Content Enricher

The Content Enricher is a Message Translator from Hohpe and Woolf. It calls a producer endpoint and feeds the response into the exchange.

    let route = RouteBuilder::from("timer:tick?period=1000&repeatCount=3")
        .route_id("content-enricher-demo")
        .enrich("direct:enrich-data")
        .to("log:enriched?showBody=true&showCorrelationId=true")
        .build()?;

- id: content-enricher-demo
  from: timer:tick?period=1000&repeatCount=3
  steps:
    - enrich: "direct:enrich-data"
    - to: log:enriched?showBody=true&showCorrelationId=true

- id: enrichment-source
  from: direct:enrich-data
  steps:
    - set_body:
        value: "enriched-value"

The .enrich(uri) step sends the exchange to a producer endpoint and waits for a response. The example routes the call to direct:enrich-data. A second route consumes from that endpoint and supplies the enrichment payload. The two-route pattern keeps the enrichment source out of the main route. Multiple consumers can share the same source.

The EnrichmentStrategy trait decides how the response combines with the original exchange. The default UseEnrichedBody strategy replaces the original body with the response body. It keeps the original headers and properties. It discards the response headers. Write a custom strategy when you need to merge both bodies or preserve the response headers.

The difference from Poll Enrich is the data source. Content Enricher calls an active endpoint that receives a request and returns a response. Poll Enrich reads from a polling consumer that holds passive data. Use Content Enricher to pull data from a service. Use Poll Enrich to read from a file or database.

Per ADR-0001, the step compiles into a Service<Exchange> in the Tower pipeline. The EnrichService calls the producer inside the step and merges the response before the step returns. The processor contract is documented in camel-processor/CONTEXT.md.

Reference: Processor crate · Example source