If the transaction attribute is Required, the container ensures that the enterprise bean's method will always be invoked with a JTA transaction.
If the calling client is associated with a JTA transaction, the enterprise bean method will be invoked in the same transaction context.
However, if a client is not associated with a transaction, the container will automatically begin a new transaction and try to commit the
transaction when the method completes.
If the transaction attribute is Required, the container ensures that the enterprise bean's method will always be invoked with a JTA transaction. If the calling client is associated with a JTA transaction, the enterprise bean method will be invoked in the same transaction context. However, if a client is not associated with a transaction, the container will automatically begin a new transaction and try to commit the transaction when the method completes.