second tx in @Transactional REQUIRED breaks the first one?

Question

I am not very clear about the behavior of @Transactional with propagation=REQUIRED. an example I see often referenced on the web is like this:

public void callerMethod() {
     call1();
     call2();
}

@Transactional(propagation=REQUIRED)
public void call1() {
}

@Transactional(propagation=REQUIRED)
public void call2() {
}

what I have read is, that when call2() is invoked, because the propagation policy is REQUIRED, it uses "an existing transaction if available", "since call1() opened a transaction, call2() will continue to use that ".

my question is, when call1() is invoked, doesn't the tx proxy code at the end of call1() (added through Spring's AOP ) close the transaction? if it doesn't, then what is the criterior for it to not close the existing tx ? for example, if I have some calls to a non-transactional method in between:

public void callerMethod() {
     call1();
     call3();
     call2();
}
public void call3() {
}

in this case, does call2() still get invoked within the tx started by call1() ?

anyway, in the first case (where call1() and call2() are invoked back-to-back), if call2() throws a runtimeException, then the whole tx rolls back. This becomes rather unexpected to call1()'s declaration, since it declares that its entire method should either fail together or succeed together, but now all its code succeeded, and yet the tx are rolled back (due to some outside exception in call2()), doesn't this contradict its own declaration?

Thanks Yang

Answer 1

Transaction is commited at the end of method. In order to propagate transaction as you expect call2() needs to be called from the body of call1().