How does the JdbcBatchItemWriter decide the batch size?

I was going through the documentation of the JdbcBatchItemWriter but noticed that there is no way of specifying the batch-size to use for the jdbcTemplate used by this class. I thought a class that has the name Batch in it would have some mechanism to specify the batch size but looks like this is not the case. I now have the following questions regarding determination of batch-size :

1. Is the batch-size equivalent to the commit-interval?
2. If no, does the batch-size get calculated automatically by the framework?

Last but not the least,, is there a way to explicitly specify the batch-size to be used by the jdbcTemplate in the JdbcBatchItemWriter while defining the bean for the JdbcBatchItemWriter class?

The commit (or batch size) will include all items in the chunk, which is governed by the commit-interval. So for all intents and purposes you can treat commit-interval as batch-size.

One caveat to the statement above: your final chunk may have less items than your commit-interval. Additionally if you filter any records using an ItemProcessor, the count of items passed to your Writer would be lower than your commit-interval. Finally, there are also some custom CompletionPolicy scenarios that may result in a commit with more (or less) items than your commit-interval.

Hope that helps!