Zhixiong Pan wrote:
A Synchronous messaging
B Asynchronous messaging
C You shouldn't be using messaging at all as it's not transactional.
D You could use messaging because it is transactional however it's not advised, as the system would never perform well enough for an instant response.
This is one of the Whizlabs questions and the clue is in the phrasing of the answers.
B is obviously wrong as you would not get an instant response
C is wrong because messaging can be transactional
D is wrong because you have just been told the card validations system is VERY POWERFUL. So the statement that is will "NEVER perform well enough for an instant response" is wrong.
So the process of elimination leaves us A.
Syncronous messaging CAN indeed give an instant response. I think you are confusing messaging with asynchronous messaging (fire and forget).
Regards,
Jason.
Edit: I got 100% in this part of the Part 1 exam. I do actually agree that given a choice you would not use messaging, but many existing systems do use syncronous messaging as their interface. If use session beans had been one of the answers it would have been correct.