[FIXED] Spring batch won't run job twice

Issue

I developed two different batches, let's say they're named as batch1 and batch2. In an integration test, I'm trying to prove that the execution of twice of the same batch (batch1 then batch1 for instance) isn't duplicating data saved in database in the writer.

The issue I face is that the first batch is running successfully, but the second isn't doing anything (reader, processor, writer are not called). However, the batch status is marked as COMPLETED.

Here's the code:

  @Test
  void testBatchWorksIfJobIsRanTwice()
      throws JobInstanceAlreadyCompleteException, JobExecutionAlreadyRunningException, JobParametersInvalidException, JobRestartException {

    // given
    createData();

    // when
    JobExecution firstJobExecution = runJobAndGetExecution("batch1_id1", jobRepository, job);
    assertEquals(BatchStatus.COMPLETED, firstJobExecution.getStatus());

    createMoreData();
    JobExecution secondJobExecution = runJobAndGetExecution("batch1_id2", jobRepository, job);
    assertEquals(BatchStatus.COMPLETED, secondJobExecution.getStatus());

    // then
    // assertions on data
  }

  public static JobExecution runJobAndGetExecution(String jobId, JobRepository jobRepository, Job job)
      throws JobInstanceAlreadyCompleteException, JobExecutionAlreadyRunningException, JobParametersInvalidException, JobRestartException {
    JobParameters param = new JobParametersBuilder()
        .addString("JobID", jobId)
        .addLong("currentTime", System.currentTimeMillis())
        .toJobParameters();

    SimpleJobLauncher launcher = new SimpleJobLauncher();
    launcher.setJobRepository(jobRepository);
    launcher.setTaskExecutor(new SyncTaskExecutor());

    return launcher.run(job, param);
  }

Please note that I pass a timestamp param in the job parameters to ensure that params are different.

Please also note that running the two different batches one after the other (batch1 and then batch2 is working fine, but batch1 then batch1 or batch2 then batch2 is not)

Any idea why it seems to run ? (I put some breakpoints and everything seems to happen correctly, just the reader, processer and writer are not called).

Solution

I resolved it. It was a misconception of the reader I implemented that was never reinitializing data, because I missunderstood the way reader works. The reader is called only once even if we're running the job 10 times. The comment from Mahmoud Ben Hassine on the post is complety right

Answered By - Quentin Lerebours
Answer Checked By - David Marino (JavaFixing Volunteer)