This version is still in development and is not considered stable yet. For the latest stable version, please use spring-cloud-task 3.3.0!

Batch

This section goes into more detail about Spring Cloud Task’s integration with Spring Batch. Tracking the association between a job execution and the task in which it was executed.

Associating a Job Execution to the Task in which It Was Executed

Spring Boot provides facilities for the execution of batch jobs within a Spring Boot Uber-jar. Spring Boot’s support of this functionality lets a developer execute multiple batch jobs within that execution. Spring Cloud Task provides the ability to associate the execution of a job (a job execution) with a task’s execution so that one can be traced back to the other.

Spring Cloud Task achieves this functionality by using the TaskBatchExecutionListener. By default, this listener is auto configured in any context that has both a Spring Batch Job configured (by having a bean of type Job defined in the context) and the spring-cloud-task-batch jar on the classpath. The listener is injected into all jobs that meet those conditions.

Overriding the TaskBatchExecutionListener

To prevent the listener from being injected into any batch jobs within the current context, you can disable the autoconfiguration by using standard Spring Boot mechanisms.

To only have the listener injected into particular jobs within the context, override the batchTaskExecutionListenerBeanPostProcessor and provide a list of job bean IDs, as shown in the following example:

public static TaskBatchExecutionListenerBeanPostProcessor batchTaskExecutionListenerBeanPostProcessor() {
	TaskBatchExecutionListenerBeanPostProcessor postProcessor =
		new TaskBatchExecutionListenerBeanPostProcessor();

	postProcessor.setJobNames(Arrays.asList(new String[] {"job1", "job2"}));

	return postProcessor;
}

You can find a sample batch application in the samples module of the Spring Cloud Task Project, here.

Batch Informational Messages

Spring Cloud Task provides the ability for batch jobs to emit informational messages. The “Spring Batch Events” section covers this feature in detail.

Batch Job Exit Codes

As discussed earlier, Spring Cloud Task applications support the ability to record the exit code of a task execution. However, in cases where you run a Spring Batch Job within a task, regardless of how the Batch Job Execution completes, the result of the task is always zero when using the default Batch/Boot behavior. Keep in mind that a task is a boot application and that the exit code returned from the task is the same as a boot application. To override this behavior and allow the task to return an exit code other than zero when a batch job returns an BatchStatus of FAILED, set spring.cloud.task.batch.fail-on-job-failure to true. Then the exit code can be 1 (the default) or be based on the specified ExitCodeGenerator)

This functionality uses a new ApplicationRunner that replaces the one provided by Spring Boot. By default, it is configured with the same order. However, if you want to customize the order in which the ApplicationRunner is run, you can set its order by setting the spring.cloud.task.batch.applicationRunnerOrder property. To have your task return the exit code based on the result of the batch job execution, you need to write your own CommandLineRunner.