jakarta ee - EJB Transactions in local method-calls

Question

In the following setup, does method B run in a (new) transaction?

An EJB, having two methods, method A and method B

public class MyEJB implements SessionBean
    public void methodA() {
       doImportantStuff();
       methodB();
       doMoreImportantStuff();
    }

    public void methodB() {
       doDatabaseThing();
    }
}

The EJB is container managed, with methodB in requires_new transaction, and method A in required transaction. thus:

<container-transaction id="MethodTransaction_1178709616940">
  <method id="MethodElement_1178709616955">
    <ejb-name>MyName</ejb-name>
    <method-name>*</method-name>
  <trans-attribute>Required</trans-attribute>
  </method>
  <method id="MethodElement_1178709616971">
    <ejb-name>MyName</ejb-name>
    <method-name>methodB</method-name>
  </method>
  <trans-attribute>RequiresNew</trans-attribute>
</container-transaction>

Now let another EJB call methodA with an EJB method call. methodA now runs in an transaction. Will the subsequent call to methodB from methodA run in the same transaction, or does it run in a new transaction? (mind, it's the actual code here. There is no explicit ejb-call to method B)

Answer 1

Your call to methodB() is an ordinary call of a method, not intercepted by the EJB container; at run-time the EJB container will inject a proxy and not an instance of your class, this is the way it intercepts calls and setup the environment before calling your method. If you use this you're calling a method directly and not through the proxy. Hence both methods will use the same transaction, regardless to what is defined in ejb-jar.xml for calls through EJB interfaces.