com.tibco.as.space.browser

Interface EventBrowser

public interface EventBrowser

An EventBrowser is used to iterate through the events which occur for the entries in a Space (e.g. put, take, expire) as opposed to a Browser which is used to iterate through the entries of a Space. An EventBrowser is created by calling Metaspace.browseEvents(java.lang.String, com.tibco.as.space.browser.EventBrowserDef). EventBrowsers implement a next() and a stop() method but unlike traditional iterators, an EventBrowser does not have a hasNext() method. Instead EventBrowsers have a timeout which is the amount of time that the next() method call will block while waiting for a new event to occur in the Space. EventBrowsers have several mechanisms which help to limit the events being browsed. The time scope setting limits the set of events being iterated over based upon the time the entries, for which the events occur, are stored in the space relative to the time the EventBrowser is created.

• Time scope ALL means that events for all of the entries stored in the Space at the time the EventBrowser is created will be browsed, followed by all subsequent events which occur in the Space.
• Time scope NEW means that only events pertaining to the entries stored in the Space after the EventBrowser creation time, will be browsed.
• Time scope NEW_EVENTS means that all events which occur in the Space after the EventBrowser is created will be browsed, regardless of the creation time of the entry associated with an event.
• Time scope SNAPSHOT means that only the events which occur for entries stored in the Space at the time the EventBrowser is created will be browsed.

The distribution scope setting limits the set of events being iterated over based upon where the entries, for which the events occur, are stored in the space.

• Distribution scope ALL means that events for all of the entries in the Space will be browsed.
• Distribution scope SEEDED means that only the events which occur for entries stored by the invoking member will be browsed.

An optional filter can be applied to EventBrowsers to further refine the set of events being iterated over. EventBrowsers do not guarantee any order of presentation of the events related to entries already present in the Space at the time the EventBrowser is created.

See Also:

EventBrowserDef, SpaceEvent, Browser

Method Summary

Modifier and Type	Method and Description
SpaceEvent	next() Retrieve the next event of the Space.
void	stop() Stop the EventBrowser.

Method Detail

next

SpaceEvent next()
         throws ASException

Retrieve the next event of the Space.

Returns:

The next event of the Space. null if the EventBrowser times out waiting for an event to occur in the Space.

Throws:

ASException - An exception is thrown if an error occurs while fetching the next event.

stop

void stop()
   throws ASException

Stop the EventBrowser.

Throws:

ASException - An exception is thrown if an error occurs while trying to stop the EventBrowser.