Module java.base
Package java.nio.file

Interface Watchable

    • Method Detail

      • register

        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 - the watch service to which this object is to be registered
        events - the events for which this object should be registered
        modifiers - the modifiers, if any, that modify how the object is registered
        Returns:
        a key representing the registration of this object with the given watch service
        Throws:
        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
        IOException - if an I/O error occurs
        SecurityException - if a security manager is installed and it denies an unspecified permission required to monitor this object. Implementations of this interface should specify the permission checks.
      • register

        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

             watchable.register(watcher, events, new WatchEvent.Modifier[0]);
         
        Parameters:
        watcher - the watch service to which this object is to be registered
        events - the events for which this object should be registered
        Returns:
        a key representing the registration of this object with the given watch service
        Throws:
        UnsupportedOperationException - if unsupported events are specified
        IllegalArgumentException - if an invalid of combination of events are specified
        ClosedWatchServiceException - if the watch service is closed
        IOException - if an I/O error occurs
        SecurityException - if a security manager is installed and it denies an unspecified permission required to monitor this object. Implementations of this interface should specify the permission checks.