When creating batches to be invoked by a scheduler, it is very important to correctly manage the JVM exit codes.
By convention, the JVM ends with an exit code equal to zero if there were no problems, otherwise with an exit code greater than zero.
In this way if the batch is not terminated correctly, interpreting the exit code, the scheduler can for example inform the application manager via email, or adopt strategies to relaunch or recover the batch itself, or terminate a job box.
If you use Spring Boot to start a Spring Batch-based batch, the JVM always ends with an exit code of zero, even in the case of runtime exceptions. In order to correctly manage the JVM exit codes, it is necessary to intervene by means of an ExitCodeGenerator.
The application stack is composed of:
Spring Core 4.0.7
Spring Boot 1.1.8
Spring Batch 3.0.1
in the class that configures the batch, we need to add the following methods:
@Bean public JobExecutionExitCodeGenerator jobExecutionExitCodeGenerator() {
return new JobExecutionExitCodeGenerator();
}
protected JobExecution addToJobExecutionExitCodeGenerator(JobExecution jobExecution) {
JobExecutionExitCodeGenerator jobExecutionExitCodeGenerator = jobExecutionExitCodeGenerator(); jobExecutionExitCodeGenerator.onApplicationEvent(new JobExecutionEvent(jobExecution)); return jobExecution;
}
as ExitCodeGenerator we can use the default implementation of Spring Boot which is JobExecutionExitCodeGenerator. So in the addToJobExecutionExitCodeGenerator method we pass the jobExecution to the exit code generator forcing the creation of the JobExecutionEvent event. When we launch the job, we must force the call to the addToJobExecutionExitCodeGenerator method:
addToJobExecutionExitCodeGenerator(jobLauncher.run(job(), jobParameters(jobParametersMap)));
In this way, when we end the batch in the Application class, the exit code will be the one actually returned from the batch:
int exitCode SpringApplication.exit(SpringApplication.run(batchConfiguration, args)); System.exit(exitCode);
Giancarlo Parma 