Download file contents and names into a List with Apache Camel FTP - ftp

Question

I would like to download a list of files with name and content in Apache Camel.
Currently I am downloading the file content of all files as byte[] and storing them in a List. I then read the list using a ConsumerTemplate.
This works well. This is my Route:
from(downloadUri)
.aggregate(AggregationStrategies.flexible(byte[].class).accumulateInCollection(
LinkedList.class))
.constant(true)
.completionFromBatchConsumer()
.to("direct:" + this.destinationObjectId);
I get the List of all downloaded file contents as byte[] as desired.
I would like to extend it now so that it downloads the content and the file name of each file. It shall be stored in a pair object:
public class NameContentPair {
private String fileName;
private byte[] fileContent;
public NameContentPair(String fileName, byte[] fileContent) { ... }
}
These pair objects for each downloaded file shall in turn be stored in a List. How can I change or extend my Route to do this?
I tried Camel Converters, but was not able to build them properly into my Route. I always got the Route setup wrong.

Answer 1

I solved this by implementing a custom AggregationStrategy.
It reads the file name and the file content from each Exchange and puts them into a list as a NameContentPair objects. The file content and file name is present in the Exchange's body as a RemoteFile and is read from there.
The general aggregation implementation is based on the example implementation from https://camel.apache.org/components/3.15.x/eips/aggregate-eip.html
The aggregation strategy is then added to the route
from(downloadUri)
.aggregate(new FileContentWithFileNameInListAggregationStrategy())
.constant(true)
.completionFromBatchConsumer()
.to("direct:" + this.destinationObjectId);