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DOEACC Society 2006 DOEACC B Level B2.52 - Introduction to Object Oriented Programming through Java ( ) - Question Paper

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C) ImageConsumer
D) ImageProducer
1.9 Which of the subsequent is not a wrapper class?
A) Vector
B) Character
C) Boolean
D) Integer
1.10 The class at the top of the AWT hierarchy is
A) Component
B) Window
C) Container
D) Frame
B2.52-R3 Page two of five July, 2006
2. every statement beneath is either actual or FALSE. select the most improper one
and ENTER in the “tear-off” sheet attached to the ques. paper, subsequent
instructions therein. (1 x 10)
2.1 If getParameter() returns NULL, then assigning the return value to a variable of kind
string may reason an exception to be thrown.
2.2 A string object once created cannot be replaced.
2.3 To ensure controlled access to a shared resource by multiple threads, use serialization.
2.4 All the methods in an abstract class must be declared as abstract.
2.5 In dynamic method dispatch, the call to overridden methods is resolved at runtime.
2.6 The objects System.out and System.in must be created explicitly by programmers.
2.7 It is possible to run garbage collector on demand by calling gc() method.
2.8 A static method cannot have local variables.
2.9 The CODE value in an tag must name a class file that is in the identical
directory as the calling HTML page.
2.10 The InetAddress class is used to encapsulate both the numerical IP address and the
domain name for that address.
3. Match words and phrases in column X with the nearest related meaning/
word(s)/phrase(s) in column Y. Enter your selection in the “tear-off” ans sheet
attached to the ques. paper, subsequent instructions therein. (1 x 10)
X Y
Clubbing data and methods together Packages
Java Interpreter Media Tracker
Short Circuit AND Container
Mechanism for organizing large programs Delegation Event Model
Root of character stream classes Text Area
A blank and semantic free window Inner class
Managing multiple images Data hiding
Event handling mechanism Bytecode
Class within a different class Canvas
Scrollable component to enter text JVM
Text field
Subclass
&&
Reader
Encapsulation
&
InputStream
B2.52-R3 Page three of five July, 2006
4. every statement beneath has a blank space to fit 1 of the word(s) or phrase(s) in
the list beneath. Enter your option in the “tear-off” ans sheet attached to the
ques. paper, subsequent instructions therein. (1 x 10)
A. JApplet B. s1.length C. flow
D. public E. Boolean F. float
G. ASCII H. throw I. init()
J. s1.length() K. finalize() L. Unicode
M. Float N. card O. update()
P. ServerSocket Q. border R. URL
S. run() T. private U. Throws
V. grid W. start() X. Applet
4.1 An object of ________ class can have POSITIVE_INFINTIY as a valid value.
4.2 Java uses ________ character set.
4.3 The length of a String object, s1, can be found using the expression ________.
4.4 The ________ method is called just before garbage collection.
4.5 To rethrow an exception use ________ keyword.
4.6 The implementation of an interface method must be declared as ________.
4.7 1st method called when an applet starts execution is ________.
4.8 ________ is the fundamental class of Java Swing.
4.9 The ________ class is used to specify the address of a resource on the Internet.
4.10 A(n) ________ layout manager arranges components in rows and columns form.
B2.52-R3 Page four of five July, 2006
PART TWO
(Answer any 4 questions)
5.
a) Write a Java program to learn in 2 matrices from the keyboard and calculate their sum.
Overload toString() method to display the outcome matrix in row and column form.
b) Differentiate ranging from the following:
i) static and instance members of a class
ii) method overloading and method overriding
(10+5)
6.
a) Write a Java program “FileCompare.java” to compare the contents of 2 files and
display the message “Same” if the contents of the 2 files are identical and “Different”
otherwise. The names of the files are to be passed to the program through the command
line arguments. Also write the command to invoke the program.
b) What do you understand by dynamic method dispatch? discuss with the help of an
example.
(9+6)
7. Design an applet to display 3 buttons “Red”, “Green” and “Blue”. The color of the
background modifications according to the button pressed by the user. Also, write the HTML
code to display the applet.
(15)
8.
a) Write a Java program to create a thread that displays odd numbers starting from one to
100.
b) Write a Java program to sort an array of strings entered through the keyboard.
(7+8)
9. Write short notes on any 3 of the following:
i) Exception Handling
ii) Packages
iii) Java Database Connectivity
iv) Interface versus classes
(5x3)
B2.52-R3 Page five of five July, 2006