Why I can't import a service or a component from a library in Springboot?

I created a "starter project" that I use for storing common dtos, custom exceptions, and classes and use it as a dependency for all my project so that when I update a class I don't have to update every project.

So I just build the jar and use it in the project that I need those classes like this:

implementation files('../my-library/jar/my-library-1.0.jar')

The issue is thought that when I try to use a service or a component from this library I get an error:

org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.nob234.mylibrary.services.MyService' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {}
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1801) ~[spring-beans-5.3.25.jar:5.3.25]

Here is my service in the library:

@Service
@AllArgsConstructor
public class MyService {
    public String addSomething(String string){
        return string + " something";
    }
}

And here I tried to inject it in another service:

@Service
@AllArgsConstructor
public class AnotherService {

    private final MyService myService;

    public String printHelloSomething() {
      return myService.addSomething("Hello");
    }
}

I thought maybe there is a missing constructor or something, but I think there is an issue with the context of the Spring @Service / @Component annotation. How can I fix this?

Fixed it:

When I included the jar file in my project implementation files('../my-library/jar/my-library-1.0.jar'), the Spring context in my project was not aware of the beans defined in the jar file, so it was not able to find and inject them.

To fix this issue, I made sure that Spring scans the packages in my library for components and creates beans for them with @ComponentScan.

@Configuration
@ComponentScan(basePackages = "com.nob234.mylibrary")
public class MyLibraryConfiguration {
}

@ComponentScan annotation tells Spring to scan the "com.nob234.mylibrary" package and all its sub-packages for components to create beans for.

Then, in the main project, I imported this configuration class:

@Configuration
@Import(MyLibraryConfiguration.class)
public class MyAppConfiguration {
}

This will ensure that Spring scans the packages in the library and creates beans for the components defined in it.

Note: If you're already using a configuration class in your library, you can add the @ComponentScan annotation to that class instead of creating a new configuration class.