Spring Batch- Write to two different file based on condition - spring-batch

Question

I want to write data to two different files. If my condition is true then write to x file otherwise to y file.
Currently I have a flat file item writer that writes all the data to one file. I want to specify two different files and based on condition data should go to perticular file.
<beans:bean id="itemWriter" class="org.springframework.batch.item.file.FlatFileItemWriter">
<beans:property name="resource">
<beans:bean class="org.springframework.core.io.FileSystemResource" scope="step">
<beans:constructor-arg value="${process.output.dir}/${output.file.name}_#{jobParameters['run.id']}.${output.file.extension}" type="java.lang.String" />
</beans:bean>
</beans:property>
<beans:property name="lineAggregator">
<beans:bean class="org.springframework.batch.item.file.transform.DelimitedLineAggregator">
<beans:property name="delimiter" value="|" />
<beans:property name="fieldExtractor">
<beans:bean class="com.abc.common.batch.item.file.transform.FormattingFieldExtractorDecorator">
<beans:property name="fieldExtractor">
<beans:bean class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor" >
<beans:property name="names" value="${output.field.names}" />
</beans:bean>
</beans:property>
<beans:property name="defaultDateFormat" value="yyyyMMdd" />
<beans:property name="defaultDecimalFormat" value="############0.00" />
</beans:bean>
</beans:property>
</beans:bean>
</beans:property>
<beans:property name="headerCallback">
<beans:bean class="com.abc.common.batch.item.file.HeaderWriter">
<beans:constructor-arg value="${output.column.names}" />
</beans:bean>
</beans:property>
<beans:property name="footerCallback">
<beans:bean class="com.abc.footer.ItemCountFooterCallback" >
<beans:constructor-arg name="count" ref="itemCount" />
</beans:bean>
</beans:property>
</beans:bean>

Answer 1

ClassifierCompositeItemWriter is the way to go. It uses a Classifier to classify items (this is where you would implement your condition) and multiple item writers (each one will write a specific "class" of items).
You can find an example here.
Hope this helps.

Answer 2

you can definitely do this , you can implement a custom item writer and then based on your conditions you can achieve the task of writing into different files.
But in this case - the condition and handling the file may hamper the performance of your application , you need to be careful with your implementation
Here I am just giving you the layout , you can write the implementation of writing in your file , first write the custom item writer -
https://www.programcreek.com/java-api-examples/index.php?api=org.springframework.batch.item.ItemWriter
And then implement a custom itemWriterListener - in which using the beforeWrite method - you can set a different resource
public class WriteListener implements ItemWriteListener{
#Autowire
ItemWrite writer;
public void beforeWrite(List items) {
condition 1 (){
writer.setResource(1)
}
condition 2 (){
writer.setResource(2)
}
}
public void onWriteError(Exception exception, List items) {
System.out.println("Error occurred when writing items!");
}
public void afterWrite(List items) {
}
}