EJB 3.0 has specified following attributes of transactions which EJB containers implement:
REQUIRED - Indicates that business method has to be executed within transaction otherwise a new transaction will be started for that method.
REQUIRES_NEW - Indicates that a new transaction is to be started for the business method.
SUPPORTS - Indicates that business method will execute as part of transaction.
NOT_SUPPORTED - Indicates that business method should not be executed as part of transaction.
MANDATORY - Indicates that business method will execute as part of transaction otherwise exception will be thrown.
NEVER - Indicates if business method executes as part of transaction then an exception will be thrown.