Spring Batch with ItemReader for WebService data input (Chunk Approach) - soap

Question

I have created a simple Spring Batch and I have a Chunk implemented as follows:
public class ChunksConfig {
.......
.......
#Override
protected ItemWriter<List<Pratica>> getItemWriter() {
return praticaWriter;
}
#Override
protected ItemReader<List<GaranziaRichiesta>> getItemReader() {
return praticheReader;
}
#Override
protected ItemProcessor<List<GaranziaRichiesta>, List<Pratica>> getItemProcessor() {
return praticaProcessor;
}
}
Now my reader should retrieve data from SOAP WebServices and, each call, retrieve 100 elements. I try to implement my reader as follows:
#Component
public class PraticaReader implements ItemReader<List<GaranziaRichiesta>> {
#Autowired
SOAPServices soapServices;
#Override
public List<GaranziaRichiesta> read()
throws Exception, UnexpectedInputException, ParseException, NonTransientResourceException {
GaranzieRichiesteRequest request = new GaranzieRichiesteRequest();
GaranzieRichiesteResponse response = soapServices.garanzieRichieste(request);
return response.getGaranzie(); // this contains exactly 100 elements
}
}
Now the problem is that I don't know how set chunk size and how let Spring understand how many element is eleaborating after reading operation.
In fact if I put chunk size to 1 the code flow passes to reader -> processor and writer correctly (but the job doesn't stop and after perform the writer operation starts reading again..). Instead if I put the chunk size to 100, the flow perform 100 reading action before arriving to processor.
I absolutely new to SpringBatch, I read the doc but 90% percent of example is about reading data from file. Can you suggest me if I can do a compliant implementation of Chunk on this particular case or I should try another way?
Thank you