title: How could I guarantee that only one JobInstance of a job run at the same time?
body: <p>Spring Batch documentation says: "<em>Spring Batch will make no attempt to stop them from being run concurrently</em>" (http://static.springsource.org/spring-batch/reference/html-single/index.html).</p>
  
  <p>But I would like to get an error if I try to run a job and there is an instance of that job running. Is it possible?</p>
  
  <p>I am using Spring Batch 2.1.8.</p>