[CAMEL-9564] EndpointHelper.resolveReferenceListParameter should not return immutable lists

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.16.1
• Fix Version/s: 2.16.3, 2.17.0
• Component/s: camel-core
• Estimated Complexity: Unknown
• Assignee: Claus Ibsen
• Reporter: Jay mann
• Created: 02/Feb/16 21:27
• Updated: 21/Mar/17 21:33
• Resolved: 03/Feb/16 07:37

Description

EndpointHelper.resolveReferenceListParameter can sometimes return immutable lists, which can cause issues when other components try to add items to those lists.

The fact that other endpoints (like jetty-common JettyHttpComponent [enableCors line 279]) can add other components into the lists can cause hard to track down failures.

Sorry don't have a patch file, but the lines i would fix in EndpointHelper.java would be:

line 350: return Collections.emptyList();

line 360: return Arrays.asList(elements.size())

These should just return ArrayLists.

I know these parameters should optionally be Lists already, and this is a slight performance hit when starting up, but i think it's better than trying to figure out what went wrong when it fails.

My particular scenario was a Jetty endpoint with a filtersRef (with a single Filter - not a list) and then enableCORS=true. The filtersRef returned Arrays.asLIst and then enableCORS tried to add an element into that list and crashed.

Issue Links

• is cloned by: CAMEL-11044 CLONE - EndpointHelper.resolveReferenceListParameter should not return immutable lists