features of J2EE application servers
Hi,
i need help with the following question. Any idea.
1. Selection of appropriate Technology
For each of the following requirements:
a: An international banking application needs to subscribe to a currency service so that it can be notified whenever there is a change to the current exchange rate.
b: An electronic shopping application needs to Keep track of the items in an anonymous user's shopping cart prior to confirming the purchase
c: A warehouse inventory application needs to keep track of how many of each item are currently stored in the warehouse.
d: A remote java application client needs to access and update information involving bank accounts and customers as a single transaction.
e: A servlet needs to access and update information involving bank accounts and customers as a single transaction.
State which of the following kinds of EJB would be most appropriate:
(i) a stateless session bean
(ii) a stateful session bean
(iii) an entity bean
(iv) a message-driven bean
2. Container features
J2EE application servers often support some or all of the following features
a: hot deployment
b: load balancing
c: clean shutdown
d: farming
For each one, state what would have to done to achieve a similar effect in the absence of the feature, and whether this would merely be extra work or if the effect would be inferior in some way
3: Application partitioning:
An application is to be partitioned into several tiers:
i: a web browser using forms with javascript code
ii: servlets
iii: a session facade using stateless session beans
iv: entity beans
v: a DBMS
in which tier would it be best to place:
a: code to check that a bank account balance did not become negative?
b: code to check that a month entered by the user is in the range 1 to 12?
c: code to extract a withdraw amount from a form field
d: code to records an updated bank account balance
e: code to transfer funds from one bank account to another one?
