Spring Integration : get poll expression from database

Question

I have an FTP message source and I want to enable the user to configure the poll frequency through an application.

This is the current configuration of the Inbound channel adapter

@Bean
@InboundChannelAdapter(channel = "fromSmartpath", poller = @Poller(cron = "0 15 8 ? * MON,TUE,WED,THU,FRI,SAT"))
public MessageSource<File> sftpMessageSource() throws SftpException {
    SftpInboundFileSynchronizingMessageSource source = new SftpInboundFileSynchronizingMessageSource(
            sftpInboundFileSynchronizer());
    source.setLocalDirectory(new File(Constants.LOCAL_REPOSITORY_PATH));
    source.setAutoCreateLocalDirectory(true);
    source.setLocalFilter(new FileSystemPersistentAcceptOnceFileListFilter(metaDataStore(), "metastore"));
    return source;
}

My goal is to retrieve the cron expression from the database. Is There a way to achieve this?

Thank you

Answer 1

The cron expression ends up in the CronTrigger. You can develop some service which SELECT an expression from DB in its afterPropertiesSet() and returns it via getter. Then you declare a @Bean for the CronTrigger and call that getter from the service during its definition.

The @Poller on the @InboundChannelAdapter has a trigger option to refer to the existing bean.