Repository autowired returning null - spring-data-jpa

Question

I want to make a application with Spring boot on back-end and Swing on front-end. I need to use a repository autowired on my service class, how to make it when i need to instantiate the service class?
I already tried change the repository to BeanFactory, tried to change the location of the files but i can't escape! I need to instantiate the Service class and autowired doesn't work with this.
I have a Model called Permission.
Repository (PermissionRepository.java):
#Repository
public interface PermissionRepository extends JpaRepository<Permission, Long>{
Optional<Permission> findByDescription(String description);
}
Service (PermissionService.java):
#Autowired
BeanFactory beanFactory;
public List<Permission> loadAll() {
return this.beanFactory.getBean(PermissionRepository.class).findAll();
}
Use (BasicOperations.java):
public static void initialPermission() {
try {
if (new PermissionService().loadAll().isEmpty()) {
//logics
}
} catch(Exception e) {
...
}
}
I expect a List, java.util.List but, the error is a nullPointer on my autowired repository
Stack:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at com.riTrap.service.PermissionService.loadAll(PermissionService.java:20)

Answer 1

You should use autowired instead of new PermissionService. You use loadAll to check if the database contains elements. If the database is big, this approach can damage your application. Suggestion : use count instead
#Service
public class PermissionService {
#Autowired
PermissionRepository permissionRepository;
public List<Permission> loadAll() {
return permissionRepository.findAll();
}
public boolean isEmpty() {
return permissionRepository.count() == 0L;
}
}
If you need to initialize the bean before usage, you can use the constructor :
#Service
public class BasicOperations {
#Autowired
public BasicOperations(PermissionService permissionService){
if(permissionService.isEmpty()){
//DO STUFF
}
}
}