java - Spring数据和play框架，spring不创建新事务

Question

在我的项目中，我得到了类别类别(仅重要部分代码):

class Category {
  @LazyCollection(LazyCollectionOption.EXTRA)
  @ManyToMany(mappedBy = "categories", cascade = CascadeType.REMOVE)
  private Set<Entity> entities = new HashSet<Entity>();
  /*.rest of code not necessary.*/
}

还有另一个与多对多相关的类:

class Entity {
  @LazyCollection(LazyCollectionOption.EXTRA)
  @ManyToMany(cascade = CascadeType.REMOVE)
  private Set<Category> categories;
  /*.rest of code not necessary.*/
}

我有一个类别 Controller ，我从中调用方法删除。类声明如下所示:

@Named
@Component
@Singleton
public class Categories extends Controller {

这是我的 Controller 中的方法:

public Result delete(Long id) {
  categoriesService.delete(id);
  return ok();
}

我有这样声明的categoryServiceImpl:

@Named
@Component
@Singleton
public class CategoriesServiceImpl implements CategoriesService {

以及service中没有事务的delete方法:

public void delete(Long id) {
  Category category = findById(id);
  boolean inTransaction = TransactionSynchronizationManager.isActualTransactionActive();

  Logger.info("Am I in transaction" + inTransaction);

  /* Exception while trying to access category.getEntities() */ 
  for(Entity entity : category.getEntities()) {
    entity.getCategories().remove(category);
    entityService.update(entity);
  }

  category.getEntities().clear();
  repo.delete(category);
}

我在服务删除方法中尝试访问category.getEntities()时遇到异常:

LazyInitializationException: failed to lazily initialize a collection of role: models.Category.entities, could not initialize proxy - no Session]

我知道这是因为这个方法中没有事务。但是，当我尝试强制事务到我的服务方法时，如下所示:

@Transactional(propagation = Propagation.MANDATORY)
public void delete(Long id) {

或@Transactional(propagation = Propagation.REQUIRES_NEW)或任何传播枚举，我仍然没有在此方法中获得事务。

我做错了什么？我该如何解决它？无论如何，重构代码、另一种方法或想到的任何方法？

Answer 1

尝试使用

public void delete(Long id) {
   Category category = findById(id);
   Hibernate.initialize(category.brands);
   boolean inTransaction = TransactionSynchronizationManager.isActualTransactionActive();
   //Remaining Code Here

}