春天不满足的依赖

Question

I want to implement JPA repositories as mentioned here . I think my problem is I want to use some functions from the JPA Repository itself and I @Autorwired it But I'm not completely sure

Error Message:

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'addBothStudentsHandler': Unsatisfied dependency expressed through method 'setMajorRepository' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'majorRepository' defined in io.asiam.tansiq.repositories.MajorRepository defined in @EnableJpaRepositories declared on JpaRepositoriesRegistrar.EnableJpaRepositoriesConfiguration: Cannot create inner bean '(inner bean)#78f146b5' of type [org.springframework.data.repository.core.support.RepositoryFragmentsFactoryBean] while setting bean property 'repositoryFragments'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name '(inner bean)#78f146b5': Invocation of init method failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'customMajorRepositoryImplFragment': Cannot resolve reference to bean 'customMajorRepositoryImpl' while setting constructor argument; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'customMajorRepositoryImpl': Unsatisfied dependency expressed through field 'majorRepository'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'majorRepository': FactoryBean threw exception on object creation; nested exception is java.lang.NullPointerException

What I have tried so far:

1- tried to use setter-based @Autowired instead of field-based (But no change)

2- tried to use @Lazy also nothing changed

**Code: **

CustomMajorRepository.java

public interface CustomMajorRepository {
    void addStudentToMajor(Student student, Major major);
    void increaseMajorLimit(UUID majorId, int amount);
}

CustomMajorRepositoryImpl.java

    private MajorRepository majorRepository;

    public MajorRepository getMajorRepository() {
        return majorRepository;
    }

    @Autowired
    public void setMajorRepository(MajorRepository majorRepository) {
        this.majorRepository = majorRepository;
    }
// rest of implementation details

MajorRepository.java

@Lazy
public interface MajorRepository extends JpaRepository<Major, UUID>, CustomMajorRepository {
}

Answer 1

I think you should use dependency injection via constructor or setter, for example:

private MajorRepository majorRepository;

    public CostumMajorRepositoryImpl(MajorRepository mh) {
        this.majorRepository = mh;
    }

Here is the spring.io article about the setter and constructor injection:

https://spring.io/blog/2007/07/11/setter-injection-versus-constructor-injection-and-the-use-of-required/