将我的UserDetailsS​​ervice的自定义实现（使用Spring Data JPA）添加到Spring Boot应用程序的正确方法是什么？

public class DatabaseUserDetailsService implements UserDetailsService {

    @Inject
    private UserAccountService userAccountService;

    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
        User user = userAccountService.getUserByEmail(username);
        return new MyUserDetails(user);
    }

}


public interface UserRepository extends JpaRepository<User, Long>, JpaSpecificationExecutor<User> {

    public User findByEmail(String email);

}



@Service
public class UserAccountService {

    @Inject
    protected UserRepository userRepository;

    public User getUserByEmail(String email) {
        return userRepository.findByEmail(email);
    }

}


@Configuration
@ComponentScan
@EnableAutoConfiguration
@EnableGlobalMethodSecurity(prePostEnabled = true)
@EnableTransactionManagement
@EnableJpaRepositories(basePackages = "com.sample")
@EntityScan(basePackages = { "com.sample" })
@EnableJpaAuditing(auditorAwareRef = "auditorProvider")
public class Application {

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

    ...

    @Order(SecurityProperties.ACCESS_OVERRIDE_ORDER)
    protected static class ApplicationSecurity extends WebSecurityConfigurerAdapter {

        @Override
        protected void configure(HttpSecurity http) throws Exception {
            http
                .authorizeRequests()
                    .antMatchers("/").hasRole("USER")
                    .and()
                .formLogin()
                    .loginPage("/login")
                    .permitAll()
                    .and()
                .logout()
                    .permitAll();
        }


    }

    @Order(Ordered.HIGHEST_PRECEDENCE + 10)
    protected static class AuthenticationSecurity extends GlobalAuthenticationConfigurerAdapter {

        @Inject
        private UserAccountService userAccountService;

        @Override
        public void init(AuthenticationManagerBuilder auth) throws Exception {
            auth.userDetailsService(userDetailsService());
        }

        @Bean
        public UserDetailsService userDetailsService() {
            return new DatabaseUserDetailsService();
        }

    }

}


@Entity
public class User extends AbstractPersistable<Long> {

    @ManyToMany
    private List<Role> roles = new ArrayList<Role>();

    // getter, setter

}


@Entity
public class Role extends AbstractPersistable<Long> {

    @Column(nullable = false)
    private String authority;

    // getter, setter

}

我无法启动应用程序，因为我得到了（此处为完整异常http://pastebin.com/gM804mvQ）

Caused by: org.hibernate.AnnotationException: Use of @OneToMany or @ManyToMany targeting an unmapped class: com.sample.model.User.roles[com.sample.model.Role]
    at org.hibernate.cfg.annotations.CollectionBinder.bindManyToManySecondPass(CollectionBinder.java:1134)

如果我在配置ApplicationSecurity与auth.jdbcAuthentication().dataSource(dataSource).usersByUsernameQuery("...).authoritiesByUsernameQuery("...")一切工作，包括JPA和Spring数据存储库。