com.espertech.esper.client

Interface UpdateListener

All Known Implementing Classes:

SupportUpdateListener

public interface UpdateListener

Defines an interface to notify of new and old events.

Also see StatementAwareUpdateListener for update listeners that require the statement and service provider instance to be passed to the listener in addition to events.

Method Summary

Modifier and Type	Method and Description
void	update(EventBean[] newEvents, EventBean[] oldEvents) Notify that new events are available or old events are removed.

Method Detail

update

void update(EventBean[] newEvents,
            EventBean[] oldEvents)

Notify that new events are available or old events are removed. If the call to update contains new (inserted) events, then the first argument will be a non-empty list and the second will be empty. Similarly, if the call is a notification of deleted events, then the first argument will be empty and the second will be non-empty.

Either the newEvents or oldEvents will be non-null. This method won't be called with both arguments being null (unless using output rate limiting or force-output options), but either one could be null. The same is true for zero-length arrays. Either newEvents or oldEvents will be non-empty. If both are non-empty, then the update is a modification notification.

Parameters:

newEvents - is any new events. This will be null or empty if the update is for old events only.

oldEvents - is any old events. This will be null or empty if the update is for new events only.