实体经理最佳做法 [英] Entity manager best practices

问题描述

我想知道哪种方式最适合定义实体经理。我使用的是spring boot
$ b $ case 1）在Spring服务类中创建如下所示的

  @Service 
 @Transactional 
 public class DemoService {
 
 private static final Logger log = LoggerFactory.getLogger（DemoService.class）; 
 
私人EntityManagerFactory emf; 
 
 public void getEntity（）{
 final EntityManager em = emf.createEntityManager（）; 
 
 
 @PersistenceUnit 
 public void setEntityManagerFactory（final EntityManagerFactory emf）{
 this.emf = emf; 
} 
 
} 
  

案例2）定义全局实体经理和分享跨所有服务。

注意：每个服务只反映一个单一的实体定义。

解决方案

注入EntityManager是最简单也是最有效的方式：

  @PersistenceContext（unitName =persistenceUnit）
 private EntityManager entityManager; 
  

• 您不需要设置 EntityManagerFactory ，因为您需要一个事务绑定 EntityManager 。


• 您不需要保存 EntityManager ，因为这将是另一个间接层，您可以简单地模拟 EntityManager 。 / li>
  

I would like to know which way is the best to define entity manager. I am using spring boot

case 1) creating in spring service class like follows

@Service
@Transactional
public class DemoService {

    private static final Logger log = LoggerFactory.getLogger(DemoService.class);

    private EntityManagerFactory emf;

    public void getEntity(){
        final EntityManager em = emf.createEntityManager();
    }

    @PersistenceUnit
    public void setEntityManagerFactory(final EntityManagerFactory emf) {
        this.emf = emf;
    }

}

Case 2.) Define a global entity manager and share it across all services.

Note : Each service only reflects one single Entity definition.

解决方案

Injecting the EntityManager is the simplest and the most effective way to do it:

@PersistenceContext(unitName = "persistenceUnit")
private EntityManager entityManager;

• You don't need to set the EntityManagerFactory, since you need a transaction-bound EntityManager.
• You don't need to hold the EntityManager in a global component, since that would be yet another indirection layer and you can simply mock the EntityManager anyway.

这篇关于实体经理最佳做法的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！