Spting Batch MultiResourceItemReader with non-FlatFileItemReader - spring-batch

Question

Current flow:
1.BatchItemReader implements ItemReader<List<SingleJsonRowInput>>
2.BatchItemProcessor implements ItemProcessor<List<SingleJsonRowInput>>
3.BatchItemWriter implements ItemWriter<List<String>>
The input is a text file with each row represent a Json file. currently the program runs well with a single file, i would like to implement MultiResourceItemReader but since my reader doesn't imlement this ResourceAwareItemReaderItemStream - it cannot be applied to MultiResourceItemReader. i tried:
1. Implementing ResourceAwareItemReaderItemStream
2. Changing my reader to be FlatFileItemReader as advised here:
Spring Batch: How to setup a FlatFileItemReader to read a json file?
but failed to do so.
Reader:
public class BatchItemReader implements ItemReader<List<SingleJsonRowInput>>{
private int count = 0;
private FileManager fileManager;
private Gson gson = new Gson();
public List<SingleJsonRowInput> read() {
return readLine();
}
public BatchItemReader(FileManager fileManager) {
this.fileManager = fileManager;
}
private List<SingleJsonRowInput> readLine() {
List<String> result = fileManager.readTextJsonFile("C:\\Users\\orenl\\Desktop\\small.json");
List<SingleJsonRowInput> singles = new LinkedList<>();
SingleJsonRowInput singleJsonRowInput = null;
for (String line : result) {
System.out.println("#### Reading line: " + line);
singleJsonRowInput = gson.fromJson(line, SingleJsonRowInput.class);
singles.add(singleJsonRowInput);
}
if (count > 5) {
return null;
}
count++;
return singles;
}
}
MultiResourceItemReader:
#Bean
public MultiResourceItemReader<SingleJsonRowInput> multiResourceItemReader(){
Resource resources[]=new Resource[]{new FileSystemResource("small.json")};
MultiResourceItemReader<SingleJsonRowInput> multiResourceItemReader=new MultiResourceItemReader<>();
multiResourceItemReader.setResources(resources);
multiResourceItemReader.setDelegate(new FlatFileItemReader<>());
return multiResourceItemReader;
}