public interface WindowableTask
StreamTask implementations to add code which will be run on
 a specified time interval (via configuration).  This can be used to implement direct time-based windowing or,
 with a frequent window interval, windowing based on some other condition which is checked during the call to
 window.  The window method will be called even if no messages are received for a particular StreamTask.| Modifier and Type | Method and Description | 
|---|---|
| void | window(MessageCollector collector,
      TaskCoordinator coordinator)Called by TaskRunner for each implementing task at the end of every specified window. | 
void window(MessageCollector collector, TaskCoordinator coordinator) throws java.lang.Exception
collector - Contains the means of sending message envelopes to the output stream. The collector must only
 be used during the current call to the window method; you should not reuse the collector between invocations
 of this method.coordinator - Manages execution of tasks.java.lang.Exception - Any exception types encountered during the execution of the processing task.