Call the listeners close method when stopJob is called.

[vivekmuniyandi]

It is the responsibility of the QueryBatcher and the WriteBatcher to call any close() methods of the listeners registered with them. If the listeners had to close any resources, they can implement AutoCloseable interface and close the resources in the close() method. QueryBatcher and WriteBatcher would iterate all the listeners and call any close() methods when stopJob is called on the batcher.

Similarly, it is the responsibility of the listeners to close any resources opened by the consumers registered with them. It should implement AutoCloseable and iterate all the Consumers and call close() methods as necessary. This should be done in the close() method of the listener which would be closed by the Batcher when stopJob is called.

Batcher(QueryBatcher/WriteBatcher) -> calls the listeners' close method (which are registered with the Batcher)
Listeners -> calls the Consumers close() method (which are registered with the listeners)

[vivekmuniyandi]

For QA

Added private method closeAllListeners to both WriteBatcher and QueryBatcher which would close all the listeners (both success and failure listeners) if they are instances of AutoCloseable by calling the close() method of the listeners. This is done when stopJob() is called on the Batcher.

For Docs

We take care of calling the close() method of the listeners which are registered with the Batcher.

Batcher(QueryBatcher/WriteBatcher) -> calls the listeners' close method in stopJob() method (which are registered with the Batcher)

Although the following needs to be implemented at the listener level, it is our responsibility to convey the customers that they have to call the Consumers' close() method. For example: See ExtractViaTemplateListener.java close() method (It is in a feature branch issue839 for now which will eventually get into develop branch before 4.0.4)

Listeners -> calls the Consumers close() method (which are registered with the listeners)