Spring Integration AWS configuration fragment for synchronizing an S3 bucket directory

AmazonS3InboundSynchronizationMessageSourceConfig.java

    @Bean
    public MessageSource<?> amazonS3InboundSynchronizationMessageSource() {
        AWSCredentials credentials = new BasicAWSCredentials(this.accessKey, this.secretKey);
        AmazonS3InboundSynchronizationMessageSource messageSource = new AmazonS3InboundSynchronizationMessageSource();
        messageSource.setCredentials(credentials);
        messageSource.setBucket(bucket);
        messageSource.setMaxObjectsPerBatch(maxObjectsPerBatch);
        messageSource.setAcceptSubFolders(Boolean.valueOf(acceptSubFolders));
        messageSource.setRemoteDirectory(remoteDirectory);
        if (!fileNameWildcard.isEmpty()) {
            messageSource.setFileNameWildcard(fileNameWildcard);
        }
        String directory = System.getProperty(localDirectoryRef);
        if (!localSubdirectory.startsWith("/")) {
            localSubdirectory = "/" + localSubdirectory;
        }
        if (!localSubdirectory.endsWith("/")) {
            localSubdirectory = localSubdirectory + "/";
        }
        directory = directory + localSubdirectory;
        FileUtils.mkdir(directory);
        messageSource.setDirectory(new LiteralExpression(directory));
        return messageSource;
    }