Jboss EAP 7 CDI JTA @交易记录

Question

I am struggling to understand how I am supposed to deal with JTA and CDI running on a Jboss EAP 7 instance. I can get a transaction manually by injecting a UserTransaction object coming from the container but when I annotate the method with the @Transactional I get an exception regarding no transaction available.... My question is. Is there any config missing? I read briefly that maybe I should create an interceptor myself in order to make it work, but I haven't found any consistent example...

Answer 1

In a default JEE container-managed environment, only enterprise beans (usually @Stateless beans are used) are transactional. Once you enter such a bean from outside, the transaction will be opened. With the @javax.transaction.Transactional annotation you can control the behavior of the transactions, but this is not necessary in default case.

Example bean:

@Stateless
public MyBean {
   public void withinTransaction() {
     System.out.println("i'm running within a transaction");
   }
   @Transactional(TxType.NOT_SUPPORTED)
   public void outsideTransaction() {
     System.out.println("no transaction available...");
   }
}

• If you call MyBean.withinTransaction from a Servlet (eg via REST), a new transaction is created (if not already present).
• If you call MyBean.outsideTransaction , no transaction will be created.
• If you call this.outsideTransaction() from withinTransaction , you will still have the transaction available in outsideTransaction (because the interceptors are only bound to the bean boundaries)
• If you call this.withinTransaction() from outsideTransaction no new transaction is created (because the interceptors are only bound to the bean boundaries)
• If outsideTransaction would be part of a second bean AnotherBean , which @Inject s MyBean , and you call MyBean.withinTransaction , then a new transaction will be created (if not already present). Because you cross bean boundaries between AnotherBean.outsideTransaction and MyBean.withinTransaction .