URDINESH: Java
Showing posts with label Java. Show all posts
Showing posts with label Java. Show all posts

Saturday, July 11, 2015

JAVA


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Friday, May 23, 2014

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


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Objective Java Multiple Choice Questions Part 9

81. JBoss server capable of hot deploy of services keeping track of dependencies. T/F? –

82.   Which is a consumer in Topic?
  MessageSubscriber

83. Which is a producer in Topic?
MessagePublisher
84. Which of the following is correct?
a.       EntityManager em=context.lookup();
b.       EntityManager em=context.lookup(“persistence”);
c.       EntityManager em=(EntityManager)context.lookup();
d.       EntityManager em=(EntityManager)context.lookup(“persistence”);
e.     EntityManager em=(EntityManager)context.lookup(“java:comp/ejb/entitymanager”); 

85. Why do we not have any activation or passivation in MDB like in session beans?
 as MDB receives messages at any time asynchronously

86.Match annotation with purpose:
@EntityListener- Used for Entity beans call back method.
@ExcludeSuperClassListener – In an inheritance hierarchy, the super class listener is ignored in the subclass
@ExcludeDefaultListener – DefaultListener will be ignored.

87. Which protocol is used for remote calls?
 RMI-IIOP

88. Which declaration of local interface is correct?
There was only one option with @Local annotation.

89. If an object is not found during JNDI lookup what exception is thrown?  NamingException

90. What has replaced entity beans?
a. Persitence API

b. Database API
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Objective Java Multiple Choice Questions Part 8


71. Who is Consumer in Topic..?
       Topic Destruction.
       Topic subscriber
       Topic Messages.
       Topic publisher.
       Topic consumer.

72      @version is used in  beans that change less frequently.
True
false

73.  MDBs are like ______
Stateless beans

74.     A large code regarding bean managed transaction (check for the comments)
The answer is the option “ut=sc.getTransaction(); // to get transaction from sessioncontext”

75. MDBs used which of the annotations
a.       Postconstruct
b.       Predestroy
     @Resource @MessageDriven

76. Select one of the options dat best describes Entity beans(so many options with large codes will be given)
 The answer is mostly “IT’S A POJO CLASS WITH ANNOTATIONS”
77. Diff between stateless and stateful bean:
Stateful can use return values of one method in another but stateless cant do it

78.     Which is not a valid bean state?
a.       Does Not Exist
b.       Ready
c.       Pooled
d.       No State



79. Which is a client of a session bean implementing local interface?
a.       Session,entity and MDB
b.       Stateless bean
c.       Stateful bean
d.       Client class must have a jndi lookup
e.   mdb(could be)

80.     How to convert an MDB from stateless to stateful.
a.      Cannot be done


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Objective Java Multiple Choice Questions Part 7


61.  @Entity
        @Table
Public class entitybean {
}
What will the table name for this snippet?
       Same as the class name (i.e. entitybean)
       Null
       None
       Entity

62.  For which option use of EJB not preferred
       Fast processiong
       Transacion processing
       Security maintenance
       Content presentation

63 . EJBHomeFactory pattern is used for
       EJBHome implementation dynamically
       Satatic home obj lookups
       Catching EJBHome Objects
       Factory of EJBHome obj catched for future ref

64.  SELECT ac FROM acct AS ac WHERE id in(1,2)
       Selects id at position 1
       Selects id at position 2
       Selects id at position 1 or postion 2

65.  Default value of @Entity
       CMP
       BMP
       Entity

66. 17. Messages uses ___ protocol and RMI uses ____  protocol
       TCP and RMI-IIOP
       TCP/IP and RMI-IIOP
       RMI and TCP
       RMI-IIOP and TCP


67. How to limit flush to only after the execution is complete
       setFlushMode(FlushModeType.COMMIT)
       setFlush(FlushModeType.COMMIT)
       None

68.  Methods of a MDB interface
       ejbCreate() and setMessageDrivenContext()
       ejbRemove() and setMessageDrivenContext()
       ejbactivate() and setMessageDrivenContext()
       ejbpassivate() and setMessageDrivenContext()

69.  What type of bean can be used for records that are read and updated frequently
       BMP
       CMP
       Stateful
       Sateless

70.  SELECT NEW ejb.30.entity.CustomerRef(c.firstname,c.lastname,c.refreename) FROM C

       Creates a new CustomerRef object and puts the firstname lastname and refreename to it
       Illegal
       Null
       Returns a collection of CustomerRef, which contains first name, lastname and refreename of all rows –


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Objective Java Multiple Choice Questions Part 6


51.     Remote calls use (CB)
a.       RMI/IIOP
b.       TCP/IP
c.       TCP
d.       IIOP/RMI
e.       RPC

52.     EntityManager reference can be obtained from inside or outside of EJB container
a.       True
b.       False

53.     Which of the following does not raise an exception when a method is not called from within a txn
a.       REQUIRED
b.       REQUIRES_NEW
c.       NEVER
d.       SUPPORTS
e.       NOT_SUPPORTED

54.     EntityManager can flush before query ends
a.       True
b.       False

55.     Select object(p) from Player p
When findAll method is implemented in LocalPlayerHomeInterface the query returns objects of type
i.        Player
ii.       LocalPlayer
a.       i
b.       ii
c.       i & ii

56.  Exception that occur when there is no JNDI lookup match
       BindingException
       NamedDoesNotExsistExption
       NullPointerException
       DoesNotExsistNamedException

57. Property not annotated but serialized is mapped to column using
       @Embedded
       @embeddable
       @basic
       @Serialized

58. Design pattern for Read only
       FastReader
       AbstractFactory
       Fastline Reader
       Singleton

59. MessageListener class is
       Has one method
       Is a marked interface
       Has 2  methods

60. Coarse grained EJB are
       Fast
       Slow
       Difficult to maintain
       Serializable


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Objective Java Multiple Choice Questions Part 5


41.     Select c.name , a.address from customer c left outer join address a
The above query will fetch
i.        Customers without address
ii.       Customers with address
Which are valid ?(d)
a.       i
b.       ii
c.       both
d.       none


42.     In publish / subscribe messaging (CB)
a.       There can be many receivers
b.       The receiver need not stay connected

43.     Which of the following are not generator types (CB)
a.       TABLE
b.       NULL
c.       IDENTITY
d.       ENTITY
e. none

44.     Java objects mapped to relational DB
a.       ORM
b.       JPA
c.       Persistence
d.       Entity

45.     Which method must be implemented in CMP
a.       ejbCreate()
b.       atleast one ejbFindXXX()

46.     MessageListener  has
a.       Has only one method
b.       Has one method
c.       Hes two methods
d.       Methods can be added
e.       Marker interface

47.     Which of the following is valid declaration of remote interface
a.       @Remote
b.       remote

48.     select object(a) from customer c where c.i in (1,2)
the query fetches records for which
a.       i is in position 1
b.       i is in position 2
c.       i is either in position 1 0r 2
d.       none

49.     which for the foll is specified while converting java.util.Date to native SQL type
a.       java.persistence.DateType
b.       java.persistence.TemporalType
c.       java.persistence.SysDateType
d.       java.persistence.CalenderType

50.     Isolation levels can be specified by
a.       Deployment descriptor
b.       Annotation

C.       None
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Objective Java Multiple Choice Questions Part 4

31.     Remote interface call by container is
a.       Remote / local based on container
b.       Flexible to make remote call as network call
c.       Always network call
d.       Local call

32.     EJB QL must have(CB)
a.       Select and from
b.       Select and where
c.       Select , from and where
d.       Based on DB schema
e.   can accept parameters(could be)

33.     Attribute that helps to create a new txn using the existing txn
a.       Supports
b.       Not supported
c.       Required
d.       Requires new
e.       Never

34.     Isolation level for removing dirty reads, phantom and repeated reads
a.       TRANSACTION_COMMITTED
b.       Serializable

35.     Which of the following is used when a stateful bean calls a stateless bean from the same container
a.       Local
b.       Remote
c.       Any

36.     MDB is
a.       Stateful bean
b.       Stateless session bean

37.     Deployment descriptor in EJB 3.0 (CB)
a.       Same as 2.0
b.       Not needed as annotations are used
c.       Must be used when necessary

38.     Primary key denoted using
a.       @Id

39.     Jboss detects code changes, deploys those files……
a.       True
b.       False

40.     Which of the following is not used to transform a POJO – entity

i.        DAO
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Objective Java Multiple Choice Questions Part 3

21.     Not a txn attribute
a.       Support
b.       Supports
c.       Supporting
d.       Supported
e.       None

22.     Cache-idle-timeout-seconds means
a.       Application turns off caching after timeout
b.       Idle beans are destroyed from memory after timeout
c.       Idle beans are passivated after timeout

23.     Advantages of messaging (CB)
a.       Synchronous
b.       Decoupling
c.       Reliability
d.       Multiple sender & receiver
e.       All

24.     JANE,JAYME,ANN
Select C from Customer where name like ‘_A%E%’
The query returns :
a.       None
b.       JAYME
c.       JANE
d.       ANN

25.     EJB QL used for (CB)
a.       Finder methods
b.       Select methods
c.       Create methods
d.       Home business methods

26.     Why client txn is not advisable in EJB
a.       Decreases speed
b.       Small granularity
c.       DB locks
d.       Should be used


27.     Advantages of using session bean for calling entity beans (CB)
a.       BMP
b.       No dependency injection
c.       CMP
d.       Dependency injection

28.     Which bean is best in performance
a.       Stateful
b.       BMP
c.       CMP
d.       MDB

29.     Session bean / entity bean throws __________ exception and MDB throws ______ exception
a.       Remote,remote
b.       No exception,RMI
c.       RMI,remote
d.       Remote,no exception

30.     Authentication of credit card when swiped is done by
a.       Stateless
b.       Steteful
c.       Entity
d.    Stateless + MDB

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Objective Java Multiple Choice Questions Part 2

11.     “More persistence involving relational database “
a.       BMP
b.       Stateful
c.       Stateless
d.       CMP

12.     Transactions can be controlled by (CB)
a.       Lazy loading
b.       Turning off auto-comit
c.       TX_REQUIRED
d.       Cannot be controlled completely

13.     Which of the following is implemented in EJB when you want full control over transaction
a.       Management API
b.       Leave it to the container
c.       JTA API
d.       JDBC API

14.     Select Object (A) from Customer As A
Select C From Customer A
The above two are equivalent
a.       True
b.       False (not sure)

15.     In container managed txn the attributes are defined through (CB)
a.       Dependency Injection
b.       Annotations
c.       Deployment descriptor

16.     MDB interface extends
a.       Javax.ejb.SessionInterface
b.       Javax.ejb.StatefulInterface
c.       Javax.ejb.StatelessInterface
d.       Javax.ejb.EnterpriseInterface

17.     No large granularity by(verify)
a.       Stateless SB(sl - ans)
b.       Multiple java classes
c.       Multiple DB tables
d.       Business methods and encapsulating business rules

18.     Persistence is achieved through
a.       Transaction models
b.       Java object serialization & ORM
c.       ORM
d.       Java object serialization

19.     EJB access data rows with no business logic in them
a.       True
b.       False

20.     Entities are remotely accessible
a.       True
b.       False


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