Why does the JobParameter.equals() method only compare their names?

[Sax388]

I'm a bit dumbfounded that it doesn't take the values into account:
https://github.com/spring-projects/spring-batch/blob/2cc7890be100034f66bab9b4297de93dfbfad3a3/spring-batch-core/src/main/java/org/springframework/batch/core/job/parameters/JobParameter.java#L66C1-L71C3

I'd like to understand the reasoning behind this as it tripped me 🙂.

PS Thanks for the great work with Spring Batch 6 (I tripped over 6.0.0 as well and was very happy when 6.0.1 fixed those issues).

[fmbenhassine]

The reason is that a job parameter has no meaning outside the set of JobParameters that identifies a job instance (This was the case since the very early stages and I agree with that). It does not make sense to have two job parameters with the same name within the same JobParameters instance, which is actually a namespace of job parameters. Therefore, the value of a parameter does not really matter in the equality within a set of job parameters. There are some explanations about this in the javadocs of JobParameter and JobParameters.

PS Thanks for the great work with Spring Batch 6 (I tripped over 6.0.0 as well and was very happy when 6.0.1 fixed those issues).

Thank you! Indeed, as with every major overhaul, I was expecting some bumps and corner cases that were missed.. But I believe with 6.0.1 and the upcoming 6.0.2 we will have a strong foundation to ensure the long-term sustainability of the project. I wrote about this in #5156.

[Sax388]

Thank you for the swift reply!

I'm not sure if I'm doing something "wrong" then. In my case I need to run jobs repeatedly (so I'm adding

new JobParametersBuilder()
    .addLong(
        "run.id",
        System
            .currentTimeMillis()) // to allow the same report to be generated multiple times

to the JobParameters) but not concurrently i.e. I check before running the job if the (identifying) job parameters are equal excluding the run.id. For this I need to compare the values with

public static boolean areJobParameterValuesEqual(JobParameters first, JobParameters second) {
  if (first.parameters().size() != second.parameters().size()) {
    return false;
  }

  for (var parameter : first.parameters()) {
    var secondValue = second.getParameter(parameter.name());
    if (secondValue == null || !Objects.equals(parameter.value(), secondValue.value())) {
      return false;
    }
  }

  return true;
}

Is this the best practice for a scenario where you need repeatability without concurrently running the same job?