使用 Spring 集成为文件轮询 S3 Bucket

Question

I am working on a project where I am required to poll S3 bucket for files and upload in a different S3 bucket. As a first step to implementing it, I am trying to poll S3 bucket for new files created and create them in my local directory using Spring Integration. To achieve that I have created a simple spring-boot application with maven with the below object polling configuration while handles the fileReading IntegrationFlow

@Configuration
@EnableIntegration
@IntegrationComponentScan
@EnableAsync
public class ObjectPollerConfiguration {
    @Value("${amazonProperties.bucketName}")
    private String bucketName;
    public static final String OUTPUT_DIR2 = "target2";
    @Autowired
    private AmazonClient amazonClient;
    @Bean
    public S3InboundFileSynchronizer s3InboundFileSynchronizer() {
        S3InboundFileSynchronizer synchronizer = new S3InboundFileSynchronizer(amazonClient.getS3Client());
        synchronizer.setDeleteRemoteFiles(true);
        synchronizer.setPreserveTimestamp(true);
        synchronizer.setRemoteDirectory(bucketName);            
        return synchronizer;
    }
    @Bean
    @InboundChannelAdapter(value = "s3FilesChannel", poller = @Poller(fixedDelay = "30"))
    public S3InboundFileSynchronizingMessageSource s3InboundFileSynchronizingMessageSource() {
        S3InboundFileSynchronizingMessageSource messageSource =
                new S3InboundFileSynchronizingMessageSource(s3InboundFileSynchronizer());
        messageSource.setAutoCreateLocalDirectory(true);
        messageSource.setLocalDirectory(new File("."));
        messageSource.setLocalFilter(new AcceptOnceFileListFilter<File>());
        return messageSource;
    }
    @Bean
    public PollableChannel s3FilesChannel() {
        return new QueueChannel();
    }
    @Bean
    IntegrationFlow fileReadingFlow() {
        return IntegrationFlows
                .from(s3InboundFileSynchronizingMessageSource(),
                        e -> e.poller(p -> p.fixedDelay(30, TimeUnit.SECONDS)))
                .handle(fileProcessor())
                .get();
    }
    @Bean
    public MessageHandler fileProcessor() {
        FileWritingMessageHandler handler = new FileWritingMessageHandler(new File(OUTPUT_DIR2));
        handler.setExpectReply(false); // end of pipeline, reply not needed
        return handler;
    }
}*

But when I start my application as a java application and upload files to S3, I don't see the target2 directory with file nor getting any logs corresponding to polling execution. Can someone help me to get it working ?

Answer 1

I think the problem that you don't use your OUTPUT_DIR2 property for local dir to push into.

Your code for local dir is like this:

messageSource.setLocalDirectory(new File("."));

This is fully not what you are looking for. Try to change it into the

messageSource.setLocalDirectory(new File(OUTPUT_DIR2));