Caching a header from one route to another

[samar-elsayed]

Hi,

I am trying to cache a certain header (CamelCaffeineKey) to use it in another route so I have tried caffeine-cache but I dont seem to be able to make it work, could you please explain to me how to use it / load the cache from the first route to the other route?

[mgubaidullin]

@davsclaus is Caffeine Cache component scope is Route or CamelContext?

[oscerd]

You can bind the cache to registry and re-use the same instance in multiple routes of the context https://camel.apache.org/components/4.0.x/caffeine-cache-component.html#_examples

[davsclaus]

its context scoped (in reality per component), also it creates a default in-memory cache if not specially created as the link from Andrea above.

[mgubaidullin]

Thanks @davsclaus and @oscerd

@samar-elsayed you can not put header directly to Caffeine. Set the data you want to cache to exchange body and then put into caffeine cache. In the second route get data from caffeine (it will be in exchange body) and then setHeader from the body.

- route:
    id: route-cbf4
    nodePrefixId: route-1f7
    from:
      id: from-7856
      uri: kamelet:timer-source
      parameters:
        message: Hello
      steps:
        - setBody:
            id: setBody-eaa0
            expression:
              simple:
                id: simple-3dc1
                expression: ${date:now}
        - to:
            id: to-604c
            uri: caffeine-cache
            parameters:
              cacheName: demo1
              action: PUT
              key: key1
- route:
    id: route-778e
    nodePrefixId: route-289
    from:
      id: from-aedc
      uri: kamelet:timer-source
      parameters:
        message: world
      steps:
        - to:
            id: to-191e
            uri: caffeine-cache
            parameters:
              cacheName: demo1
              action: GET
              key: key1
        - log:
            id: log-d474
            message: ${body}

[samar-elsayed]

Thanks, everyone!
@mgubaidullin I can now get the cached body in the current route from the previous route but there is another thing now.

I want to use that cache inside a processor in the current route and that processor is already handling another incoming json body but because of using the cache component it sets the whole body and deletes the incoming json body (cache component doesnt append to it )

my use case here is for example:
I have one route for authentication and inside that route, I am caching a token.
I have another route that receives a request but I also want to use that cached token inside this route but as a header for the same incoming request without deleting its body

[samar-elsayed]

Hi @mgubaidullin @davsclaus,

Based on my last reply, I have tried to enrich the original body in the current route with the cached token from the previous route with this Aggregation Strategy

import org.apache.camel.AggregationStrategy;
import org.apache.camel.Exchange;

import org.springframework.stereotype.Component;

@Component("Addtoken")
public class Addtoken implements AggregationStrategy {
    @Override
    public Exchange aggregate(Exchange oldExchange, Exchange newExchange) {

        if (oldExchange == null) {
            return newExchange;
        }

        String inquiryReq = oldExchange.getIn().getBody(String.class);
        String cachedToken = newExchange.getIn().getBody(String.class);
        newExchange.getIn().setHeader("Authorization", "Bearer " + cachedToken);
        newExchange.getIn().setHeader("CamelCaffeineAction", "GET");
        newExchange.getIn().setBody(inquiryReq);
        
       
        return newExchange;
    }
}

but it fails with me with:

org.apache.camel.NoSuchHeaderException: No 'CamelCaffeineAction' header available of type: java.lang.Stri
ng. Exchange[]

so please advise if there is a better way to have the cached body as a header along with the original body

Thanks!