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Top Description Methods
java.nio.file

public Interface Watchable

Known Direct Subinterfaces
java.nio.file.Path
Imports
java.io.IOException
An object that may be registered with a watch service so that it can be watched for changes and events.

This interface defines the register method to register the object with a WatchService returning a WatchKey to represent the registration. An object may be registered with more than one watch service. Registration with a watch service is cancelled by invoking the key's cancel method.

Since
1.7
See Also
Path#register

Method Summary

Modifier and TypeMethod and Description
public WatchKey

Returns:

a key representing the registration of this object with the given watch service
register(WatchService
the watch service to which this object is to be registered
watcher, WatchEvent.Kind<?>[]
the events for which this object should be registered
events, WatchEvent.Modifier...
the modifiers, if any, that modify how the object is registered
modifiers)

Registers an object with a watch service.

public WatchKey

Returns:

a key representing the registration of this object with the given watch service
register(WatchService
the watch service to which this object is to be registered
watcher, WatchEvent.Kind<?>...
the events for which this object should be registered
events)

Registers an object with a watch service.

Method Detail

registerback to summary
public WatchKey register(WatchService watcher, WatchEvent.Kind<?>[] events, WatchEvent.Modifier... modifiers) throws IOException

Registers an object with a watch service.

If the file system object identified by this object is currently registered with the watch service then the watch key, representing that registration, is returned after changing the event set or modifiers to those specified by the events and modifiers parameters. Changing the event set does not cause pending events for the object to be discarded. Objects are automatically registered for the OVERFLOW event. This event is not required to be present in the array of events.

Otherwise the file system object has not yet been registered with the given watch service, so it is registered and the resulting new key is returned.

Implementations of this interface should specify the events they support.

Parameters
watcher:WatchService

the watch service to which this object is to be registered

events:WatchEvent.Kind<?>[]

the events for which this object should be registered

modifiers:WatchEvent.Modifier[]

the modifiers, if any, that modify how the object is registered

Returns:WatchKey

a key representing the registration of this object with the given watch service

Exceptions
IOException:
if an I/O error occurs
UnsupportedOperationException:
if unsupported events or modifiers are specified
IllegalArgumentException:
if an invalid of combination of events are modifiers are specified
ClosedWatchServiceException:
if the watch service is closed
registerback to summary
public WatchKey register(WatchService watcher, WatchEvent.Kind<?>... events) throws IOException

Registers an object with a watch service.

An invocation of this method behaves in exactly the same way as the invocation

register.watcher, events, new WatchEvent.Modifier[0]); 
register.watcher, events, new WatchEvent.Modifier[0]);
Parameters
watcher:WatchService

the watch service to which this object is to be registered

events:WatchEvent.Kind<?>[]

the events for which this object should be registered

Returns:WatchKey

a key representing the registration of this object with the given watch service

Exceptions
IOException:
if an I/O error occurs
UnsupportedOperationException:
if unsupported events are specified
IllegalArgumentException:
if an invalid of combination of events are specified
ClosedWatchServiceException:
if the watch service is closed