Spring boot cron expression scheduling, calling onApplicationEvent of ApplicationListener

Question

I have written a StartupListener by implementing ApplicationListener and overriding the method: onApplicationEvent(ContextRefreshedEvent event).

@Component
public class StartupListener implements ApplicationListener<ContextRefreshedEvent> {

  private static Logger logger = LoggerFactory.getLogger(StartupListener.class);

  @Value("${create.file.some.merchant}")
  private boolean createMerchantAFile;

  @Override
  public void onApplicationEvent(ContextRefreshedEvent event) {
    logger.info("Application context started");

    if (createMerchantAFile) {
      EmbeddedResponse emb = null;
      file = ReportConstants.MERCHANT_A+ ReportConstants.FILE_FORMAT;
      try {
        emb = genericServices.readJsonFile("merA.json");
        generateReport.generateExcelFile(emb, file, "MerchantA");
      } catch (IOException ioe) {
        logger.error("IO Exception while reading JSON file. Message: ", ioe);
      } catch (Exception e) {
        logger.error("Exception while reading JSON file. Message", e);
      }
      createMerchantAFile= false;
    }
  }
}

Inside this method, I am trying to create some files based on whether a boolean value corresponding to file is true or not.

This boolean value is being read from "application.properties" file by using @Value annotation.

This StartupListener works fine.

Now I wish to generate these files by scheduling them, so I added @EnableScheduling to my main class file, and created a new java file with a method:

@Component
public class FileGenerationScheduler {

  @Autowired
  StartupListener startupListener;

  @Scheduled(cron = "${file.gen.cron}")
  public void generateFileWithCron() {
    startupListener.onApplicationEvent(null); //passing null here
  }
}

This method gets called on the specified cron expression but all the @Value boolean values are not read from "application.properties". So by default these values will be false (instance variables)

@Value("${create.file.some.merchant}")
private boolean createMerchantAFile;

This is present in StartupListener and is now false. So nothing is created.

How can I make sure that these values are read from application.prop even when called via scheduler ?

Answer 1

Create a service and add all the logic in it including the fetching of the value from the property find . Inject that bean inside the listener and the scheduler class.