SpringOne 2020 What’s New in Spring Batch? Mahmoud Ben Hassine, Principal Software Engineer at VMware

1. What’s new in Spring Batch 4.3?
Mahmoud Ben Hassine
September 2–3, 2020
springone.io

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presentation.
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3. About me
3
• Principal Software Engineer at VMware
• Spring Batch Co-Lead
• Open Source enthusiast
Github: @benas
Twitter: @b_e_n_a_s
Mahmoud Ben Hassine

4. Agenda
4
• Current status
• What’s new in Spring Batch 4.3?
• New features
• Performance improvements
• Dependencies updates
• Deprecations and technical debt
• What’s next?
• Q+A

5. Current status
(Sep 2020)

6. History of Spring Batch (1/2)
6
• Step scope
• Chunk-oriented processing
• Remote chunking/partitioning
• Java 5
• Spring Framework 3
v2.0
Apr 11, 2009
• Initial APIs
• Item-oriented processing
• XML configuration
• Java 1.4
• Spring Framework 2.5
• Job scope
• JSR-352 support
• SQLite support
• Spring Batch Integration
• Spring Boot support
• Builders for readers
• Builders for writers
• Java 8
• Spring Framework 5
v3.0
May 22, 2014
v1.0
Mar 28, 2008
v4.0
Dec 1, 2017

7. History of Spring Batch (2/2)
7
• @SpringBatchTest annotation
• @EnableBatchIntegration
annotation
• JSR 380 Bean Validation support
• Json reader/writer
• JSR 305 support
v4.1
Oct 29, 2018
• Apache Avro support
• Apache Kafka support
• Micrometer support
• Performance improvements
• Java 14 records support
• GraalVM support
• Kafka support refinement
• Performance improvements
• Deprecations
• Builders for readers
• Builders for writers
• Java 8
• Spring Framework 5
v4.3
Oct XX, 2020
v4.2
Oct 02, 2019
v4.0
Dec 1, 2017
v5.0
XXX XX, 20XX
• Spring Framework 6
• Java XX
• TBD

8. History of Spring Batch (2/2)
8
• @SpringBatchTest annotation
• @EnableBatchIntegration
annotation
• JSR 380 Bean Validation support
• Json reader/writer
• JSR 305 support
v4.1
Oct 29, 2018
• Apache Avro support
• Apache Kafka support
• Micrometer support
• Performance improvements
• Java 14 records support
• GraalVM support
• Kafka support refinement
• Performance improvements
• Deprecations
• Builders for readers
• Builders for writers
• Java 8
• Spring Framework 5
v4.3
Oct XX, 2020
v4.2
Oct 02, 2019
v4.0
Dec 1, 2017
v5.0
XXX XX, 20XX
• Spring Framework 6
• Java XX
• TBD

9. What’s new in v4.3?
(currently in M2)

10. New features

11. Java 14 records support
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• Use records as items in chunk-oriented steps
• Leverage Spring Framework support for records
id,name
1,foo
2,bar
persons.csv
FlatFileItemReader<Person> reader = new FlatFileItemReaderBuilder<Person>()
.name("personItemReader")
.resource(new FileSystemResource("persons.csv"))
.delimited()
.names("id", "name")
.targetType(Person.class)
.build();
public class Person {
private int id;
Private String name;
// constructors
// getters and setters
// equals and hashcode
// toString
}
public record Person(int id, String name) {}

12. GraalVM support
12
• Leverage Spring Framework support for GraalVM
• Spring Batch jobs run correctly on GraalVM
• Reflection
• Proxies
• etc
Faster startup time + Better memory usage

13. Kafka support refinement
13
• Ability to start reading from a custom offset in a given partition
• Ability to start reading from the offset stored in Kafka
Image source: http://kafka.apache.org/intro
v4.3: read from custom offsetv4.2: read from the beginning

14. Support for annotation-based job execution
listeners
14
class MyListener implements JobExecutionListener {
@Override
public void beforeJob(JobExecution jobExecution) {
// do something before job execution
}
@Override
public void afterJob(JobExecution jobExecution) {
// do something after job execution
}
}
class MyListener {
@BeforeJob
public void beforeJob(JobExecution jobExecution) {
// do something before job execution
}
@AfterJob
public void afterJob(JobExecution jobExecution) {
// do something after job execution
}
}
v4.2: interface-based listeners v4.3: interface-based + annotation-based
listeners

15. Add SynchronizedItemStreamWriter
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@Bean
public StaxEventItemWriter<Person> itemWriter() {
Jaxb2Marshaller marchaller = new Jaxb2Marshaller();
marchaller.setClassesToBeBound(Person.class);
return new StaxEventItemWriterBuilder<Person>()
.name("personItemWriter")
.resource(new FileSystemResource("persons.xml"))
.marshaller(marchaller)
.rootTagName("persons")
.build();
}
Expected output
• Some item writers are not safe to use in a multi-threaded step
(StaxEventItemWriter, JsonItemWriter, etc)
<persons>
<person>
<id>1</id>
<name>foo</name>
</person>
<person>
<id>2</id>
<name>foo</name>
</person>
</persons>
Actual output
<persons>
<name>foo</name>
<person>
<id>1</id>
</person>
<id>2<person>
<name>foo</name>
</id>
</person>
</persons>
Item writer bean
definition

16. Add SynchronizedItemStreamWriter
16
@Bean
public SynchronizedItemStreamWriter<Person> itemWriter() {
Jaxb2Marshaller marchaller = new Jaxb2Marshaller();
marchaller.setClassesToBeBound(Person.class);
StaxEventItemWriter<Person> personWriter = new StaxEventItemWriterBuilder<Person>()
.name("personItemWriter")
.resource(new FileSystemResource("persons.xml"))
.marshaller(marchaller)
.rootTagName("persons")
.build();
SynchronizedItemStreamWriter<Person> synchronizedPersonWriter = new SynchronizedItemStreamWriter<>();
synchronizedPersonWriter.setDelegate(personWriter);
return synchronizedPersonWriter;
}
• Some item writers are not safe to use in a multi-threaded step
(StaxEventItemWriter, JsonItemWriter, etc)
=> SynchronizedItemStreamWriter to the
rescue!

17. Other new features
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• Add JpaNamedQueryProvider
• Add encoding parameter in StaxEventItemReader
• Micrometer support improvements
• Add DataFieldMaxValueJobParametersIncrementer
• etc
https://spring.io/blog/2020/08/13/spring-batch-4-3-0-m2-is-out
https://spring.io/blog/2020/06/26/spring-batch-4-3-0-m1-is-released-now

18. Performance improvements

19. for(item in chunk) {
mongoTemplate.save(item);
}
v4.2 (pseudo
code)
BulkOperations bulkOperations = mongoTemplate.bulkOps();
for(item in chunk) {
bulkOperation.add(item);
}
bulkOperations.execute();
v4.3 (pseudo
code)
Use bulk operations in MongoItemWriter
19
https://github.com/benas/spring-batch-lab/tree/master/issues/gh3713

20. for(item in chunk) {
repository.save(item);
}
v4.2 (pseudo
code)
repository.saveAll(items);
v4.3 (pseudo
code)
Use bulk operations in RepositoryItemWriter
20
https://github.com/benas/spring-batch-lab/tree/master/issues/gh3720

21. int getStepExecutionCount(JobInstance jobInstance, String stepName) {
int count = 0;
List<JobExecution> jobExecutions = findJobExecutions(jobInstance);
for (JobExecution jobExecution : jobExecutions) {
List<StepExecution> stepExecutions =
findStepExecutions(jobExecution);
count += countStepExecutions(stepExecutions, stepName);
}
return count;
}
v4.2 (pseudo
code)
v4.3 (pseudo
code)
int getStepExecutionCount(JobInstance jobInstance, String stepName) {
String query = “select count(id) from ... where ...”;
return jdbcTemplate.queryForObject(
query,
new Object[] {jobInstance, stepName},
Integer.class);
}
Job/Step start time improvement
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https://github.com/benas/spring-batch-lab/tree/master/issues/gh3657

22. Dependencies updates

23. Dependencies updates
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• Spring Framework 5.3
• Spring Integration 5.4
• Spring Data 2020.0
• Spring AMQP 2.3.0
• Spring for Apache Kafka 2.6.0
• Micrometer 1.5.3

24. Deprecations and
technical debt

25. Deprecations and technical debt
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• API deprecation in preparation for v5
• Improve build process
• Improve test infrastructure
• Docker-based tests with testcontainers
• Junit 5
• Improve test coverage
• etc

26. What’s next?

27. Release plan for 2020+
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• Spring Batch 4.3.0-RC1 (Sep 16, 2020) and 4.3.0 (Oct, 2020)
• Bug fix releases for Spring Batch v4.2.x (Same EOL as Spring Boot v2.3)
• Bug fix releases for Spring Batch v4.3.x (Same EOL as Spring Boot v2.4)
• Spring Batch v5 (Spring Framework v6)

28. Thank you!
Q+A
springone.slack.com: #session-whats-new-in-spring-batch
#springone@springon
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