Using @Resource to resolve the fileExtensionWhitelist dependency in ProcompressedArtifactFilter

[danielcolgrove]

Resolves https://github.com/BroadleafCommerce/QA/issues/3237

[phillipuniverse]

@danielcolgrove this does not work and is unsafe to merge in. If you use @Resource here in a filter, starting up with Spring Boot will fail since filters are registered directly with the servlet container, and the servlet container (like Tomcat) will try to inject into the @Resource by doing a JNDI lookup. See #1771 and BroadleafCommerce/BroadleafCommercePrivate#958.

[Jerry77oz]

@phillipuniverse we saw the issue where the change (and reason) why it got changed to @Autowired but the issue we were struggling with was, why was it failing when you were testing but it was working for Casey (Icon).

Casey was booting up with @Resource (on 5.2.3-M6) without exceptions and now that he upgraded to 5.2.3-GA he can't start up because the @Autowired is failing to resolve the List<String>.

[phillipuniverse]

@danielcolgrove did a bit of research here and it seems like this is a common problem with primitive types like this. Random person on the internet from https://tamasgyorfi.net/2014/04/02/spring-injection-with-collections/ suggests to change it to this:

@Value("#{blPrecompressedArtifactFileExtensionWhitelist}")
List<String> fileExtensionWhitelist;

The #{} expression in SpEL means look up a bean named whatever is inside.

The issue seems to be that when you @Autowire a collection, Spring treats that as trying to inject every bean of that type in the generic. So Spring looks for every String that it manages and then tries to filter that list down to the specific name in the @Qualifier. I guess since we don't have any String beans, it fails that it cannot find it. The mismatch is that we have a List<String> bean and it actually looks for a String bean.

Likely that we need to spot-check the other changes that I made in the referenced issues.

[phillipuniverse]

@danielcolgrove @Jerry77oz 1 more thing on this, from the main man Juergen himself: https://jira.spring.io/browse/SPR-12180?focusedCommentId=107840&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-107840

[Jerry77oz]

Juergen has spoken!

This was the only case of List<String> in the PR, all the others were using specific classes with the @Autowired.

[danielcolgrove]

@Jerry77oz These changes worked for Casey. We should be able to merge.

The changes Phillip suggested have been implemented