concept Tasklet in category spring

This is an excerpt from Manning's book Spring Batch in Action. Login to get full access to this book.

Spring Batch provides an extension point to handle processing in a batch process step: the Tasklet. You implement a Tasklet that decompresses a ZIP archive into its source flat file. The following listing shows the implementation of the DecompressTasklet class.

Listing 11.3. The echo Tasklet

package com.manning.sbia.ch11; import org.springframework.batch.core.StepContribution; import org.springframework.batch.core.scope.context.ChunkContext; import org.springframework.batch.core.step.tasklet.Tasklet; import org.springframework.batch.repeat.RepeatStatus; public class EchoJobParametersTasklet implements Tasklet { @Override public RepeatStatus execute(StepContribution contribution, ChunkContext chunkContext) throws Exception { System.out.println(chunkContext.getStepContext().getJobParameters()); return RepeatStatus.FINISHED; } }

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Test class	Spring Batch domain object
ImportValidatorTest	JobParametersValidator
CompositeItemProcessorTest	ItemProcessor
ProductFieldSetMapperTest	ItemReader
PriceMandatoryValidatorTest	Validator in an ItemProcessor
PositivePriceValidatorTest	Validator in an ItemProcessor
ProductItemWriterMockTest	ItemWriter
ProductItemListener	StepListener
NextDeciderTest	JobExecutionDecider
CleanTaskletTest	Tasklet

The Test module opens up Spring Batch domain objects to be tested. Classes like JobExecutionDecider and Tasklet, for example, have APIs that require the types of objects supplied by MetaDataInstanceFactory.

Testing a Tasklet

You can also manipulate complex Spring Batch domain objects like a ChunkContext (a requirement of the Tasklet API) with the MetaDataInstanceFactory class. The following listing demonstrates testing such a tasklet.

Listing 14.12. Testing a simple tasklet with Spring Batch domain mocks

In the CleanTaskletTest class, you create a ChunkContext to test the Tasklet, which doesn’t require any dependencies. The implementation of the CleanTasklet class always returns RepeatStatus.FINISHED.