When the transaction will be committed?

I need some clarification regarding Spring transation. In ClassA I am creating a declaritive transaction. From ClassA I am calling method1() of ClassB. ClassB is having @Transactional(propagation = Propagation.REQUIRED) annotation in classs level. In method1() I am doing a save operation.

My question is, when that data will be committed ? Will it be committed while control will come out from method1()? or in ClassA where we are committing the transaction manually ?.

Code:

ClassA

class ClassA {

    void myMethod() {
        TransactionStatus status = null;
        DefaultTransactionDefinition def =
                new DefaultTransactionDefinition(TransactionDefinition.PROPAGATION_REQUIRES_NEW);
        def.setTimeout(contentFileProcessingConfigBean.getFileCopyTransactionTimeout());
        status = transactionManager.getTransaction(def);

        b.method1();

        if (status != null) {
            transactionManager.commit(status);
        }
    }

}

ClassB

@Transactional(propagation = Propagation.REQUIRED)
class ClassB {

void method1() {

//doing save operation

}
}