[Question] Any way to set decider first?

[acktsap]

In xml based job configuration, we can set decider first like this.

<job id="decisionJob1" >
    <decision id="decider1" decider="stepFlowDecider">
        <end on="EXIT" exit-code="COMPLETED"/>
        <next on="*" to="job1Step1" />
    </decision>

    <step id="job1Step1">
        <tasklet ref="createFileTasklet"/>
    </step>
</job>

But when using code based job configuration, no way to start with decider. JobBuilder only provides start methods taking Step, Flow only.

spring-batch/spring-batch-core/src/main/java/org/springframework/batch/core/job/builder/JobBuilder.java

Lines 53 to 78 in 972951a

	/**
	* Create a new job builder that will execute a step or sequence of steps.
	* @param step a step to execute
	* @return a {@link SimpleJobBuilder}
	*/
	public SimpleJobBuilder start(Step step) {
	return new SimpleJobBuilder(this).start(step);
	}
	/**
	* Create a new job builder that will execute a flow.
	* @param flow a flow to execute
	* @return a {@link SimpleJobBuilder}
	*/
	public JobFlowBuilder start(Flow flow) {
	return new FlowJobBuilder(this).start(flow);
	}
	/**
	* Create a new job builder that will execute a step or sequence of steps.
	* @param step a step to execute
	* @return a {@link SimpleJobBuilder}
	*/
	public JobFlowBuilder flow(Step step) {
	return new FlowJobBuilder(this).start(step);
	}

It there any way to set decider first on code based job configuration?

[baezzys]

If you use SimpleJobBuilder instead of JobBuilder, you can create a JobFlowBuilder that starts with a decider.

This is an example.

		JobExecutionDecider decider = new JobExecutionDecider() {
			private int count = 0;

			@Override
			public FlowExecutionStatus decide(JobExecution jobExecution, @Nullable StepExecution stepExecution) {
				count++;
				return count < 2 ? new FlowExecutionStatus("ONGOING") : FlowExecutionStatus.COMPLETED;
			}
		};
		JobFlowBuilder builder = new SimpleJobBuilder(new JobBuilder("flow", jobRepository)).start(decider);

I hope this example works for you.

[acktsap]

Thank's for your workaround. But i'm looking for high level api using JobBuilder. Not concrete class JobFlowBuilder. As long as we can set JobExecutionDecider first, it seems natural to be able to set by using JobBuilder class.

[fmbenhassine]

For questions and support requests, we started using GitHub discussions, see Getting Help. Therefore, I am moving this to a discussion. We will change it to an issue if we validate a bug or a missing feature.

[fmbenhassine]

I agree with @acktsap , if it is possible to start a job with a decision in XML, it should be possible to do it in Java as well using the JobBuilder API. The JobFlowBuilder already provides a constructor to create a flow with a decider, so this feature could be implemented by adding the following two methods:

public class JobBuilder extends JobBuilderHelper<JobBuilder> {

++	public JobFlowBuilder start(JobExecutionDecider decider) {
++		return new FlowJobBuilder(this).start(decider);
++	}

}

public class FlowJobBuilder extends JobBuilderHelper<FlowJobBuilder> {

++	public JobFlowBuilder start(JobExecutionDecider decider) {
++		return new JobFlowBuilder(this, decider);
++	}

}

With that in place, we should be able to start a job flow with a decider in a consistent way as XML:

@Bean
public Job job(JobRepository jobRepository, JobExecutionDecider decider) {
	return new JobBuilder("myJob", jobRepository)
				.start(decider)
				.build()// build the fow
			.build(); // build the job
}

I will change this discussion into a feature request and move it to the issue tracker. Contributions are welcome!