Throw an exception when the BatchWriter fails on a write operation

[sastafford]

As a developer
I want to TITLE
So that I can handle the exception appropriately and continue to write the next batch.

I have ran into a Batch error where I have a conflicting update error (the batch of documents have two docs with the same URI). Unfortunately it causes the whole program to crash. I would like to take note and log the error but I would like the program to continue.

I believe it is just adding a throws statement on the BatchWriter.write() method.

[sastafford]

Looking into this a bit more, one option would be to create a try/catch in RestBatchWriter. I'm approaching this from MarkLogicItemWriter using this service. Who should handle the exception?

[rjrudin]

I think a Listener interface is appropriate here. I thought that ThreadPoolTaskExecutor had such a thing - it does, but it requires attaching a FailureCallback to the ListenableFuture that's returned. Since subclasses of BatchWriterSupport aren't guaranteed to be doing async writes, I think a listener interface is appropriate here.

[rjrudin]

@sastafford How does this look?

b0d59cf

I don't think anything is needed when a non-async TaskExecutor is used, as the client can just use a try/catch itself.