Storing in JobExecutionContext from tasklet and accessing in another tasklet

Question

I have a requirement in which a tasklet, stores all the files in the directories in an arraylist. The size of the list is stored in the job execution context. Later this cou

Answer 1

you have at least 4 possibilities:

1. use the ExecutionPromotionListener to pass data to future steps
2. use a (spring) bean to hold inter-step data, e.g. a ConcurrentHashMap
   • without further action this data won't be accessible for a re-start
3. access the JobExecutionContext in your tasklet, should be used with caution, will cause thread problems for parallel steps
4. use the new jobscope (introduced with spring batch 3)

Code Example for accessing JobExecution from Tasklet:

1. setting a value

   public class ChangingJobExecutionContextTasklet implements Tasklet {
   
       /** {@inheritDoc} */
       @Override
       public RepeatStatus execute(StepContribution contribution, ChunkContext chunkContext) throws Exception {
           // set variable in JobExecutionContext
           chunkContext
                   .getStepContext()
                   .getStepExecution()
                   .getJobExecution()
                   .getExecutionContext()
                   .put("value", "foo");
   
           // exit the step
           return RepeatStatus.FINISHED;
       }
   
   }
   

2. extracting a value

   public class ReadingJobExecutionContextTasklet implements Tasklet {
   
       private static final Logger LOG = LoggerFactory.getLogger(ChangingJobExecutionContextTasklet.class);
   
       /** {@inheritDoc} */
       @Override
       public RepeatStatus execute(StepContribution contribution, ChunkContext chunkContext) throws Exception {
           // pull variable from JobExecutionContext
           String value = (String) chunkContext
                                       .getStepContext()
                                       .getStepExecution()
                                       .getJobExecution()
                                       .getExecutionContext()
                                       .get("value");
   
           LOG.debug("Found value in JobExecutionContext:" + value);
   
           // exit the step
           return RepeatStatus.FINISHED;
       }
   }
   

i created code examples for the first 3 solutions in my spring-batch-examples github repository, see module complex and package interstepcommunication