CAMEL-23220: Added support for idempotent consumption in the camel-at…

[MimerPlusPlus]

Camel-atom component.

The fix support idempotency with a plugable strategy for recognizing already seen atom entries. Them component defaults to idempotent consumption, as it did in versions up to 3.16.

It is a proposed fix for CAMEL-23220.

The functionality has been discussed on Zulip chat: #camel > Camel-atom no longer only send entries only once

Description

Target

• I checked that the commit is targeting the correct branch (Camel 4 uses the main branch)

Tracking

• If this is a large change, bug fix, or code improvement, I checked there is a JIRA issue filed for the change (usually before you start working on it).

Apache Camel coding standards and style

• I checked that each commit in the pull request has a meaningful subject line and body.

• I have run mvn clean install -DskipTests locally from root folder and I have committed all auto-generated changes.

[gnodet]

Review — Claude Code on behalf of Guillaume Nodet

Verdict: REQUEST CHANGES

Good feature idea, but there are design issues that should be addressed before merging.

1. Thread safety in ItemUpdatedIdempotentStrategy (Medium)

The contains() + add() pattern is not atomic. If multiple threads process entries concurrently, two threads could both pass contains() for the same key and both process the entry.

Fix: Use IdempotentRepository.add() directly — it returns boolean indicating whether the entry was new, and is typically atomic. Avoid the check-then-act pattern.

2. Hardcoded MemoryIdempotentRepository (Medium)

The consumer always creates a new MemoryIdempotentRepository. Users cannot provide their own IdempotentRepository (e.g., FileIdempotentRepository or JpaMessageIdRepository for persistence across restarts).

Fix: Add a @UriParam for idempotentRepository on the endpoint, defaulting to MemoryIdempotentRepository if not set. This follows the same pattern used by camel-file and other components.

3. Unclear @UriParam description (Low)

idempotentConsume says "Enable idempotent consumption to skip already processed entries" but doesn't clarify what the idempotent key is (entry ID? updated date?). Recommend clarifying.

4. Missing documentation (Low)

The new option should have a brief mention in src/main/docs/atom-component.adoc explaining the feature behavior.

5. No JIRA issue (Low)

Convention is CAMEL-XXXX: ... in commit messages.

[gnodet]

Correction: My review incorrectly stated there was no JIRA issue. The commit title does reference CAMEL-23220. Apologies for the error — the remaining review points (thread safety, hardcoded repository, docs) still apply.

-- Claude Code on behalf of Guillaume Nodet

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[Croway]

Hi @MimerPlusPlus there are the following uncommitted changes

Changes not staged for commit:
  (use "git add <file>..." to update what will be committed)
  (use "git restore <file>..." to discard changes in working directory)
	modified:   catalog/camel-catalog/src/generated/resources/org/apache/camel/catalog/components/atom.json
	modified:   dsl/camel-endpointdsl/src/generated/java/org/apache/camel/builder/endpoint/dsl/AtomEndpointBuilderFactory.java

I'd recommend to cd into catalog and dsl, and mvn clean install -DskipTests both project so that the code is generated