DSL spring integration flow for polling for files

InboundFileIntegration.java

    @Bean
    public IntegrationFlow inboundFileIntegration(@Value("${inbound.file.poller.fixed.delay}") long period,
                                                  @Value("${inbound.file.poller.max.messages.per.poll}") int maxMessagesPerPoll,
                                                  TaskExecutor taskExecutor,
                                                  MessageSource<File> fileReadingMessageSource) {
        return IntegrationFlows.from(fileReadingMessageSource,
                c -> c.poller(Pollers.fixedDelay(period)
                        .taskExecutor(taskExecutor)
                        .maxMessagesPerPoll(maxMessagesPerPoll)
                        .transactionSynchronizationFactory(transactionSynchronizationFactory())
                        .transactional(transactionManager())))
                .transform(Files.toStringTransformer())
                .channel(ApplicationConfiguration.INBOUND_CHANNEL)
                .get();
    }

    @Bean
    TaskExecutor taskExecutor(@Value("${inbound.file.poller.thread.pool.size}") int poolSize) {
        ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
        taskExecutor.setCorePoolSize(poolSize);
        return taskExecutor;
    }