Spring Batch listeners example

In Spring batch, there are six “listeners” to intercept the step execution, I believe the class name should be self-explanatory.

1. StepExecutionListener
2. ItemReadListener
3. ItemProcessListener
4. ItemWriteListener
5. ChunkListener
6. SkipListener

1. Listener Example

Three listener examples, do nothing but print out a message.

package com.mkyong.listeners;

import org.springframework.batch.core.ExitStatus;
import org.springframework.batch.core.StepExecution;
import org.springframework.batch.core.StepExecutionListener;

public class CustomStepListener implements StepExecutionListener {

	@Override
	public void beforeStep(StepExecution stepExecution) {
		System.out.println("StepExecutionListener - beforeStep");
	}

	@Override
	public ExitStatus afterStep(StepExecution stepExecution) {
		System.out.println("StepExecutionListener - afterStep");
		return null;
	}

}

package com.mkyong.listeners;

import org.springframework.batch.core.ItemReadListener;
import com.mkyong.Domain;

public class CustomItemReaderListener implements ItemReadListener<Domain> {

	@Override
	public void beforeRead() {
		System.out.println("ItemReadListener - beforeRead");
	}

	@Override
	public void afterRead(Domain item) {
		System.out.println("ItemReadListener - afterRead");
	}

	@Override
	public void onReadError(Exception ex) {
		System.out.println("ItemReadListener - onReadError");
	}

}

package com.mkyong.listeners;

import java.util.List;
import org.springframework.batch.core.ItemWriteListener;
import com.mkyong.Domain;

public class CustomItemWriterListener implements ItemWriteListener<Domain> {

	@Override
	public void beforeWrite(List<? extends Domain> items) {
		System.out.println("ItemWriteListener - beforeWrite");
	}

	@Override
	public void afterWrite(List<? extends Domain> items) {
		System.out.println("ItemWriteListener - afterWrite");
	}

	@Override
	public void onWriteError(Exception exception, List<? extends Domain> items) {
		System.out.println("ItemWriteListener - onWriteError");
	}

}

2. Batch Jobs

A batch job, attached above three listeners.

    <bean id="customStepListener" 
          class="com.mkyong.listeners.CustomStepListener" />
    <bean id="customItemReaderListener" 
          class="com.mkyong.listeners.CustomItemReaderListener" />
    <bean id="customItemWriterListener" 
          class="com.mkyong.listeners.CustomItemWriterListener" />

    <job id="readFileJob" xmlns="http://www.springframework.org/schema/batch">
	<step id="step1">
	    <tasklet>
		<chunk reader="multiResourceReader" writer="flatFileItemWriter"
			commit-interval="1" />
		    <listeners>
			<listener ref="customStepListener" />
			<listener ref="customItemReaderListener" />
			<listener ref="customItemWriterListener" />
		    </listeners>
	    </tasklet>
	</step>
    </job>

Assume 3 records from a csv file are loaded and write it somewhere, here’s the console output :

StepExecutionListener - beforeStep

ItemReadListener - beforeRead
ItemReadListener - afterRead
ItemWriteListener - beforeWrite
ItemWriteListener - afterWrite

ItemReadListener - beforeRead
ItemReadListener - afterRead
ItemWriteListener - beforeWrite
ItemWriteListener - afterWrite

ItemReadListener - beforeRead
ItemReadListener - afterRead
ItemWriteListener - beforeWrite
ItemWriteListener - afterWrite

StepExecutionListener - afterStep

Download Source Code

References

1. Intercepting Step Execution
2. StepExecutionListener JavaDoc
3. ItemReadListener JavaDoc
4. ItemProcessListener JavaDoc
5. ItemWriteListener JavaDoc
6. ChunkListener JavaDoc
7. SkipListener JavaDoc