Configuring a Step
Despite the relatively short list of required dependencies for a Step, it is an
extremely complex class that can potentially contain many collaborators.
-
Java
-
XML
When using Java configuration, you can use the Spring Batch builders, as the following example shows:
Java Configuration
/**
* Note the JobRepository is typically autowired in and not needed to be explicitly
* configured
*/
@Bean
public Job sampleJob(JobRepository jobRepository, Step sampleStep) {
return new JobBuilder("sampleJob", jobRepository)
.start(sampleStep)
.build();
}
/**
* Note the TransactionManager is typically autowired in and not needed to be explicitly
* configured
*/
@Bean
public Step sampleStep(JobRepository jobRepository, (2)
PlatformTransactionManager transactionManager) { (1)
return new StepBuilder("sampleStep", jobRepository)
.<String, String>chunk(10, transactionManager) (3)
.reader(itemReader())
.writer(itemWriter())
.build();
}
1
transactionManager: Spring’s PlatformTransactionManager that begins and commits
transactions during processing.
2
repository: The Java-specific name of the JobRepository that periodically stores
the StepExecution and ExecutionContext during processing (just before committing).
3
chunk: The Java-specific name of the dependency that indicates that this is an
item-based step and the number of items to be processed before the transaction is
committed.
Note that
repository defaults to jobRepository (provided through @EnableBatchProcessing)
and transactionManager defaults to transactionManager (provided from the application context).
Also, the ItemProcessor is optional, since the item could be
directly passed from the reader to the writer.
To ease configuration, you can use the Spring Batch XML namespace, as the following example shows:
XML Configuration
<job id="sampleJob" job-repository="jobRepository"> (2)
<step id="step1">
<tasklet transaction-manager="transactionManager"> (1)
<chunk reader="itemReader" writer="itemWriter" commit-interval="10"/> (3)
</tasklet>
</step>
</job>
1
transaction-manager: Spring’s PlatformTransactionManager that begins and commits
transactions during processing.
2
job-repository: The XML-specific name of the JobRepository that periodically stores
the StepExecution and ExecutionContext during processing (just before committing). For
an in-line <step/> (one defined within a <job/>), it is an attribute on the <job/>
element. For a standalone <step/>, it is defined as an attribute of the <tasklet/>.
3
commit-interval: The XML-specific name of the number of items to be processed
before the transaction is committed.
Note that
job-repository defaults to jobRepository and
transaction-manager defaults to transactionManager. Also, the ItemProcessor is
optional, since the item could be directly passed from the reader to the writer.
The preceding configuration includes the only required dependencies to create a item-oriented step:
-
reader: TheItemReaderthat provides items for processing. -
writer: TheItemWriterthat processes the items provided by theItemReader.