[CAMEL-6543] provide a way to expose common header names, types and payload types for endpoints

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Delivered
• Fix Version/s: 3.x
• Estimated Complexity: Unknown
• Assignee: Unassigned
• Reporter: James Strachan
• Created: 12/Jul/13 10:57
• Updated: 09/Aug/23 09:28
• Resolved: 09/Aug/23 09:28

Description

Given a configuration of an Endpoint, it'd be nice if there was a way for endpoints to expose what a consumer will receive up front (at design time, before it actually runs), in terms of headers (their name & types) and the payload type.

Most of this is documented on the wiki in places already - its useful stuff to konw; but there's no way to introspect an endpoint and know this (so we can, for example, visualise the things exposed by an endpoint - or provide better validation of what can connect to what, what will work or fail; what type conversions could be done after consuming from an endpoint, what headers are available by default in expression languages and so forth.

I guess other steps in a camel flow can change this data too (e.g. adding/removing headers, changing the payload value).

But as a start - and endpoint consumer specific plugin would be great.

e.g. maybe we can add a new method to ComponentConfiguration which allows endpoints to return the header/payload metadata (if its known)
https://cwiki.apache.org/confluence/display/CAMEL/ComponentConfiguration

We could maybe add some annotations, metadata or code which could then be introspected by the generated endpoint documentation:
https://cwiki.apache.org/confluence/display/CAMEL/Endpoint+Annotations

afterall we often define constants for the header values already for a component; so it would be easy to add an annotation and have them discovered; its mostly just being able to find all the headers exposed by default (and which are optional I guess) on messages from an endpoint.

Issue Links

• is related to: CAMEL-16628 camel-core - SPI annotations for message headers