Resource bundles defined in multiple modules are not merged

[LingCai2001]

I found a problem loading the internationalized resource file. When I need to load international resource files in multiple jar packages, org.springframework.boot.autoconfiguration.context.MessageSourceAutoConfiguration, which is automatically assembled by springboot, can't be loaded for me. I think it's an error because of module reuse in development; What do you say?
Remarks:
SpringBootVersion: 2.5.0

[LingCai2001]

I hope the government can fix the problem and release a new version of SpringBoot as soon as possible. Thank you.

[snicoll]

@LingCai2001 sorry but I am not sure I understood the problem you're describing. Can you please share a small sample that we can run ourselves (no screenshot or code in text please)? You can do so by attaching a zip to this issue or sharing a link to a GitHub repo. Thank you!

[LingCai2001]

BugTest.zip
@snicoll For detailed bug recurrence, please refer to the description tag of Maven's parent pom.xml. Thank you!

[snicoll]

@LingCai2001 thanks for the feedback and the samples. I understand what you're trying to do now.

The reference documentation states that:

Spring Boot looks for the presence of a messages resource bundle at the root of the classpath.

There's no such thing as merging multiple resource bundle files in the classpath. If you remove the resource bundle in your a module and restart you'll notice that http://localhost:8080/b works now, but http://localhost:8080/a does not. We can't really offer that feature: in your case the keys in the files were disjoint but what happens if we have the same key in more than one file?

Having said all of that, I was a bit surprised that it wasn't more prominent in the documentation. @jhoeller, what do you think? Have I missed something?

[LingCai2001]

@snicoll Thank you. I see what you mean; My suggestion is that you can extend one more class to merge resource packages in multiple projects.

[spring-projects-issues]

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[snicoll]

@jhoeller and I discussed and we have no intention of supporting the use case you've described as we're delegating to ResourceBundle for this. We agree that making it a bit more explicit in the doc is a good idea so I've opened spring-projects/spring-framework#27038.