I have a batch job I’m working on. I have my proce...

# spring

[Michael]

I have a batch job I’m working on. I have my processor returning a Pair, and a CompositeItemWriter that sends half the pair to each of two individual writers. But if something goes wrong, I only want to write to one: normally you can return null from a processor and nothing gets written, but if I return Pair(object1, null), then the writer that receives the null gives me a Target object must not be null. Am I approaching this the wrong way, or is there a way around this?

[poohbar]

I am not sure you can solve this

[Michael]

Batch is an endless struggle to me as I try to find some way to crowbar whatever I need to happen into its [unintuitive-to-me] requirements.

[poohbar]

I built a huge system in Spring Batch so I feel your pain.. I use java config for everything and keep finding documentation for XML setup

[poohbar]

I don't even need to use the automatic recovery and restarts so if I could start all over I would stay far away from Spring Batch.. Too complex for little benefit

[Michael]

I’ve experienced the same (all google results are in xml.) I’m getting better at intuiting my way past some rough parts, but then things like this. sigh.

[poohbar]

null has a special meaning for batch because it's a mark of end of input.. so you can't easily "skip" the null because then it won't know when to finish

[poohbar]

you could solve it by sending some sort of blank value ("null object") which your writer will have a special check for

[Michael]

I’m going to try returning a ClassifierCompositeItemWriter, and based on if the send thing is null, either return the CompositeWriter or the single Writer.

[tmg]

The version of Spring Batch that got released this year changed the docs to have a toggle between java and xml .

[tmg]

The Docs are much better now.