Assuming aMethod, bMethod, cMethod are methods of interface A, their transaction attributes are
REQUIRED, SUPPORTS, and REQUIRES_NEW respectively.
why,aMethod's transaction attribute is REQUIRED ?
If the bean class has superclasses, the following additional rules apply.
• A transaction attribute specified on a superclass S applies to the business methods defined by S.
If a class-level transaction attribute is not specified on S, it is equivalent to specification of
TransactionAttribute(REQUIRED) on S.
• A transaction attribute may be specified on a business method M defined by class S to override
for method M the transaction attribute value explicitly or implicitly specified on the class S.
• If a method M of class S overrides a business method defined by a superclass of S, the transaction
attribute of M is determined by the above rules as applied to class S.