Question

I m 采用Sp/JPA2/hibernate这一代码:

class A {
  @Autowired
  B b;

  @RequestMapping("/test")
  public void test(final HttpServletRequest r1, HttpServletResponse r2) throws ... {

    b.inner();   // Works

    b.outer();   // javax.persistence.TransactionRequiredException: 
                 // no transaction is in progress ... :|
}

@Component
class B {
   @PersistenceContext
   EntityManager em;

   public void outer() { inner(); }

   @Transactional
   public void inner() { em.flush(); }
}

为什么只有当交易间接松散时,才有<条码>内()?

Answer 1

http://static.children.org/children/docs/ 当前/vis/transaction.html#transaction-declarative-annotations

In proxy mode (which is the default), only external method calls coming in through the proxy are intercepted. This means that self-invocation, in effect, a method within the target object calling another method of the target object, will not lead to an actual transaction at runtime even if the invoked method is marked with @Transactional.

如果你预计自雇工作也与交易进行总结,则考虑采用AspectJ模式(见下表)。在这种情况下,首先不会有代理;相反,目标类别将重现(即修改其分法),以便把“交易”变成任何一种方法的操作时间行为。

The @Autowired reference B b (inside class A), is wrapped with a Spring AOP transaction-aware proxy.

当打电话到b.inner(>时,你在交易通知中援引该编码,编号为@Transactional。因此,春天管理的交易已经开始。

When b.outer() is called, it is also on a transaction-aware instance, but it is not @Transactional. Thus a Spring managed transaction is not started.

Once you are inside the invocation of outer() the call to inner() is not going through the transaction-aware proxy, it is being invoked directly. It is the same as this.inner(). Since you are invoking it directly, and not through the proxy, it does not have the Spring transaction-aware semantics.

由于没有开始交易,结果见<代码>《交易查询。

Possible solutions include making the method outer() @Transactional.

   @Transactional
   public void outer() { inner(); }

或使整整整类“<代码>@Transactional。

@Transactional   
@Component
class B {
   @PersistenceContext
   EntityManager em;

Answer 2

The transactional context lasts over the scope of your spring bean s entire lifespan. @Transactional notation has a scope of the entire component and you should annotate your @Component as @Transactional eg

@Transactional
@Component
class B {
    @PersistenceContext 
    EntityManager em;

    public inner() { }
    public outer() { }
}

内部和外部方法应当完成个别的工作单位。如果你需要一些助手,或需要什么是罚款,但要求交易边界的工作单位应当扩大到每一种方法。 See the Spring docs on @transactional

友情链接