Issue
I tried to upgrade a working application from Spring Boot 2.0.6 to 2.1.2. I had some troubles with tests after this change, but eventually got around that. I can successfully build the application from NetBeans (mvn clean install). However, when I try to run from a command line using mvn spring-boot:run, here is what I get:
APPLICATION FAILED TO START
Description:
The bean 'xxxRepository', defined in null, could not be registered. A bean with that name has already been defined in null and overriding is disabled.
Action:
Consider renaming one of the beans or enabling overriding by setting spring.main.allow-bean-definition-overriding=true
The interesting part is that every time I try to run it, the error is on a different repository, but always with the same message.
It would seem that this has to do with this change:
Bean Overriding
Bean overriding has been disabled by default to prevent a bean being accidentally overridden. If you are relying on overriding, you will need to set spring.main.allow-bean-definition-overriding to true.
Given that it is apparently effecting all my repositories, my guess is that there is a configuration problem somewhere. I can follow the recommended action, but it actually made no difference. The problem is that I don't know what to change in the configuration to get this working again. I'm not even sure what to post that is pertinent to the issue. Any ideas on how to figure this out?
Solution
We ran into this issue upgrading from Spring Boot 2.0.x to 2.1.x.
I could "solve" this issue by allowing bean definition override with spring.main.allow-bean-definition-overriding: true but it felt like hiding the root cause.
In fact bean definition overriding used to hide poor configuration on our side.
After inspecting our @Configuration classes we were scanning packages containing our repositories twice, using @ComponentScan and @EnableJpaRepository on the same packages from different classes : once with filters @ComponentScan.Filter, once without.
Removing the second component scan fixed the issue.
Answered By - Michael Técourt
Answer Checked By - David Goodson (JavaFixing Volunteer)