Spring Batch: Footer callback of multiple file writer not giving exact count - spring

Question

If item writers are writing 2 records to file A and 1 record in file B then Trailer count of both the files(A & B) are 3.
I have a reader, processor and ClassifierCompositeItemWriter. In classifier i have two item writers those are giving valid outputs but the footer callback is not proper. in both the file trailer count is same though the record counts are different.
<batch:job id="abc-job" parent="xyzJob">
<batch:step id="inputfile">
<batch:tasklet>
<batch:chunk reader="itemReader" processor="itemProcessor" writer="itemWriter" commit-interval="1000" >
<batch:streams>
<batch:stream ref="AFileWriter"/>
<batch:stream ref="BFileWriter"/>
</batch:streams>
</batch:chunk>
</batch:tasklet>
</batch:step>
</batch:job>
<beans:bean id="itemWriter" class="org.springframework.batch.item.support.ClassifierCompositeItemWriter">
<beans:property name="classifier" ref="classifier" />
</beans:bean>
<beans:bean id="classifier" class="org.springframework.batch.classify.BackToBackPatternClassifier">
<beans:property name="routerDelegate">
<beans:bean class="com.abc.classifier.MyClassifier" />
</beans:property>
<beans:property name="matcherMap">
<beans:map>
<beans:entry key="A" value-ref="AFileWriter" />
<beans:entry key="B" value-ref="BFileWriter" />
</beans:map>
</beans:property>
</beans:bean>
<beans:bean id="1FileWriter" parent="parentItemWriter1">
<beans:property name="name" value="AFileWriter"/>
<beans:property name="resource" ref="AFile"/>
</beans:bean>
<beans:bean id="2FileWriter" parent="parentItemWriter2">
<beans:property name="name" value="BFileWriter"/>
<beans:property name="resource" ref="BFile"/>
</beans:bean>
Footer callback-
public class ItemCountFooterCallback implements FlatFileFooterCallback
{
private AtomicInteger count;
public ItemCountFooterCallback(final AtomicInteger count)
{
this.count = count;
}
public void writeFooter(final Writer writer) throws IOException
{
writer.append("Trailer " + this.count.toString());
}
}
I expect the output of A and B file's trailer record to be exact number rows of that particular file.

Answer 1

footerCallback is registered at the step level, hence it will use the write.count of the step, which is the total count of written items (3 in your case).
What you can do is to have a write count for each writer (writer1.count and writer2.count for example) and set a footer callback on each writer (not at the step level). Each footer callback should write the item count of the writer it is attached to.