Objective Java Multiple Choice Questions Part 10

91. If there are too many entities with the EntityManager which of the following should be used?

a.       EntityManager.clear()

b.       EntityManager.delete()

c.       EntityManager.discard()

d.       EntityManager.save()

92.     Purpose of Service Locator pattern

à The Service Locator hides the lookup process's implementation details and complexity from clients.

93. What exception is thrown by EntityManager.find()?.

Returns null

IllegalStateException

IllegalArgumentException

94. What is the XML tag used to set max pool size? 

max-pool-size

95. Concept of MOM?

Ans: client---middleware---server

96. What semantics is used by application server to call a remote interface? -

          RMI

97. Which bean is used to manage interaction between different entity beans?

Session Beans

98. Optimisation of SQL call is present in which EJB?

a.       CMP

b.       BMP

c.       Stateful

d.       Stateless

99.     When does Unrepeatable problem occur?

a.       When one transaction deletes a record and another reads it

b.       When one transaction reads a record and another updates it

c.       None

100. Why entity beans are called transactional resources? (Expln: Cos they access DB for storing data often)

a        Cos they’re used in transactions