# Package org.springframework.batch.sample.support

- Class Summary
  Class | Description
  --- | ---
  DummyItemWriter |
  ExceptionThrowingItemReaderProxy<T> | Hacked `ItemReader` that throws exception on a given record number (useful for testing restart).
  HeaderCopyCallback | Designed to be registered with both `FlatFileItemReader` and `FlatFileItemWriter` and copy header line from input file to output file.
  RetrySampleItemWriter<T> | Simulates temporary output trouble - requires to retry 3 times to pass successfully.
  SummaryFooterCallback | Writes summary info in the footer of a file.