spring batch incrementer is ignored - spring-batch

Question

I hava a spring batch (2.2.2) application and for some reason cannot make the job parameter incremeneter work. The step is declared as this :
<job id="job1" xmlns="http://www.springframework.org/schema/batch" incrementer="incrementer">
<step id="step1" parent="step" />
</job>
<bean id="incrementer" class="org.springframework.batch.core.launch.support.RunIdIncrementer" />
When I put a breakpoint into the incrementer it is not even called.
Calling the job two times with the same parameter gives the following exception :
A job instance already exists and is complete for parameters={fail=false}. If you want to run this job again, change the parameters.
I checked the official samples here
https://github.com/spring-projects/spring-batch-admin/tree/master/spring-batch-admin-sample
and it has the same problem

Answer 1

Old question, but still applies to current version (3.0.5):
If you are starting the job execution via
JobExecution jobExecution = launcher.run(job, jobParameters);
using e.g. the SimpleJobLauncher class, then the incrementer is never called. If you check the "callers" of the method Incrementer.getNext(JobParameters), the number of callers is limited:
org.springframework.batch.core.launch.support.CommandLineJobRunner
CommandLineJobRunner does the call to getNext() conditionally on "-next" before calling the launcher:
if (opts.contains("-next")) {
JobParameters nextParameters = getNextJobParameters(job);
Map<String, JobParameter> map = new HashMap<String, JobParameter>(nextParameters.getParameters());
map.putAll(jobParameters.getParameters());
jobParameters = new JobParameters(map);
}
JobExecution jobExecution = launcher.run(job, jobParameters);
org.springframework.batch.core.launch.support.SimpleJobOperator
This is used by the Spring Admin web application and it is basically the same implementation as in CommandLineJobRunner:
if (lastInstances.isEmpty()) {
parameters = incrementer.getNext(new JobParameters());
if (parameters == null) {
throw new JobParametersNotFoundException("No bootstrap parameters found for job=" + jobName);
}
}
else {
List<JobExecution> lastExecutions = jobExplorer.getJobExecutions(lastInstances.get(0));
parameters = incrementer.getNext(lastExecutions.get(0).getJobParameters());
}
logger.info(String.format("Attempting to launch job with name=%s and parameters=%s", jobName, parameters));
try {
return jobLauncher.run(job, parameters).getId();
}
catch (JobExecutionAlreadyRunningException e) {
throw new UnexpectedJobExecutionException(String.format(ILLEGAL_STATE_MSG, "job already running", jobName,
parameters), e);
}
So if you are using using the JobLauncher class for starting Jobs, must must take care of yourself for calling the incrementer before calling the jobLauncher to enhance the job parameter with your desired values.

Answer 2

I see that nobody gave you a correct answer so here is it (even if it is one year late maybe it will help others):
You can directly call the main function of the
CommandLineJobRunner class.
For example:
String[] args = new String[]{"spring/batch/jobs/helloWorldJob.xml", "helloWorldJob", "name(string)=Spring", "-next"};
CommandLineJobRunner.main(args);
Basically this is what you are doing when you are running Spring Batch from the command line (or any other java application in fact).

Answer 3

If you run with CommandLineJobRunner use the -next option else the best solution is to use a timestamp job parameter to make every job instance different from others.