Injecting component method output into component constructor-CodePudding

I have a spring boot app with some repositories (i.e. InMemory, Database) that implement a common interface (IRepository), and a factory for accessing them as below.

public class SomeRepositoryFactory {
    
    public IRepository getRepository(String repoType) {
        if (repoType == "Database") {
            return new DatabaseRepository();
        } else if (repoType == "InMemory") {
            return new InMemoryRepository();
        }
        return null;
    }

}

There is also a service class that has a repository as a dependency

public class SomeService {

    private IRepository repository;

    public SomeService (IRepository repository) {
        this.repository = repository;
    }

}

I managed to wire them fine manually with the following configuration

@Configuration
public class MyConfig {

    @Bean
    public SomeRepositoryFactory someRepositoryFactory() {
        return new SomeRepositoryFactory();
    }

    @Bean
    public IRepository someRepository() {
        return someRepositoryFactory().getRepository("InMemory");
    }

    @Bean
    public SomeService someService() {
        return new SomeService(someRepository());
    }

}

However, I'd like to try use autowiring to accomplish this. In particular, I'm not sure how to inject the service class with a repository that is retrieved from the factory. Ideally I'd like to have some annotation like this

@Component
@inject with SomeRepositoryFactory.getRepository.("InMemory")
public class SomeService {

    private IRepository repository;

    public SomeService (IRepository repository) {
        this.repository = repository;
    }

}

CodePudding user response：

If you have only one bean with an implementation for an interface you simply have inject it like you would any other managed instance. You can use constructor injection, @Autowire, setter injection, etc.

This should simply work:

@Component
public class SomeService {

    private IRepository repository;

    // Constructor injection here, should find the bean from someRepository configuration method
    public SomeService (IRepository repository) {
        this.repository = repository;
    }

}

In case you have multiple implementation for the same interface, you could annotate it the injection with @Qualifier:

@Component
public class SomeService {

    private IRepository repository;

    public SomeService (@Qualifier("someRepository") IRepository repository) {
        this.repository = repository;
    }

}