Set S3 bucket dynamically using S3 Message Handler and Spring Integration - spring

Question

How can I pass in an 'asset' POJO to the S3MessageHandler using Spring Integration and change the bucket?
I would like to be able to change the bucket, based on a folder in the asset, to something like 'root-bucket/a/b/c.'
Each asset can potentially have a different sub-path.
#Bean
IntegrationFlow flowUploadAssetToS3()
{
return flow -> flow
.channel(this.channelUploadAsset)
.channel(c -> c.queue(10))
.publishSubscribeChannel(c -> c
.subscribe(s -> s
// Publish the asset?
.<File>handle((p, h) -> this.publishS3Asset(
p,
(Asset)h.get("asset")))
// Set the action
.enrichHeaders(e -> e
.header("s3Command", Command.UPLOAD.name()))
// Upload the file
.handle(this.s3MessageHandler())));
}
MessageHandler s3MessageHandler()
{
return new S3MessageHandler(amazonS3, "root-bucket");
}
Thanks to the answer below, I got this working like so:
final String bucket = "'my-root";
final Expression bucketExpression = PARSER.parseExpression(bucket);
final Expression keyExpression = PARSER.parseExpression("headers['asset'].bucket");
final S3MessageHandler handler = new S3MessageHandler(amazonS3, bucketExpression);
handler.setKeyExpression(keyExpression);
return handler;

Answer 1

There is bucketExpression option which is SpEL to let to resolve a bucket from the requestMessage:
private static SpelExpressionParser PARSER = new SpelExpressionParser();
MessageHandler s3MessageHandler() {
Expression bucketExpression =
PARSER.parseExpression("payload.bucketProperty");
return new S3MessageHandler(amazonS3, bucketExpression);
}
Also be aware that root-bucket/a/b/c. isn't bucket name. You should consider to distinguish to bucket and the key to build that complex sub-folder path. For that purpose there is keyExpression option with similar functionality to resolve the key in bucket against requestMessage.