[FIXED] how to avoid starting duplicate spring batch jobs?

Issue

I have a spring batch process which does data reading from the database and writing to file. Basically, the scenario is, that the user can send a request and the job will start and execute the process. But the issue is if the user sends the request 5 times there will be 5 different spring jobs started and running. But those are duplicates. So is there a way that we can avoid or block creating duplicate spring jobs?

Solution

You can create a JobExecutionListener that stops the current job execution if another one is already running and configure your job with that listener...

public class SingleExecutionJobListener implements JobExecutionListener {

    private static String MATCH_ALL_PATTERN = ".*";

    @Autowired
    private JobExplorer jobExplorer;

    @Autowired
    private JobRegistry jobRegistry;

    private String jobNamePattern = MATCH_ALL_PATTERN;

    @Override
    public void beforeJob(JobExecution jobExecution) {
        Collection<String> jobNames = jobRegistry.getJobNames();
        for (String jobName : jobNames) {
            if (jobName.matches(StringUtils.defaultIfBlank(jobNamePattern, MATCH_ALL_PATTERN))) {
                Set<JobExecution> jobExecutions = jobExplorer.findRunningJobExecutions(jobName);
                if (CollectionUtils.isNotEmpty(jobExecutions)) {
                    for (JobExecution execution : jobExecutions) {
                        if (execution.getJobInstance().getId().compareTo(jobExecution.getJobInstance().getId()) != 0) {
                            jobExecution.stop();
                            throw new IllegalStateException(jobName + " instance " + execution.getJobInstance().getId()
                                + " is currently running. Please restart this job when " + jobName + " has finished.");
                        }
                    }
                }
            }
        }
    }

    @Override
    public void afterJob(JobExecution jobExecution) {}

    public String getJobNamePattern() {
        return jobNamePattern;
    }

    public void setJobNamePattern(String jobNamePattern) {
        this.jobNamePattern = jobNamePattern;
    }

}

Answered By - httPants
Answer Checked By - Katrina (JavaFixing Volunteer)