with the WatchService that this WatchKey was registered with.abstract boolean
isValid()
abstract List<WatchEvent<?>>
Returns the events that have occurred for this WatchKey.abstract boolean
reset()
Resets thisWatchKey
(marks it as non-signalled) so that it's correspondingWatchService
can report it again via it'sWatchService.poll()
andWatchService.take()
methods.
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Constructor Details
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WatchKey
protected WatchKey()
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Method Details
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cancel
public abstract void cancel()This cancels the registration with the WatchService that this WatchKey was registered with. This means that no new events will be delivered to this key any more. Events that are pending can still be retreived with pollEvents(), and if the WatchKey is still marked as signalled a call to WatchService's poll() or take() functions will still return it. -
isValid
public abstract boolean isValid()- Returns:
- if this watch key is valid. A watch key is valid if
- It has not been canceled
- The WatchService is not yet closed
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pollEvents
Returns the events that have occurred for this WatchKey. Just calling this method will not reset the signalled state of this key; you'll have to call #reset() to indicate to the WatchService that the the client is ready to receive more events and that the key can be re-queued. After the WatchService has determined that events have occurred for a registered Watchable represented by a given WatchKey, it will return that key when the client calls it's WatchService#take() or WatchService#poll() methods.- Returns:
- a list of events that have occurred since the last time that #pollEvents() was called.
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reset
public abstract boolean reset()Resets thisWatchKey
(marks it as non-signalled) so that it's correspondingWatchService
can report it again via it'sWatchService.poll()
andWatchService.take()
methods.- Returns:
true
if the key could be reset,false
otherwise (typically if the correspondingWatchService
has been closed or if the the key was not signalled).
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