Spring Boot 3 Upgrade - Autoconfiguration.imports ignored

Question

I am upgrading an application from Spring Boot 2.6 to 3.1. The application is a modular gradle project and makes use of Spring's autoconfiguration.

There is an application that has dependencies to several modules, all these modules provide their own autoconfiguration via a META-INF/spring.factories class. They point to a configuration class that will initialize the code from that module and setup a respective component scan.

That's been working quite well in Spring Boot 2. As the Update Manual suggests, I have migrated these files to META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports and inserted the individual configurations one per line. The Configuration Class itself is annotated as AutoConfiguration and the Main class has @ImportAutoConfiguration.

However, when I start the application, the Autoconfiguration does not seem to be picked up and I get startup errors about missing beans. I verified 10 times that it's the right filename and referencing to the right classes.

Example cases:

main method in an admin-panel module:

package de.herakles.platform.krakenadminpanel;

// import

@SpringBootApplication
@EnableWebMvc
@ImportAutoConfiguration
public class KrakenAdminPanel {

    public static void main(String[] args) {
        SpringApplication.run(KrakenAdminPanel.class, args);
    }

}

there's a gradle dependency on a module called platform-dialect which contains a bean of type SupplierService.

in the module platform-dialect I have this file: platform-dialect/src/main/resources/META-INF/spring /org.springframework.boot.autoconfigure.AutoConfiguration.imports

containing exactly this line:

de.herakles.platform.kraken.platformdialect.KrakenPlatformDialectConfiguration

and the configuration class looks like this:

package de.herakles.platform.kraken.platformdialect;

//imports 

@AutoConfiguration
@EnableJpaRepositories(basePackages = "de.herakles")
@EntityScan(basePackages = "de.herakles")
@ComponentScan(basePackageClasses = KrakenPlatformDialectConfiguration.class)
public class KrakenPlatformDialectConfiguration {

}

In that module, there's a de.herakles.platform.kraken.platformdialect.supplier.SupplierService that is annotated as @Service and should be picked up by the component scan (it did prior to the upgrade). However the error message I am getting is:

Parameter 0 of constructor in de.herakles.platform.krakenadminpanel.dataengineering.VariantController required a bean of type 'de.herakles.platform.kraken.platformdialect.supplier.SupplierService' that could not be found.

I am really struggling - tried all suggestions I could find with nothing working. I am also lacking any indication for how to debug the problem further as the documentation and information on the new autoconfiguration system is not very dense. Therefore I would be very thankful for a solution or a hint for how to debug this issue.

Thanks Matthias

Answer 1

The Issue was in the Gradle Build: Although the individual jars contained the new AutoConfiguration.imports file, these jars were not put in the uber jar created by the spring boot plugin - there were still old versions in there without the AutoConfiguration.imports.

Cleaning all build folders solved the problem.