Spring Boot Annotation @Autowired of Service fails

Question

I\'m trying to use @Autowired annotation for a Service class in Spring Boot application, but it keeps throwing No qualifying bean of type exception. Ho

Answer 1

You are using two ways to build a Spring's bean. You just need to use one of them.

1. @Service over the POJO

    @Service
    public class SampleService
   

2. @Bean in the configuration class which must be annotated with @Configuration

    @Bean
    public SampleService sampleService(){
        return new SampleService();
    }
   

@Autowired is resolved by class type then @Bean(name="sampleService") is not needed is you have only one bean with that class type.

EDIT 01

package com.example

@SpringBootApplication
public class Application implements CommandLineRunner {

    public static void main(String... args) {
        SpringApplication.run(Application.class);
    }

    @Autowired
    private UserRepository userRepository;

    @Autowired
    private UserService userService;

    @Override
    public void run(String... strings) throws Exception {
        System.out.println("repo " + userRepository);
        System.out.println("serv " + userService);
    }
}

package com.example.config

@Configuration
public class AppConfig {

    @Bean
    public UserRepository userRepository() {
        System.out.println("repo from bean");
        return new UserRepository();
    }

    @Bean
    public UserService userService() {
        System.out.println("ser from bean");
        return new UserService();
    }
}

package com.example.repository

@Service
public class UserRepository {

    @PostConstruct
    public void init() {
        System.out.println("repo from @service");
    }
}

package com.example.service

@Service
public class UserService {

    @PostConstruct
    public void init() {
        System.out.println("service from @service");
    }

}

Using this code you can comment the AppConfig class and then you will see how UserRepository and UserService are autowired. After that comment @Service in each class and un-comment AppConfig and classes will be autowired too.