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1. Which of the following is EJB System Exception?
1.javax.ejb.ObjectnotFoundException
2. javax.ejb.EJBException3. javax.ejb.DuplicateKeyException
4. javax.ejb.CreateException
2. Possible to iterate multiple times over an iterator (True or false)
3. class Classname {public static void main(String[] args) {
int[][] a1 = {[1,2,3],[4,5,6],[7,8,9,10]};
System.out.print(a1[0][2]+","+a1[1][0]+","+a1[2][1]);
What is output?
Check.. He declared array elements in []..
Compilation Error -> answer
4. class Classname {
public static void main(String[] args) {
int[][] a1 = {{1,2},{3,4,5},{6,7,8,9},{}};for (int i = 0; i < a1.length; i++) {
System.out.print(a1[i].length+",");}}}
What is the result of attempting to compile and run the program?
a.Prints: 2,3,4,0,
b. Prints: 1,2,5,0,c. Compile-time error
d. Run-time error
e. None of the above
5. Is there any method allows to look next element in an iterator(iterator interface)
without advancing the iterator?ans:da. yes,Iterator.peekb. yes, .nextc. no such methodsd. none of the above
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6. Which of the following are valid types of persistent fields in cmp2.0
a. either collection or setb. classes implement java io serializablec. java primitivesd. entity bean local interface
7.. public Class AQuest{
Public void method (object o){
SOP(Object Version)}
Public void method(String S){
SOP(String Version);PSVM(String arg[]){
AQuest q= new AQuest();
q.method(null);
What will be output?a.Object Version
b.String Version
c.compilation fails
d.runtime error
e. compiles but no output
8. This ques is from SCJP book Collection chapter back Ques:
Given:
public static void main(String[] args) {Queue q = new LinkedList();
q.add("Veronica");
q.add("Wallace");
q.add("Duncan");showAll(q);
}
public static void showAll(Queue q) {q.add(new Integer(42));
while (!q.isEmpty())
System.out.print(q.remove() + " ");}
What is the result?
A) Veronica Wallace Duncan
B) Veronica Wallace Duncan 42
C) Duncan Wallace Veronica
D) 42 Duncan Wallace Veronica
E) Compilation fails.F) An exception occurs at runtime.
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9. which the following methods are used in EJBQL Like that.(choose 2)
a) Select method.
a) finder method.
a) Remove method.
a) Business object method.
10. Which of the following produces a compile time error?
a) int arr[][];//1b) int []arr[];//2c) int []arr[];//3None of the above
11. String str =abc;
Str.concat(def);
Str.concat(gh);
SOP(str);
a)compile time error.
b)abcdefgh;
c)abc;
12. No of finally blocks allowed for a try-catch block..a) always 1b). 0 or 1
13. Given six numbers as a[]=1.6,8.9,-9.6,2.0,0.9,3.5
The output is required as 1.6,-9.6,2.0,8.9,0.9Four options with code in it are given
The codes differs in only one line
A sort function like sort(a,0,4) sort(a,0,3) sort(a,1,3) like that
14. A question on core Java with Options
a). All Objects have a length method.
b). Every object has a equals method. (Every object in java also has a hash
code method)
c) Every object has a sort method
15. class Level1Exception extends Exception {}
class Level2Exception extends Level1Exception {}class Level3Exception extends Level2Exception {}
class Purple {
public static void main(String args[]) {
int a,b,c,d,f,g,x;a = b = c = d = f = g = 0;
x = 3;
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try {
try {switch (x) {
case 1: throw new Level1Exception();
case 2: throw new Level2Exception();
case 3: throw new Level3Exception();} a++; }
catch (Level2Exception e) {b++;}
finally {c++;}}
catch (Level1Exception e) { d++;}
catch (Exception e) {f++;}finally {g++;}
System.out.print(a+","+b+","+c+","+d+","+f+","+g);
}}
011001
16. Find the o/pclass A{
psvm(){
try{badMethod();
s.o.p("A");
}catch(Exception e){ s.o.p("B"); }
finally{ s.o.p("C"); }s.o.p("D");
}
static void badMethod(){}
}
options :
a). Compile time error
b). runtime exception
c). ACD
d). AD
17. Find the o/p
class A{
psvm(){
try{badMethod();
s.o.p("A");
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}
catch(Exception e){ s.o.p("B"); }finally{ s.o.p("C"); }
s.o.p("D");
}
static void badMethod(){throw RuntimeException;
}}
options :
a). Compile time error
b). runtime exception
c). ACD
d). AD
18. which is correct?
a). vectors synchronized. Array lists are not (Array lists are also
heterogenous)
b). vectors are heterogeneous array lists are not
19. Class A, Class B extends A, Class C extends B.A method doIt() is implemented in all
classes. How to call doIt() of A with an instance of C.
a). Super.doIt();b.) this.doIt();
Both the options will cause compilation error
20. In EJB 3.0,all are Plain Old Java Objects(POJO)-T/F -> TRUE
21. class Exception1 extends Exception{}
class Exception2 extends Exception1{}
class Exception3extends Exception2{}class Exception4extends Exception3{}
public class Test{
int a,b,c,d,f;int x=5;
try{
switch(x){case 1: throw new Exception1();
case 2: throw new Exception1();
case 3: throw new Exception1();
case 4: throw new Exception1();}
a++;
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}catch(Exception1 e){ b++;}
catch(Exception e){c++}finally{d++}
f++;
}
}System.out.println(a++b+c+d++f);
}
10011
22. package Base;Class Base{
protected void murari();
}
public class Test extends Base.Base{public static void main(String args[]){
Test t= new Test();
t.murari();
}}
What is the output?a) Test class cannot find method in Base classs murari();b) No errors..
Answer: compilation fails
23. class A{
void method() throws ArithmeticException{
}
}
public class C extends A {
void method() throws InterruptedException{
System.out.println("String");}
public static void main(String []args){
}
}
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Which is correct?
a). method() in C class shouldnt throw InterruptedException
b). method() in C class should throw ArithmeticException
24. Which of the following statement is False regarding Tightly Encapsulation?
A). Inner class follows Tightly Encapsulation
b) Anonymous class follows Tightly Encapsulation
Inner classes and anonymous classes in java cannot follow tight
encapsulation. Both of the above options are false.
25. Given a properly prepared String array containing 5 elements which range of results
could a proper invocation of arrays.binarysearch() produce
-6 Through 4
(See the question with option -6 to 4. ( It is is collection question From SCJP 1.5 Book)
26. See the question with options
a). Queuex=new PriorityQueue;
b). LinkedListx=new LinkedList;
. ( It is is collection question From SCJP 1.5 Book)
27. Tasks using a reference to EJBHome
(i) create & remove Session Bean
(ii)get a handle to Session Bean
(iii)create but not remove
28. import java.util.*;class GFC102 {
public static void main (String args[]) {
Object a = new HashSet();System.out.print((a instanceof Set)+",");
System.out.print(a instanceof SortedSet);
}}What is the result of attempting to compile and run the program?
True False
29. import java.util.*;
class GFC102 {
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public static void main (String args[]) {
Object a = new treeSet();System.out.print((a instanceof Set)+",");
System.out.print(a instanceof SortedSet);
}}
What is the result of attempting to compile and run the program?
True True
30. What do enterprise beans use to communicate with the EJB container to get runtimecontext information?
Thejavax.ejb.EJBContextprovided by the container
A JNDI ENC context
A javax.ejb.EJBHomeobject provided by the containerA javax.ejb.EJBMetaDataobject provided by the container
31. The bean class for an entity that uses the EJB 2.0 model of container-managed
persistence:
Must implement java.io.Serializable
Is only used for better integration with popular IDEs
Must be abstract
Must not be abstract
32. At what point, precisely, in the life-cycle is a container-managed entity beanconsidered created?
Immediately prior to the execution of its ejbCreate() method
Immediately after the execution of its ejbCreate() method
After the CMP bean's data has been committed to the underlying persistent datastore
During the execution of its ejbPostCreate() method
33. What is a deployment descriptor?
An XML file format used by the container to learn about the attributes of a bean,
such as transactional characteristics and access controlA method for transporting enterprise beans back and forth between systems
An XML file used by enterprise bean clients to learn about the attributes of a bean, such
as access control and transactional characteristics.A format for bundling enterprise beans for delivery to customers
34. RuntimeException re=null;
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Throw re;
What will be output?
Exception in thread "main" java.lang.NullPointerException
35. cust1= LocalCustomercust1;Cust2= LocalCustomercust2;
If(cust1.IsIdentical(cust2))
{
If(cust2.IsIdentical(cust1)){
S.O.P(true true);
}Else
S.O.P(false true);If(cust1.IsIdentical(cust1)){
S.O.P(true false);
}
}
What is output?
a). true true
b). false true
c). true false... (The question is not clear. But this is the answer for this question)
Title: SCBCD for the java 2 plat form , Enterprise Edition,
Exam: 310-090,
Version: 12-08-05
From the above PDF document
36 Which two can a Bean Provider do if the OnMessage() of a MDB encounter anapplication problem. (In SCBCD PDF see Question No: 41)
Add the application exception to the methods throw clause
Handle the exception in the method; do not throw the exception
Wrap and rethrow the exception as javax.ejb.EJBException
Wrap and rethrow the exception as javax.ejb.RemoteException
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37 Which two statements about session beans with a remote client view are true? (InSCBCD PDF see Question No: 55)
The Bean Provider must implement the get EJBObject method
The Bean Provider must create a class that implements EJBObject
The Bean Provider is not responsible for implementing the handle classes
The Bean Provider must guarantee that an ejbRemove method is
implemented in the bean class
The bean provider is responsible for ensuring that one thread can be executing an
instance at a time
38 Which statement about the EJB 2.0 container in passivation beans is true? (InSCBCD PDF see Question No: 60)
The container must be able to save and restore a beans reference to a
java:comp/env JNDI context across the beans passivation and activation
39 Which transaction attribute may cause ajavax.transaction.TransactionRequiredException to be thrown? (In SCBCD PDFsee Question No: 69)
Mandatory
40 From which method can a Bean Provider legally invoke create() method on abeans own EJB object reference? (In SCBCD PDF see Question No: 82)
ejbPostCreate
41 Which statement is true about purpose of EJB QL? (In SCBCD PDF seeQuestion No: 126)
EJB QL is used to implement the home methods
42 Which statement describes characteristics method permission defined bydeclarative secure?
-> describes which role may call a method
- > describes a role used in method permissions
( for mapping the roles to respective individuals or for
linking security roles)
43 public class CreditCard {
private String cardID;private Integer limit;
public String ownerName;
public void setCardInformation(String cardID,
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String ownerName,
Integer limit) {this.cardID = cardID;
this.ownerName = ownerName;
this.limit = limit;
}}
Which statement is true?
A. The class is fully encapsulated.B. The code demonstrates polymorphism.
C. The ownerName variable breaks encapsulation.
D. The cardID and limit variables break polymorphism.E. The setCardInformation method breaks encapsulation
44 Through which of the following interface does an application create, find and remove
enterprise beans?
1.javax.ejb.EJBHome2. javax.ejb.EJBObject
3. javax.ejb.EntityBean4. javax.rmi.Remote
45 Which of the following is correct about MDB?1. Can execute in client transactional context
2. All messages from the client services by the same MDB
3. MDBs do not have a client visible identity
4. MDB can hold Client Conversation state
46 Which is not a typical action of a catch block?
1. Partial processing of the exception
2. Complete handling,
3. Throwing exceptions4. Rethrow same exception to the calling environment
47 What is the function of isIdentical() method?
Returns true if two stateless session beans are from the same home
Returns false if two stateful session beans are from the same home
48 Which of the following is the requirement of the message driven bean?
Correct Answers:
1) Must implement MessageDrivenBean and MessageListener interface
2) Class must be public
3) Class cannot be abstract or final
4) Must implement 1 onMessage method
5) Must implement one ejbCreate and one ejbRemove method
6) Must -> public constructor with no args
7) Must not define finalize method
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The correct answer should be any one or more of the above options
49 class Classname {
public static void main(String[] args) {
int[][] a1 = {{1,2,3},{4,5,6},{7,8,9,10}};
System.out.print(a1[0][2]+","+a1[1][0]+","+a1[2][1]);}}
What is the result of attempting to compile and run the program?
a. Prints: 3,4,8
b.Prints: 7,2,6
c. Compile-time error
d. Run-time errore. None of the above
50 public class Base {}
class Sub extends Base{}class Sub2 extends Base{}
public class CEx{public static void main (String argv[]){
Base b= new base();
Sub s= (sub)b;}
}
Run Time error
Exception in thread "main" java.lang.ClassCastException: cts.dove.com.A
at cts.dove.com.SuperClass.main(SuperClass.java:21)
51 Private class Base{
Base(){
Int i=100;SOP(i);
}
}PSVM(){
Pri p=new pri();
SOP(i);}
}
What is the output?
a. 200b. 100c. 100 followed by 200
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d. Error52 prototype of default constructor
Public class Test{}
a. test(void)b.
test()c. Public Test()
d. Public Test Void()e. Public Test (void)
53 Which of the following are valid types of persistent fields in cmp2.0
a. either collection or setb. classes implement java io serializablec. java primitivesd. entity bean local interface
54 Which valid delivery modes supported in JMS (any 2)a. Durableb. Permanentc. Non-persistenced. Persistence
http://java.sun.com/j2ee/sdk_1.3/techdocs/api/javax/jms/package-summary.html
55 Class Base{PSVM(string arg[]){
SOP (Hello)Public class Test extends Base{}
What is the output?
a) compilation fails
b) Helloc) Runtime
d) No output
(If the class name is Test.java)
If the class name is Base.java -> compilation fails) The public class Test
must be defined in its own file
56 Application Exceptiona. javax.ejb.NoSuchObjectLocalException
b. javax.ejb.duplicatekey
c. javax.ejb.TransactRolledback
d. javax.ejb.TransactRequiredload.
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57 What must be included in the tag
a. b. c. resources -env-ref>d.
58 J2EE support distributed transaction ans:a
a.True
b.False
59 Collection that maintains unique element is called
a. Hashsetb. LinkedListc. ArrayListd. Vector
60 Which statement is correct?a. Exception in case of VM shutdown,if a try block starts to execute acorresponding finally block must always run to completion
b. Exception in case of VM shutdown,if a try block starts to execute a correspondingfinally block will start to execute.
c. An error that might be thrown in a methiod must be declared as thrown by thatmethod or be handled within that method.
d. Multiple catch can catch same class of exception more than once.e. A try statement must have atleat one catch block.
61 Super(),this()
this serves as a reference to the current object whilst super refers to the super class
of the current object.
This keyword can be used inside the methods and constructors
Recall that the this keyword has two meanings: to denote a reference to the implicit
parameter and to call another constructor of the same class. Likewise, the super
keyword has two meanings: to invoke a superclass method and to invoke a
superclass constructor. When used to invoke constructors, the this and super
keywords are closely related. The constructor calls can only occur as the firststatement in another constructor. The construction parameters are either passed to
another constructor of the same class (this) or a constructor of the superclass
(super).
Either super() or this() should be the first call in a constructor but not both.
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Refer to http://www.informit.com/articles/article.aspx?p=1021579
62 . Bean provider takes if the onMessage method of the MDB encounters an application
exception
If the bean method encounters a runtime exception or error, it should simplypropagate the error from the bean method to the container.
If the bean method performs an operation that results in a checked exception
that the bean method cannot recover, the bean method should throw the
javax.ejb.EJBException that wraps the original exception.
Any other unexpected error conditions should be reported using
javax.ejb.EJBException (javax.ejb.EJBException is a subclass of
java.lang.RuntimeException).
Answers:
1) Handle the exception in the method; do not throw the exception
2) Wrap and rethrow the exception as javax.ejb.EJBException
http://docs.sun.com/app/docs/doc/819-4721/6n6rrfqsj?a=view
63 Java.com prefix access
1) Query Iterators
2) Filters3) Pattern Matching Extensions.
It can access preference information by querying. It can edit preferences and
validate preference values.
http://www.ociweb.com/jnb/jnbAug2006.html
64 CMP entity bean retrieves primary key through
a) EntityContext.getIdentity()
b) EntityContext.getPrimaryKey()
c) Bean.getPrimaryKey()d) Bean.getIIdentity()
65 Both session and entity beans can implement local and remote client views, and
generally the same considerations apply. However, an entity bean must implement a local
client view in what situation?a. When the application uses message-driven beans.
b. When the entity bean is a target of a container-managed relationship.
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c. When the entity bean is located in a different JVM from the client.
d. When the application uses a session bean as a facade to a set of entity beans.
66 If you use container-managed transaction demarcation, you can set a message-driven
bean to participate in a transaction. To ensure that message delivery from the message
destination to the message-driven bean is part of the subsequent transactional work, setthe message-driven beans transaction attribute (in the deployment descriptor) to ans: C
a. NotSupported
b. Mandatory
c. Required
d. Supports
67 Difference between Iterator and ListIterator?
a) Iterator -> Iterate element in the forward direction, List Iterator ->Iterate element in the bi-directional direction.
b)
Iterator -> Iterate element in the bi-directional direction, List Iterator -> Iterateelement in the forward direction.
c) Iterator -> Iterate element in the bi-directional direction, List Iterator -> Iterateelement in the bi-directional direction.
d) None of the above68 class G03 {private String name;}
class G04 {
private String name;public int a1;
public m1(){ sysout(1); }}
class G05 {
private String name;
private int a1;private m2(){ sysout(2); }
}
Which class is tightly encapsulated?
a) G04b) G05c) G06d) None
69 12. public class AccountManager {
13. private Map accountTotals = new HashMap();
14. private int retirementFund;15.
16. public int getBalance(String accountName) {
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17. Integer total = (Integer) accountTotals.get(accountName);
18. if (total == null)19. total = Integer.valueOf(0);
20. return total.intValue();
21. }
23. public void setBalance(String accountName, int amount) {24. accountTotals.put(accountName, Integer.valueOf(amount));
25. } }
This class is to be updated to make use of appropriate generic types, with no changes in
behavior (for better or worse). Which of these steps could be performed? (Choose three.)
A) Replace line 13 with
private Map accountTotals = new HashMap();
B) Replace line 13 with
private Map accountTotals = new HashMap();
C) Replace line 13 withprivate Map accountTotals = new HashMap();
D) Replace lines 1720 withint total = accountTotals.get(accountName);
if (total == null) total = 0;
return total;
E) Replace lines 1720 with
Integer total = accountTotals.get(accountName);
if (total == null) total = 0;
return total;
F) Replace lines 1720 with
return accountTotals.get(accountName);
G) Replace line 24 with
accountTotals.put(accountName, amount);
H) Replace line 24 with
accountTotals.put(accountName, amount.intValue());
Ans : B , E, and G are correct
70 . Class Alpha(){ }
Class Beta extends Alpha{Beta(){
Sysout(Beta);
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}
Public static void main(String args[]){new Alpha();
new Beta();
}
} What is the output when the program is complies?
a) BetaBetab) Betac) Compilation failsd) Run time error
. 71 Question from EJB-QL : I didnt remember the ques correctly but the options given
below are correct...
Which statement are correct like that (choose 2)
a) select object(A.balance) from account A where ABS(A.balance) GT 1000.0b)
select object(A.balance) from account A where ABS(A.balance) > 1000.0c) select object(A.balance) from account A where ABS(A.balance) > 1000.0
d) select object(A.balance) from account A where SQRT(A.balance) >1000.0
72 void test(){Sysout(test);
Print();
}Public void print(){ }
Public static void print() { }
What is the output of the above program?
a) methods are duplicated.b) Test method will call one or more print() method.c) Compilation fails. -> duplicate methods found
73 Which of the following is correct ?
a)
manager
xyz
b)
manager
c)
xyz
74 which the following are used in EJBQL Like that.(choose 2)
a) Select method.
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a) finder method.
a) Remove method.a) Business object method.
75 Class A{
Public static void main(String args[]){
int a1[][] = { {1,2},{2,3,4},{4,5,6,7} );sysout(Print:+ a1.length);
}
}What is the output?
a) Print:0b) Print:3c) Print:5d) Print:4
76 Which of the following are collection classes?
a) vectorb) Hashset
c) Collectiond) Iterator
77 which methods are in both EJBHome and EJBLocalHome?a) void remove(Handle h)
b) void remove(Object PrimaryKey)
c) get EJBMetaData()d) get HomeHandle
78 Class A11{
Public string tostring() { sysout(A11); }
}Class A12{
Public static void main(String args[]){
All a1[] = new A11[1];All a2[][] = new A11[2][];
All a3[][][] = new A11[][][];
a1[0] = new A11();a2[0] = . = 0;
a3[..] = a3[] = a1;
sysout(a3[4][3][..]); ----> they asked to print the value of some 3d array}
}
Options are like this
a) null
b) All
c) compile time error
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d) runtime error
79 Public static void main(String args[]){
try{
if(args.length==0)
return;sysout(args[0]);
}
finally{sysout(Print);
}
}}
I didnt remember the option.. Options are like
a) arrays out of bound exception
b) If no argument is given it prints the stmt in finally block
c) If one argument is given it prints the argument followed by the finallystmt.
d) If one argument is given it prints the argument alone.
80 Question based on try-catch block.
Class A{
Public static void main(String args[]){
int k=0; int i;try{
int i=1/k;}catch{Arithmetic exception ae){ Sysout(1); }
catch(RuntimeException r){ sysout(2); }
catch(Exception e){ sysout(3); }
finally{ sysout(4); }Sysout(5);
}
}What is the output?
a) prints 1,4,5 in the orderb) prints 2,4 in the orderand some other options.
81 int a1[]={1,2}int a2[]={3,4,5}
int a3[]={6,7,8,9}
sop(a1[0][1]+","+a2[1][2]+","+a3[2][3]);
2, 5, 9
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82 Which of the following produces a compile time error?
a) int arr[2][2];//1b) int [3]arr[3];//2c) int [2]arr[3];//3
83 String str =abc;Str.concat(def);
Str.concat(gh);
SOP(str);
a)compile time error.
b)abcdefgh;
c)abc;
84 JNDI Look Up in
a)EJB Context
b)JNDI Context
85 if( string.toString.equals(string))Sop(true)
else
Sop(false)
Ans : True
86 UDDI is ____________
a)Only Registry
b)only repositoryc)both
87 Java 1.5 written in basic or Java or not?
88 Small amount of data is available,rapid access is needed sort is not required.unique
values are not required. Which will you use?
a)Hash Mapb)Tree Set
c)Linked List
d)Array
89 Passivate in EJB
To send the bean from the ready state to the pooled state. ejbPassivate().
It is a container call back method.
The container must be able to save and restore a beans reference to a
java:comp/env JNDI context across the beans passivation and activation
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90 U need to enter 5 Phone Numbers and only two of them are known.the other threenames would be entered and the numbers would be null..
Four options with a long code are given..
Only thing u need to select is the collection i.e Tree Map Hash Table..Hash Map
91 Fail Fast Iterator In Java or not If yes it is related to Synchronized or
Unsynchronized.
fail-fastterm is about Java collections and theirs iteration and modification, which
are not synchronized.
http://www.javafaq.nu/java-article988.html
92 Question on Container Managed Bean Auto Generated Primary Key..
optional flag to use automatic generation of primary key
automatic-pk
optional flag to specify the name of automatic cmp field generate for pk auto-generated
automatic-pk-field-name
If you specify a java.lang.Object as the primary key class type in ,
but do not specify the primary key name in , then the primary key
is auto-generated by the container
93 A question on core Java with Options
Every Object has a length method.
Every object has an equals() method.
(Every java object has an equals() and a hashCode() method)
http://www.ibm.com/developerworks/java/library/j-jtp05273.html
94 Does List collection provide list iterator?
TRUE
(http://java.sun.com/docs/books/tutorial/collections/interfaces/list.html)
95 Questions on pooled bean like which bean can be considered a part of pooled beans..
Their characteristics..
Stateless session beans -> pooled beans
Entity Beans -> pooled beans, cached beans
Stateful session beans -> only cached beans
Message driven beans -> pooled
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http://docs.sun.com/source/819-0084-10/pt_tuningas.html
96 Message driven bean: what methods will it use for passing messages - >
onMessage(javax.jms.Message msg)
97 class Level1Exception extends Exception {}
class Level2Exception extends Level1Exception {}
class Level3Exception extends Level2Exception {}class Purple {
public static void main(String args[]) {
int a,b,c,d,f,g,x;a = b = c = d = f = g = 0;
x = 3;
try {
try {
switch (x) {case 1: throw new Level1Exception();
case 2: throw new Level2Exception();case 3: throw new Level3Exception();
} a++; }
catch (Level2Exception e) {b++;}finally {c++;}
}
catch (Level1Exception e) { d++;}catch (Exception e) {f++;}
finally {g++;}System.out.print(a+","+b+","+c+","+d+","+f+","+g);
}}
What is the result of attempting to compile and run the program?
Prints: 0, 1, 1,0,0,1
98 Should finally block always follow the last catch block..(t/f)
False
99 User defined Exceptions -> Custom Exceptions
User Defined Exceptions (Checked Exceptions)
Class Not Found Exception
Clone Not Supported Exception
AWT Exception
IO Exception
File Not Found Exception
EOF Exception
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Interrupted IO Exception
Run Time Exceptions (Unchecked Exceptions)
Arithmetic Exception
Null Pointer ExceptionIndex Out Of Bounds Exception
No Such Element Exception
100 which methods should not be used by container managed beans
Methods used by container managed beans -> ejbcreate, ejbremove, ejbactivate and
ejbpassivate (for stateful session beans) and setsessioncontext,
setmessagedrivencontext and setentitycontext (for respective beans)
101 T/F Does EJB provides support for nested transactions -> False
102 - The EJB QL question (Its there in questions from sun links)
103 which of the following communications are allowed in EJB
options : point to point
send receivebroadcast receive
Answers: 1) Publish and Subscribe
2) point to point
http://www.ibm.com/developerworks/websphere/library/techarticles/0304_yu/yu1.ht
ml
104 If array contains two elements which are equal then after using Arrays.sort methodindex of elements will get changed.
Answer -> False
http://www.leepoint.net/notes-java/data/arrays/70sorting.html
105 Find the o/p
RunTimeException re = null;
throw re;
ans: Option containing NullPointerException
106 Find the o/p
class A{psvm(){
try{
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badMethod();
s.o.p("A");}
catch(Exception e){ s.o.p("B"); }
finally{ s.o.p("C"); }
s.o.p("D");}
static void badMethod(){}
}
options : Compile time error
runtime exception
ACD
AD
107 Find the o/p
class Base{
void abstract method(){};}
class Child extends base
{//some code dont remember
}
Options: Compile time error
Runs and prints o/p
Ans: abstract method declaration contains {}
108 Find the o/p
Class Base{
Base()
{int i = 1;
s.o.p("i : "+i);
}}
class Child extends Base
{public i;
child(int i)
{
super(i);s.o.p(i);
}
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psvm()
{sop(new Child(5));
}
}
The parent class was not having constructor with 1 argument (integer type).
Compilation error
109 class Base
{
static x=1;Base()
{
x+=1;
}
}class Child extends Base
{Child()
}
Compilation Fails
110 Collection Question where queue was created as followingQueue q = new List();
q.add("A");q.add("B");
q.add("c");
then, there was one method
void method(Queue q){
q.add(new Integer("42"));
}psvm()
{
q.reverse();while(q.hasNext)
{
s.o.p(//code for printing element);}
}
Compilation Fails. Interfaces cannot be instantiated (They have instantiated the List
interface in the above code)
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111 class superclass{
private void method(){}
Class subclass extends superclass{
Public void method(){
}Public static void main(String []a){
subclass s=new subclass();
s.method();}
Which method is invoked ie. method present in superclass or subclass
112 class come{
Public static void main(String []a){
Try{
Int i=0;Int y=5/0;
}catch(Exception e){ }catch(ArithmeticException e){ }
}
}
What will be the output? Compilation Error (Unreachable catch block for
Arithmetic Exception)
113 class base{base(int i){
}
}
Class sub extends base{Sub(){ }
Sub(int i){ }
Public void method(){ }
How to invoke the constructor present in base class from subclass
Calling super(i) from either Sub() or Sub(int i)
114 what are the unique features of List.
It can have duplicates
Positional Access
Search
Iteration (Iterator and List Iterator)
Range-view
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http://java.sun.com/docs/books/tutorial/collections/interfaces/list.html
115 Class Exception1 extends Exception{}
Class Exception2 extends Exception{}
Class test{
p.s.v.m (){
try{
}catch(Exception2 2){}
Catch(Exception1 e){}
Catch(Exception e){}}
Public void method() throws Exception1{
Throw new Exception1 ();
}
}Regarding flow
Compilation Error
116 which of the following st are true?
(a)overriding method must have the same signature as overriddenmethod
(b)overriding method can throw exceptions which are not present inoverridden method
three more options are there
The Overriding method must have the same signature, same arguments
(Argument list and Argument order) and same return type as that of the
overridden method
117 multidimensional arrays listing of elementslike a1[]={2,3}
a2[]={2,3,4}
a3[]={3,4,5,6}a[][]={a1,a2,a3}
then the ques will be like
sop(a[0][1]+","+a[1][2]+","+a[2][3])Then they ask you the output
It can be
compilation error
1316
3,4,6
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118 difference between hashtable and hashmap
Hashtable - > Should not contain null values, It is synchronized.
HashMap - > May contain null values, and is not synchronized
119 which is synchronized---vector and hash table are synchronized. Others are notsynchronized.
120 which collection is best for inserting the value in middle Linked list
Linked List -> Slowest Access and Fastest Insertion
121 which collection is worst for inserting value in middle arraylist
http://java.sun.com/developer/JDCTechTips/2002/tt0910.html
122 Arrays.sort one question ---answer is sort 1, 3
123 Inheritance one theoretical ques like inheritance means has a relationship false
Inheritance means IS-A Relationship
124 Message driven bean needs 2 interfaces i.e. messagedrivenbean and
messagelistener
125 Which i/f provides Slowest/Fastest access to middle element?
Slowest - Linked list
Fastest - Array List
http://java.sun.com/developer/JDCTechTips/2002/tt0910.html
126 Class of exceptions tat is unchecked
Arithmetic,
FileNotFound, -> Checked Exception (File Not Found is a sub-type of IO
Exception)
Runtime,
All
127 class B{
psvm(String args[]) {(s.o.p(Hello);
}
}
Public class T extends B{}a) Compilation fails
b) Hello
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c) Runtime
d) No output (If the file name is T.java)
Compilation fails if the class name is B.java, because the public class T must be
defined in its own type
128 Differences bw ArrayList and vector which is synchronized and asynchronized,
which one contains heterogeneous elements
Array list is not synchronized. Vector is synchronized.
Both Array List and Vector can contain heterogeneous elements.
129 Transactions in EJB ->Nested transactions are not allowed, Parallel transactions
are not allowed, EJB supports transactions for all the bean types. EJB also supports
security. EJB supports distributed transactions and security.
130 What all given below are thrown by throw statementError
Object
Exception
Throwable
Runtime Exception
131 Vector can be deleted by which method:
Delete method
Remove method
132 Session Bean can have zero create method-T/F -> False
133 Class A, Class B extends A, Class C extends B.A method doIt() is present. How to
call doIt() of A with an instance of C.Super.doIt();
this.doIt();
Both the options will cause compilation error
134 if((new Object))(.equals((new Object) and some 2 lines code and asked whetherthis will return true or false.
False
135 A superclass A is defined and a subclass B is defined which extends A and one more
class is defines which extends B.
Is it possible to invoke the method of class A using the object of Class C Using superkeyword.
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False
136 public class C {
void method(String s){
System.out.println("String");
}void method(StringBuffer s){
System.out.println("String Buffer");
}public static void main(String []args){
C c = new C();
c.method(null);}
}
Answer: Compilation error (The method (String) is ambiguous) for type C
137. class A{
void method() throws ArithmeticException{ }}
public class C extends A {
void method()throws InterruptedException{System.out.println("String");
}
public static void main(String []args){ }}
Answer: we should remove interrupted exception
138 class A{
Message msg = new Message();}
public class C extends A {
void method(){System.out.println(?);
}
public static void main(String []args){C c = new C();
c.method();
}}
class Message{
String text = "hello";
}How do you access text in Message class and print in the method() in Class C
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Options:msg.text,super.msg.text.object.super.msg.text
Answer : msg.text and super.msg.text
139 public class C {
public static void main(String []args){String baz = args[3];
System.out.println(baz);
}}
Given the Arguments java test red green blue
Answer:Run time Exception ArrayIndex out of Bounds Exception
140 Differntiate ArrayList and Vector
a) ArrayList is synchronised but vector is not.b) Vector is synchronised but ArrayList is not.
c) Arrays store heterogeneous objects but vector doesnotd) Vector store heterogeneous objects but Arrays doesnot
Answer :B
141 Vector contains Heterogeneous objects. State true or False
Answer:True
142 public class C{public static void main(String []args){
String sad = null;
sad.concat("bha");
sad.concat("rat");System.out.println(sad);
}
}
Answer: RunTime Exception null pointer Exception
143 String sad = "bharat";
sad.concat("bha");sad.concat("rat");
System.out.println(sad);
answer:bharat
144 String sad = "bharat";
String asd = sad.concat("bha");
System.out.println(asd);
Answer:bharatbha
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145 public class C{
public static void main(String []args){if(args.length==0){
sytem.out.println("hi")
return;
System.out.println(args[0]);}
}
Four options are there....CHeck box ...asked to mark two options....
If there is no argument it will print hi
If one argument ...it will print that argument
146 class TestException extends Exception{
}
class FlyingException extends TestException{void method() throws TestException{
}}
public class C{
public static void main(String []args){FlyingException c = new FlyingException();
try {
c.method();} catch (FlyingException e) {
// TODO Auto-generated catch blocke.printStackTrace();
}
}
}
Answer: Compilation Error TestException should present in the Flying
Exception
147 How many Finally blocks can a try-catch block have?
Answer:0 or 1
148 class level1exception extends Exception{ }
class level2exception extends level1exception{ }public class level3exception extends level2exception{
public static void main (String [] args){
int x=2;
int a=b=c=d=f= 0;try{
switch(x) {
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case 1: { throw new level1exception(); }
case 2: { throw new level2exception(); }case 3: { throw new level3exception(); }
}
}catch(level3exception e){ a++; }
catch(level2exception e){ b++; }catch(level1exception e){ c++; }
finally{ d++; }
f++;System.out.println(a+","+b+","+c+","+d+","+f);
}
}
01011
149 public class level3exception{
public static void main (String [] args){Set s = new TreeSet();
s.add("2");s.add("3");
s.add("1");
System.out.println(s);}
}
Answer: [1, 2, 3]
150 Question on Iterator...Check Box which of the following atr true?
1)Iterator is member of Java Collection Framework
2)Iterator is the replacement of Enumeration in Collection Framework.
151 EJB timer objects are like stateless session beans? True or False
152 char c=new char[1],byte b=new byte[1],
float f=new flota[1],object obj=new object[1]sysout(c[1],b[1],f[1],obj[1]);
Array Index Out of Bounds Exception
153 what bean provider should declare in deployment descriptor?
1. Class name -> specifies the fully classified name of the bean class
2. Bean name -> specifies a beans name
3. Transaction type -> Specifies the transaction management type of an EJB
(bean- or container-managed).
http://sarwiki.informatik.hu-berlin.de/Bean_Provider's_Responsibilities
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154 what class should be used for bean to provide programatic security ?
1.EJB metadata context2.client meta data security
An application component provider accesses programmatic security for EJB and
Web components with J2EE platform security APIs.
Javax.ejb.EJBContext -> Answer
http://www.googleperson.wideopen.com/docs/manuals/rhaps/jonas-guide/s1-
security-sec-programmatic.html
155 a collection can refer itself ? true or false
156 methods in EJB home and local home interfaces
EJBHome
getEJBMetaData()
getHomeHandle()
remove(Handle handle)
remove(obj PK)
EJBLocalHome
remove(obj PK)
157 which bean is used to embody business objects
1.enterprise bean
2.entity bean
3.session bean
158 What does the EJB specification architecture define?
A. Transactional componentsB. Distributed object components
C. Server-side components
D. All of the above
159 How can client prepare itself for callbacks from the RMI server?
Extendjava.rmi.server.UnicastRemoteObject
Call UnicastRemoteObject.exportObject()
Either of the above two will work.
160 int []a1={1,2,3}
int[]a2={3,4,5}
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int[]a3={6,7,8,9}
int[][]a={a1,a2,a3}sysout(a[0][1],a[0][2],[0][3])
2, 5, 9
161 class c extends B
B extends A
all implemnts the method doit()then how can we cal the doit() method in A from c
options are like super.doit(),super.this.doit()
Neither of the above options will work.
162. In Test.java
class Base{ public static void main(string args[]){
public void amethod(){System.out.println(Hello);
}
}public class Test extends Base{}
What is the output of the program?The code compiles and runs with out any output
Compilation fails -> (public void amethod())
Runtime error is thrown
The code compiles and prints Hello
163 private class A{//some code here
}
public class B extends A{public static void main(String args[]){
}
}
Compilation Error -> Private Class A
164 valid array declarations
int [] a1[], a2[] ,a3[];
int [][]a1, a2[];
int []a1[];
All the above declarations are valid.
Invalid declaration -> int []a1, []a2; -> some thing like this. The [] in an
array can come either after the identifier or after the type.
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165 class Test{private int cardID;
private int cardNumber;
public String name;
public void setCardID(int cardID){this.cardID=cardID;
}
public int getCardID(){return cardID;
}
public void set cardNumber (int cardNumber){this. cardNumber = cardNumber;
}
public int get cardNumber (){
return cardNumber;
}}
Which of the following statement is true?
The variable name violates the encapsulation
Like that four options are given. I think the above option is correct.
166 four classes are given with some variables and methods. And asked to find which
classes violate the encapsulation.
Class which does not contain private data members (private instance variables) will
violate the Encapsulation -> for example, public String name; This type of
declaration will violate encapsulation.
167 class A{int I=0;
public A(String s){
i=1;}
}
class B extends A{public B(int i){
I=2;
}}
public class C extends B{
public static void main(String args[]){
C c=new C();System.out.println(i);
}
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}
ans: four options are given. But all the options are given. I think it will give
compilation error.
But the options are very close, if it is compilation error also due to which reasonthe error is try to see that also.
Compilation Error
168 class Base{public Integer method(Integer i){
return new Integer(100);
}
public Long method(Long l){
return new Long(200);}
}public class Test{
public static void main(String args[]){
Base b=new Base();b.method(5);
}
}
For this questions I dont remember the options exactly.
Compilation Fails
169 Difference between Vector and Array list
Vector -> Synchronized
Array List -> Not Synchronized
170 class Exception1 extends Exception{}
class Exception2 extends Exception1{}class Exception3extends Exception2{}
class Exception4extends Exception3{}
public class Test{int a,b,c,d,f;
int x=5;
try{
switch(x){case 1: throw new Exception1();
case 2: throw new Exception1();
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case 3: throw new Exception1();
case 4: throw new Exception1();}
a++;
}catch(Exception1 e){ b++;}
catch(Exception e){c++}finally{d++}
f++;
}}
System.out.println(a++b+c+d++f);
}in the above question value of x is 5 it is not matching with any of the cases in
switch.
10011
171 Class Base{
//some code here}
public class Test extends Base{
public static void main(String args[]){// some code here
}
}I dont remember the code exactly. But it is like without compiling the base
class test class can get the functionality of the base class.
True
172 package com.base;class Base{
Protected String name;
// some more code}
package com.Test;
class Test extends Base{
public static void main(String args[]){
// some code here}
}
but in the above code the Base class is not imported in the Test class. The options arevery close. Due to which reason it gives the compilation error.
Remember that compilation error also
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Compilation Error
173 what will happen if catch is not there and only finally is there
Will continue normally or terminate
174 what happens when calling base constructor when u dont have local constructor
The compiler will create a no-argument default constructor only. In order to invoke
a constructor with some arguments inside the base class, a matching constructor
type should be created explicitly in the derived class
175 when a ejb object is in pooled state we need to bring to active state what all methodsneed to call
ejbCreate(), ejbPostCreate() and ejbActivate()
176 equals and hashcodeEquals() returns true -> hashcode() must return true
Equals() returns false-> hashcode() might return false
Hashcode() returns true -> Equals() might return true
Hashcode() returns false -> Equals() must return false
177 bean can use both bmp and cmp at the same time - true or false -> false
CMP and BMP beans can be used in the same application and a bean can be CMP
or BMP, but not both at the same time. They are mutually exclusive.
http://faqs.javabeat.net/ejb/enterprise_java_beans_ejb_interview_questions_4.php
178 message driven bean is stateless or stateful -> stateless
179 how many instances of mdb can run at a time -> many instances can run in parallel
180 vector is heterogenous true or false -> True
181 can tostring used to convert object to string ->True
182 byte[] b=new byte[1];int[] i=new int[1];
long[] l=new long[1];
Object[] o=new Object[1];
System.out.println(b[0]+" "+i[0]+" "+l[0]+" "+o[0]);
Ans: 0 0 0 null
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183 Class which allow bean programmatic security
(i) javax.ejb.EJBContext
(ii) javax.ejb.EJBMetaData
(iii) javax.ejb.Security(iv) javax.ejb.ClientMetaData
Ans: (i)
184 Tasks using a reference to EJBHome
(i) create & remove Session Bean(ii)get a handle to Session Bean
(iii)create but not remove
185 FailFastIterator in Java
(i) No failFastIterator concept in Java(ii)FailFastIterator helps in iterating and conditioning.....
2 more options .. don remember
fail-fastterm is about Java collections and theirs iteration and modification, which
are not synchronized.
http://www.javafaq.nu/java-article988.html
186 Tasks by application assembler
(i)Bind a Resource manage connection factory reference with...(ii) Assign Resource manage connection factory to.....
2 more options .. don remember
To link an enterprise bean reference to a target enterprise bean
187 Session bean Passivation
(i)container cannot remove a bean in passivated state(ii)must call stateless session bean ejbPassivate method b4 moving it to bean pool.
(iii) isIdentical () called for passivation
1 more option .. don remember
Passivation and activation are only for stateful session beans. Not for stateless
session beans.
For entity beans, bean cannot be removed after passivation. Results in orphaned
rows in the database table. The method used is ejbPassivate(). It is a container call
back method.
The container must be able to save and restore a beans reference to a
java:comp/env JNDI context across the beans passivation and activation -> Answer
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188 Locating or using a Session bean's Home Interface (correct stmts)
(i)Client can acquire a handle for bean's Local Home Interface(ii) Acquiring Initial Context required for remote clients
(iii)Once acquired by client, can be used multiple times
(iv)Initial Context must be narrowed b4 used.
189 Which java.util.classes & interfaces support event handling?
(i)EventObject
(ii)EventListener
(iii)Both
(iv)None
http://www.geekinterview.com/question_details/25
190 Valid message models in JMS
(i)send/receive
(ii)broadcast/receive
(iii)publish/subscribe(iv)point-to-point
Ans: (iii) and (iv)
191 EJB timer service used with
(i) CMP
(ii)CMP, BMP, MSD
(iii)MSD
(iv)CMP,BMP
192 Iterator is class
true false
Iterator is an interface
193 String str=null;str.append("RAJ");
str.append("kumar");
s.o.p(str);
Compilation Error -> The method append(String) is undefined for the type String.
In the above code, if append is replaced by concat, then a Null Pointer Exception
will be thrown.
194 Collection will extend Cloneable and Serializable Interface? (T/F) false
195 Diff b/n HashTable and HAsh Map---hashtable is ordered version of hashmap..
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ans:HashTable does not allow null values & it is Synchronized. HashMap allows
one null key and multiple null values in a collection. Hash Map is not synchronized.
196 Hash Set s=new Hash Set();--unordered unsorted.
a) s is instanceOf Set-----true
b) s is instanceOf SortedSet----falseOptions:
1) true false 2) false false like this
197 package mypack;
class C {
C() {System.out.println("Default");
}
C(String i) {
System.out.println(i);
}}
class B extends C {B(String s) {
//super(s);
System.out.println(s);}
B() {
this("1", "2");System.out.println("Mytest");
}B(String s1, String s2) {
this(s1 + s2);
}
}public class A extends B {
public static void main(String[] args) {
B b = new B("Test");}
}
Ans: Default Test
In above ques is Super in class B is not commented then o/p is Test Test
198 An Abstract class can extend a non-abstract class (T/F) ans: True
199 Correct about session beansa) Session beans can be private
b) Session beans can be final -> session bean cannot be final
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c) Session beans allow overloading -> method overloading is allowed in EJB
200 valid array declaration of an array choose three
a) int[] a[],b[];
b) int []a,b[];c) int[] a,b[];
d) int[][] a,b[];
I did't remember the exact options
All the above options are correct
Invalid declaration -> int []a1, []a2; -> some thing like this. The [] in an array can
come either after the identifier or after the type.
201 following are valid collection classes
a) List Bag
b) Hash Mapc) Vector
d) Set List
202 True about arrays (increases or decreases) -> decreases
size of array increases performanceinsertion, deletion time
Increasing the size of an array will decrease its performance.
203 Question on when to use throw and throws
Throws is used along with a method signature to specify that a particular method
may throw an exception. A method signature must declare the type of exceptions
that it is expected to throw in throws clause.
A throw statement specifies a particular exception being thrown.
204 Error error=new Error();
error is instanceOf Exception (T/F)
false
205 package mypack;
class Parent {Parent() {
int i=2;
}
}public class Child extends Parent {
Child(){
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int i=1;
}public static void main(String[] args) {
Child b = new Child();
System.out.println(b.i);
}}
ans: compilation error
206 Which i/f provides Slowest/Fastest access to middle element? Linked list/Array List
Slowest access -> Linked List
Fastest access -> Array List
207 class B{
psvm(String args[]) {
(s.o.p(Hello);
}
}
Public class T extends B{}
a) comp fails
b) Hello
c) Runtime
d) No output
208 Class A{
Public static void main(String args[]){int k=0; int i;
try{
int i=1/k;}catch{Arithmetic exception ae){
Sysout(1);
}
catch(RuntimeException r){sysout(2);
}
catch(Exception e){sysout(3);
}
finally{sysout(4);
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}
Sysout(5);}
}
What is the output?a) prints 1,4,5 in the orderb) prints 2,4 in the order
and some other options.
209 A superclass A is defined and a subclass B is defined which extends A and one more
class is defines which extends B.
Is it possible to invoke the method of class A using the object of Class C Using super
keyword. -> False. It is not possible to invoke.
210 public class C {
public static void main(String []args){
if("String".toString()=="String"){
System.out.println("Equal");
}else{
System.out.println("Not Equal");
}
}
}
Answer: Equal
211 public class C {
void method(String s){
System.out.println("String");
}
void method(StringBuffer s){
System.out.println("String Buffer");
}
public static void main(String []args){
C c = new C();
c.method(null);
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}
}
Answer: Compilation error
212 class A{
void method() throws ArithmeticException{
}
}
public class C extends A {void method()throws InterruptedException{
System.out.println("String");
}
public static void main(String []args){
}
}
Answer: we should remove interrupted exception
213 class A{
Message msg = new Message();
}
public class C extends A {
void method(){
System.out.println(?);
}
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public static void main(String []args){
C c = new C();
c.method();
}
}
class Message{
String text = "hello";
}
How do you access text in Message class and print in the method() in Class C
Options:msg.text, super.msg.text.object, super.msg.text
Answer: msg.text and super.msg.txt
214 In Test.java
class Base{public static void main(string args[]){
public void amethod(){
System.out.println(Hello);}
}
public class Test extends Base{}
What is the output of the program.
a) The code compiles and runs with out any outputb) Compilation failsc) Runtime error is thrownd) The code compiles and prints Hello
215 class Base{
public Integer method(Integer i){
return new Integer(100);}
public Long method(Long l){
return new Long(200);}
}
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public class Test{
public static void main(String args[]){Base b=new Base();
b.method(5);
}
}
For this questions I dont remember the options exactly.
Compilation Fails
216 Given some methods and asked to find vector methods
Remove method is used for deletion
Add method is used for adding the elements
http://java.sun.com/j2se/1.4.2/docs/api/java/util/Vector.html
217 Given some methods and asked to find Object class methods
The following are the methods in Object class:
clone(), equals(Object), finalize(), getClass(), hashCode(), to String(), wait(), notify(),
notifyAll(), wait(long), wait(long,int)
http://bioportal.weizmann.ac.il/course/prog2/java/api/java.lang.Object.html
218 Given one collection object and changed the reference of it in the next line and askedwhether it will through an error or not
219 Class A1{ }
Class A2{A1 [] a1= new A1[2]
A1 [] [] a2 = new A1 [2][2]
A1 [] [] [] a3=new A1 [2][2][2]SOP(a3[2][2][2]);
Array Index Out of Bounds Exception
220 Consider an array List having same objects and it is sent for sorting. After sorting the
arraylist will have the elements in the same order as that of before (True\False) -> False
221 As ArrayList size increases efficiency increases or decreases Increases efficiency
222 Class A{Public static void main(String args[]){
If (args.length
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Sop{True);
} else{Sop(false);
}
What is the output of the above if the program is run with the followingarguments?
A B C d
False
223 Session Bean can be private ( T\F) -> False
224 Given some statements regarding super constructer and asked to pick the correct one.
(Answer: Super will be present implicitly inside a constructer if there is no
argument constructor explicitly defined)
225 Method sort is present in collection class or collection interface ANS.
Collections class
http://java.sun.com/j2se/1.4.2/docs/api/java/util/Collections.html
226 Class A{
Public A(SringBuffer a){SOP{String Buffer);
}Public A(Sring a){
SOP{String );
}
public static void main (String args[]){A a1=new A(null);
}
}
What is the output of the above : . Ans: Compilation error
227 One question on overriding.. Super class method has one return type Sub
class overriding method has one return type.. asked to give the output.
Ans: Compilation Error
228 Differences between vector and ArrayList
Vector -> synchronized
Array List -> not Synchronized
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229 Which is synchronized.. hashmap\ hashtable ->Hash table
230 Which transaction attribute throws TransactionRequired Exception () Ans:
Mandatory
231 Created two objects using EJB create methods. Asked whether two are equal or
not..
232 output of.
String.toString().equals(String) and String.toString() = =String
new Object().equals(new Object()) -> True, True and False
233 How can you remove an element from a Vector?
1) delete method
2) cancel method
3) clear method
4) remove methodAnswer
4) remove method
234 byte[] b=new byte[1];int[] i=new int[1];long[] l=new long[1];
Object[] o=new Object[1];
System.out.println(b[0]+" "+i[0]+" "+l[0]+" "+o[0]);
Ans: 0 0 0 null
235 Tasks using a reference to EJBHome
(i) create & remove Session Bean
(ii)get a handle to Session Bean
(iii)create but not remove
236 FailFastIterator in Java
(i) No failFastIterator concept in Java(ii)FailFastIterator helps in iterating and conditioning.....
2 more options .. don remember
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fail-fastterm is about Java collections and theirs iteration and modification, which
are not synchronized.
http://www.javafaq.nu/java-article988.html
237 EJB timer service used with(i) CMP
(ii)CMP, BMP, MSD
(iii)MSD(iv)CMP,BMP
238 Correct about session beans
a)Session beans can be private
b)Session beans can be final
c)Sesson beans allow overloading
etc
239 array list contains values 1.6, 2 ,0.9, 0.2, 3, 1to get the output 1.6, 0.2, 0.9, 2, 3, 1Which of the following statements must be executed.
That means a part of the list must be sorted and should be printed. All the options
contain the same method but the argument values are changing. So see this method whichperforms the above sorting.
Sort(a,1,3)
240 What is the output of the program if the base class is not compiled .
Class Base{
//some code here
}public class Test extends Base{
public static void main(String args[]){
// some code here
}
}
I dont remember the code exactly. But it is like without compiling the base class test
class can get the functionality of the base class.
241 package com.base;
class Base{
Protected String name;// some more code
}
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package com.Test;
class Test extends Base{
public static void main(String args[]){
// some code here
}}
but in the above code the Base class is not imported in the Test class. The optionsare very close. Due to which reason it gives the compilation error.
Remember that compilation error also.
Compilation error
242 Requirements of Message Driven Bean
Correct Answers:
1) Must implement MessageDrivenBean and MessageListener interface
2) Class must be public
3) Class cannot be abstract or final
4) Must implement 1 onMessage method
5) Must implement one ejbCreate and one ejbRemove method
6) Must -> public constructor with no args
7) Must not define finalize method
The correct answer should be any of the above options
243 About this() and super()
Either this() or super() should be the first statement inside a constructor
If super() is the first line in a constructor, the second must be this()
The compiler always inserts super() as the first statement in a constructor.
244 Int a[][]={{1,2},{3,4,5},{6,8,9,0});
s.o.p(a[0][0]+ , +a[1][1]+,+a[2][2]);
Ans: 1, 4, 9
245 Class One{
Public One(){this(1)}Public One(String s){this(s+4,base);}
Public One(String a, String b){sop(a+b);}
}Public class Two{
Public Two(){sop(sub);}
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250 Given:Public static void before() {
Set set = new TreeSet ();
set.add("2");
set.add(3);set.add("1");
Iterator it = set.iterator ();
while (it.hasNext())System.out.print (it. next () + " ");
}
Which of the following statements are true?A. The before() method will print 1 2
B. The before() method will print 1 2 3
C. The before() method will print three numbers, but the order cannot be determined.
D. The before() method will not compile.
E. The before() method will throw an exception at runtime.
251 Is the fail fast iterator in java synchronized or unsyncronized?
Ans: Unsynchronized
252 EJB create remove begin methods will be present in
a)EJB Home
b)EJB OBJc)EJB Caller Principal
Ans : a
253 Given a[]=1.6,8.9,-9.6,2.0,0.9,3.5
The output required is 1.6,-9.6,8.9,2.0,0.9,3.5
A sort function like sort(a,0,4) sort(a,0,3) sort(a,1,3) like that Ans: sort(a,1,3)
254 A question on Core Java with options like
a)Every Object has a length method.
b)Every Object has a equals method.
c)Every Object has a sort() method
d)None of these
255 Which of the following is an application Exception
NOsuchObjectException ----system ExceptionEJBException ------------------system Exception
RemoteException------------ system Exception
None of these
APPLICATION EXCEPTIONS include the following
1.createException
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2.DuplicatekeyException
3.FinderException
4.ObjectNotFoundException
5.RemoveException
256 Map m=new TreeMap();
Sop(m instanceof collection)
Ans: False
257 What executes EJB components(EJB container wasnt an option)
1)Application server
2)EJB server
3)Web server
4)Database Server
258 which two elements must be included in the resource ref tag?
Ans: ,
259 When a transaction is rolled back on occurrence of a system exception which of thefollowing occurs?
a) The container removes the bean. -> The bean will be simply discarded.
b) An exception is thrown to the user
c) The exception is rethrown as an remote Exception
260 Correct form of deployment descriptor snippetAns :
. . .
cust
bankCustomer
. . .
261 Valid messaging models Ans: point to point, publish/subscribe