I have created my own library and it has some code like this

package com.example.demo.service;

@Slf4j
@Service
@RequiredArgsConstructor
public final class MyCustomService {
...
}

package com.example.demo.config;

@Configuration
@ComponentScan(basePackages = "com.example.demo")
public class MyCustomConfig {
}

And I have pushed this library to artifact. Now in another app I am importing the above library in gradle and I am trying to use MyCustomService class but its not working and saying that a bean of type MyCustomService is not available. To make it work I added the below line in "consuming" app and now its working as expected.

@Configuration
@Import(MyCustomConfig.class)
public class AppConfig {}

But is there a way to include a library(my custom library) and then it should automatically register required beans and then work automatically without me having to import MyCustomConfig class again kinda like how other Spring libraries work(all we have to do is just include those deps in build.gradle).

I have created my own library and it has some code like this

package com.example.demo.service;

@Slf4j
@Service
@RequiredArgsConstructor
public final class MyCustomService {
...
}

package com.example.demo.config;

@Configuration
@ComponentScan(basePackages = "com.example.demo")
public class MyCustomConfig {
}

And I have pushed this library to artifact. Now in another app I am importing the above library in gradle and I am trying to use MyCustomService class but its not working and saying that a bean of type MyCustomService is not available. To make it work I added the below line in "consuming" app and now its working as expected.

@Configuration
@Import(MyCustomConfig.class)
public class AppConfig {}

But is there a way to include a library(my custom library) and then it should automatically register required beans and then work automatically without me having to import MyCustomConfig class again kinda like how other Spring libraries work(all we have to do is just include those deps in build.gradle).

• java
• spring
• spring-boot
• autowired
• component-scan

• 1 This might be worth having a look at: docs.spring.io/spring-boot/reference/features/… – Roar S. Commented Feb 4 at 22:03
• I would caution against this - the autoconfiguration of beans made sense for Spring Boot to allow for preconfigured, ready to go webservers and such and this only works because Spring is so popular so most developers now what to look for. Your custom library will leave some poor developer very confused in the future. If I were I would create a library, but still create Configuration classes in client projects. Or define bean configuration in the library but manually import it into client project so it makes sense where the beans are coming from – asgarov1 Commented Feb 5 at 11:35

1 Answer 1

If you use Spring Boot 2:

• Create the file src/main/resources/META-INF/spring.factories in your library.
• Add a key .springframework.boot.autoconfigure.EnableAutoConfiguration with a value consisting of fully qualified class names of your auto-configuration classes, separated by commas.
• In your case the file content has to be .springframework.boot.autoconfigure.EnableAutoConfiguration=package com.example.demo.config.MyCustomConfig.

If you use Spring Boot 3 (to be more precise >2.7):

• Create the file src/main/resources/META-INF/spring/.springframework.boot.autoconfigure.AutoConfiguration.imports in your library.
• List the fully qualified names of your auto-configuration classes in this file, placing each class on a separate line.
• In your case the file content has to be package.example.demo.config.MyCustomConfig.
• Annotate your configs with @AutoConfiguration (actually I don't do it and everything works, but better to follow what docs say)