Spring-batch chained + composite item processor and writer - spring-batch

Question

I have to configure my batch job flows like this.
XML File reader -> Item processor#1 (Process item from the source XML File) -> Item processor#2 (Process item from the processor#1 result) -> Item writer#1 (Write the item from the processor#1) -> Item writer#2 (Write the item from the processor#2)
My custom processor looks like this
public class MyCompositeProcessor implements ItemProcessor<MySource, MyCompositeResult> {
#Override
public MyCompositeResult process(MySource item) throws Exception {
MyResult1 result1 = myProcessor1.process(item);
MyResult2 result2 = myProcessor2.process(result1);
return MyCompositeResult(result1, result2);
}
}
public class MyCompositeWriter implements ItemWriter<MyCompositeResult> {
#Override
public void write(List<? extends MyCompositeResult> items) throws Exception {
myWriter1.write(item.getResult1());
myWriter2.write(item.getResult2());
}
}
Is that a good approach? I saw some examples of CompositeProcessor, CompositeWriter but none of them suitable for my case.
Thanks in advance.

Answer 1

If I understand correctly, your requirement is like the following:
item reader → item processor 1 → item processor 2
↓ ↓
item writer 1 item writer 2
The composite item processor/writer route won't work in your case because it will be like:
item reader → composite item processor → composite item writer
(processor 1 → processor 2) (writer 1 → writer 2)
which is not what you want. You requirement is specific and you would need a custom ChunkProcessor implementation, specifically, a composite chunk processor:
item reader → chunk processor 1 → chunk processor 2
(item processor 1) (item processor 2)
( ↓ ) ( ↓ )
(item writer 1 ) (item writer 2 )