无法初始化代理 - 调用方法时没有发生Session-com.sun.jdi.InvocationException

Question

我的实体

@Entity
@Table(name = "CATEGORY")
public class Category extends BaseEntity {

  @ManyToOne(optional = true)
  @JoinColumn(name = "PARENT_PK")
  private Category parent;

  @OneToMany(mappedBy = "parent")
  private Set<Category> children = new HashSet<Category>();
} 

    @Test

    final Category category = new Category();
    category.setPk("4321");
    categoryRepository.save(category);

    final Category category1 = new Category();
    category1.setPk("1234");
    category1.setChildren(Collections.singleton(category));
    final Category savedCategory1 =  categoryRepository.save(category1);

直到现在一切看起来还不错，但是当我在test中的下一行做如下

final Category savedCategory2 = categoryRepository.getOne(savedCategory1.getPk());

我在eclipse debug com.sun.jdi.InvocationException occurred invoking method.中看到 而且测试栈跟踪说

org.hibernate.LazyInitializationException: could not initialize proxy - no Session
    at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:165)

我正在使用默认的spring boot，hibernate和h2设置，我没有关于数据源或实体管理器的配置。

import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;

@Transactional
@Repository
public interface CategoryRepository extends BaseRepository<Category, String>{

}
@NoRepositoryBean
public interface BaseRepository<T, PK extends Serializable> extends JpaRepository<T, PK> {
    }