Module java.base
Package java.nio.file

Interface WatchEvent<T>

Type Parameters:
T - The type of the context object associated with the event
public interface WatchEvent<T>
An event or a repeated event for an object that is registered with a WatchService.

An event is classified by its kind and has a count to indicate the number of times that the event has been observed. This allows for efficient representation of repeated events. The context method returns any context associated with the event. In the case of a repeated event then the context is the same for all events.

Watch events are immutable and safe for use by multiple concurrent threads.

Since:
1.7

  • Nested Class Summary

    Nested Classes 
    Modifier and Type Interface Description
    static interface  WatchEvent.Kind<T>
    An event kind, for the purposes of identification.
    static interface  WatchEvent.Modifier
    An event modifier that qualifies how a Watchable is registered with a WatchService.

  • Method Summary

    Modifier and Type Method Description
    T context()
    Returns the context for the event.
    int count()
    Returns the event count.
    WatchEvent.Kind<T> kind()
    Returns the event kind.

  • Method Details

    • kind

      WatchEvent.Kind<T> kind()
      Returns the event kind.
      Returns:
      the event kind

    • count

      int count()
      Returns the event count. If the event count is greater than 1 then this is a repeated event.
      Returns:
      the event count

    • context

      T context()
      Returns the context for the event.

      In the case of ENTRY_CREATE, ENTRY_DELETE, and ENTRY_MODIFY events the context is a Path that is the relative path between the directory registered with the watch service, and the entry that is created, deleted, or modified.

      Returns:
      the event context; may be null