Spring Batch Custom Writer with FooterCallback and Header callback - spring-batch

Question

I am trying to add a header and footer in a custom writer by implementing the header callback and footercallback in my custom writer call .
Write method is successful . But write header and writefooter are not called .
public class CustomOAFileItemWriter extends StepExecutionListenerSupport implements ItemWriter<OAExtract>,FlatFileHeaderCallback,FlatFileFooterCallback{
public void write(List<? extends OAExtract> oaExtractList) throws Exception {
FileOutputStream fs = new FileOutputStream("C:\\archivedFiles\\out.bin");
}
public void writeHeader(Writer writer) throws IOException {
System.out.println("Writing Header record");
}
public void writeFooter(Writer writer) throws IOException {
System.out.println("Writing Footerrecord");
}
Can someone with Spring batch experience help me with this?
Thanks,
Rai

Answer 1

You solution is opposite to SB philosophy: reuse and delegation. And you are using none of them.
You don't need a custom ItemWriter but
Create a FlatFileItemWriter with your custom header/footer callback
Create the listener you want (I see you extend StepExecutionListenerSupport) and attach to your step.

Answer 2

If you look at the source code for FlatFileItemWriter you will see that it calls the header callback method at doOpen() and footer callback method at doClose(). Since your not making use of the standard FlatFileItemWriter you will have write explicit code just like that in the FlatFileItemWriter.
http://grepcode.com/file/repo1.maven.org/maven2/org.springframework.batch/spring-batch-infrastructure/3.0.1.RELEASE/org/springframework/batch/item/file/FlatFileItemWriter.java#FlatFileItemWriter