Spring Batch - use JpaPagingItemReader to read lists instead of individual items

Daniel Pop 0
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Spring Batch is designed to read and process one item at a time, then write the list of all items processed in a chunk. I want my item to be a List<T> as well, to be thus read and processed, and then write a List<List<T>>. My data source is a standard Spring JpaRepository<T, ID>.

My question is whether there are some standard solutions for this "aggregated" approach. I see that there are some, but they don't read from a JpaRepository, like:

Update:

I'm looking for a solution that would work for a rapidly changing dataset and in a multithreading environment.

batch-processing spring-data-jpa jpa spring-batch spring
1 Answers

I want my item to be a List as well, to be thus read and processed, and then write a List<List>.

Spring Batch does not (and should not) be aware of what an "item" is. It is up to you do design what an "item" is and how it is implemented (a single value, a list, a stream , etc). In your case, you can encapsulate the List<T> in a type that could be used as an item, and process data as needed. You would need a custom item reader though.

Mahmoud Ben Hassine0
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