Spring Autowiring failing when using Cobertura

Question

When I run Cobertura, it causes the following Spring autowiring error:

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userResource': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.dnb.components.storage.service.UserService com.dnb.components.storage.rest.resource.UserResource.userService; nested exception is java.lang.IllegalArgumentException: Can not set com.dnb.components.storage.service.UserService field com.dnb.components.storage.rest.resource.UserResource.userService to com.sun.proxy.$Proxy56 at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:287)

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As suggested in other related posts, I tried forcing Spring to use CGLIB by changing "proxyTargetClass=true", but this results in a different error:

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userResource': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.dnb.components.storage.service.UserService com.dnb.components.storage.rest.resource.UserResource.userService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: com.dnb.components.storage.repository.UserRepository com.dnb.components.storage.service.UserService.repository; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userRepository': Post-processing of the FactoryBean's object failed; nested exception is org.springframework.aop.framework.AopConfigException: Could not generate CGLIB subclass of class [class com.sun.proxy.$Proxy54]: Common causes of this problem include using a final class or a non-visible class; nested exception is java.lang.IllegalArgumentException: Cannot subclass final class class com.sun.proxy.$Proxy54

This is what the Repository class looks like:

@Transactional
public interface UserRepository extends CrudRepository<User, Long> {

    public User findByCrmId(String crmIdId);
}

Here is the service that gets injected with UserRepository:

@Service
@Transactional
public class UserService extends TraceablePersistenceService<User, UserRepository> {

    @Autowired
    UserRepository repository;

    @Transactional
    public Iterable<User> findAll() {
        return repository.findAll();
    }

    public User findOne(Long id) {
        return repository.findOne(id);
    }
}

Our configuration is in

@Configuration
@EnableTransactionManagement(proxyTargetClass=true)
@EnableJpaRepositories(basePackages = {"com.dnb.components.storage.repository"})
@Profile("inmemory")
public class InMemoryStandaloneStorageConfig extends BasicJpaStorageConfig {

....

(omitted for brevity)

UserResource.java:

@Component
@Path(UserResource.uri)
public class UserResource extends AbstractResource {
    public final static String uri = BASE_URI + "/users";

    @Override
    public String getURI() {
        return BASE_URI + uri;
    }

    @Autowired
    private UserService userService;

...

It seems that the Spring Data JPA generated Repository class cannot be proxied either way without screwing up the auto-wiring.

Is there a fix for this? Is it even a good idea to annotate Repository methods with @Transactional? Should the annotation be at the service level only?

Answer 1

usually, we do not inject concrete classes but we inject interfaces. this is my suggestion.

a. refactor UserService to UserServiceImpl class

b. create UserService interface

c. UserServiceImpl implements UserService

d. add "findAll" and "findOne" method declaration to UserService interface