Autowired interface null in spring boot-CodePudding

Trying to build a services named AccountService an I don't know why my @Autowired field is null. I tried multiple things like ComponentScan and all the stuff you find on google.

Thank you in advance :)

The class that is being auto wired:

package de.scroll.AccountService.Account;

import org.springframework.data.mongodb.repository.MongoRepository;
import org.springframework.stereotype.Repository;

import java.util.List;
import java.util.Optional;

@Repository
public interface AccountRepository extends MongoRepository<Account, String> {

    public Optional<Account> findById(String id);
    public List<Account> findByEmailaddress(String email);
}

The class in which the the auto wired class should be in use:

package de.scroll.AccountService;

import de.scroll.AccountService.Account.AccountRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;

@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class })
public class AccountServiceApplication {

    @Autowired
    public static AccountRepository repository;

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

        test();
    }

    public static void test() {
        repository.findAll();
    }
}

Error:

Exception in thread "main" java.lang.NullPointerException
    at de.scroll.AccountService.AccountServiceApplication.test(AccountServiceApplication.java:22)
    at de.scroll.AccountService.AccountServiceApplication.main(AccountServiceApplication.java:18)

CodePudding user response：

The field repository is null because you can't inject a bean with @Autowired declared as a static field (see Can you use @Autowired with static fields? for more information).

CodePudding user response：

I have successfully used the @Autowired annotation in Spring Boot MVC app. But on the class I want to use, I use the @Component annotation.

@Component
public class RedshiftService {

....

}

Now I can @Autowired in a Controller class and it works fine:

@Controller
public class BlogController {

    @Autowired
    RedshiftService rs;

....

}