[shabbir]

Question Number 1
Which code segment could execute the stored procedure "countRecs()" located in a database server?
Choice 1
Statement stmt = connection.createStatement();
stmt.execute("COUNTRECS()");
Choice 2
CallableStatement cs = con.prepareCall("{call COUNTRECS}");
cs.executeQuery();
Choice 3
StoreProcedureStatement spstmt = connection.createStoreProcedure("countRecs()");
spstmt.executeQuery();
Choice 4
PrepareStatement pstmt = connection.prepareStatement("countRecs()");
pstmt.execute();
Choice 5
Statement stmt = connection.createStatement();
stmt.executeStoredProcedure("countRecs()");
------------------------------------------------------------
Question Number 2
if(check4Biz(storeNum) != null) {}
Referring to the above, what datatype could be returned by method check4Biz()?
Choice 1
Boolean
Choice 2
int
Choice 3
String
Choice 4
char
Choice 5
byte
------------------------------------------------------------
Question Number 3
int j;
for(int i=0;i<14;i++) {
if(i<10) {
j = 2 + i;
}
System.out.println("j: " + j + " i: " + i);
}
What is WRONG with the above code?
Choice 1
Integer "j" is not initialized.
Choice 2
Nothing.
Choice 3
You cannot declare integer i inside the for-loop declaration.
Choice 4
The syntax of the "if" statement is incorrect.
Choice 5
You cannot print integer values without converting them to strings.
------------------------------------------------------------
Question Number 4
Which one of the following is a valid declaration of an applet?
Choice 1
Public class MyApplet extends java.applet.Applet {
Choice 2
Public Applet MyApplet {
Choice 3
Public class MyApplet extends applet implements Runnable {
Choice 4
Abstract class MyApplet extends java.applet.Applet {
Choice 5
Class MyApplet implements Applet {
------------------------------------------------------------
Question Number 5
int values[] = {1,2,3,4,5,6,7,8};
for(int i=0;i< X; ++i)
System.out.println(values[i]);
Referring to the above, what value for X will print all members of array "values"?
Choice 1
1
Choice 2
7
Choice 3
8
Choice 4
9
Choice 5
None, since there is a syntax error in the array declaration
------------------------------------------------------------
Question Number 6
public int m1(int x) {
int count=1;
try {
count += x;
count += m2(count);
count++;
}
catch(Exception e) { count -= x; }
return count;
}
Referring to the above, when m1(2) is invoked, m2() throws an ArithmeticException and m1() returns which one of the following?
Choice 1
1
Choice 2
2
Choice 3
3
Choice 4
4
Choice 5
The system will exit
------------------------------------------------------------
Question Number 7
System.getProperties().put(
"java.rmi.server.codebase",
"http://www.domain.com/classes/");
Which one of the following is a capability of the above code?
Choice 1
Override CLASSPATH
Choice 2
Register an rmi server on its host system
Choice 3
Set the location of all applets in a web server
Choice 4
Append CLASSPATH
Choice 5
Facilitate dynamic class loading for remote objects
------------------------------------------------------------
Question Number 8
Which one of the following statements is FALSE?
Choice 1
Java supports multi-threaded programming.
Choice 2
Threads in a single program can have different priorities.
Choice 3
Multiple threads can manipulate files and get user input at the same time.
Choice 4
Two threads can never act on the same object at the same time.
Choice 5
Threads are created and started with different methods.
------------------------------------------------------------
Question Number 9
1 public static void main(String[] s) {
2 String n1, n2, n3;
3 n1 = "n1";
4 n2 = "n2";
5 n3 = "n3";
6 {
7 String n4 = "inner";
8 n2 = n1;
9 }
10 n3 = null;
11 }
How many instances of the String will be eligible for garbage collection after line 10 in the above code snippet is executed?
Choice 1
0
Choice 2
1
Choice 3
2
Choice 4
3
Choice 5
The code will not compile.
------------------------------------------------------------
Question Number 10
Which code declares class A to belong to the mypackage.financial package?
Choice 1
package mypackage;
package financial;
Choice 2
import mypackage.*;
Choice 3
package mypackage.financial.A;
Choice 4
import mypackage.financial.*;
Choice 5
package mypackage.financial;

[prashantSum]

hi shabbir,

thanks for providing these questions,
I want more objectives on core java and advanced java, where can I get it...

[shabbir]

I have lots of them but dont have the time to compose them. Surely will do it for you and have it here soon. For the time being you can use http://www.ibiblio.org/javafaq/javafaq.html

[shabbir]

Question Number 1
How can you store a copy of an object at the same time other threads may be changing the object's properties?
Choice 1
Override writeObject() in ObjectOutputStream to make it synchronized.
Choice 2
Clone the object in a block synchronized on the object and serialize the clone.
Choice 3
Nothing special, since all ObjectOutputStream methods are synchronized.
Choice 4
Implement java.io.Externalizable instead of java.io.Serializable.
Choice 5
Give the thread performing storage a higher priority than other threads.
------------------------------------------------------------
Question Number 2
Which statement about static inner classes is true?
Choice 1
Static inner classes may access any of the enclosing classes members.
Choice 2
Static inner classes may have only static methods.
Choice 3
Static inner classes may not be instantiated outside of the enclosing class.
Choice 4
Static inner classes do not have a reference to the enclosing class.
Choice 5
Static inner classes are created when the enclosing class is loaded.
------------------------------------------------------------
Question Number 3
public void createTempFiles(String d) {
File f = new File(d);
f.mkdirs();
// more code here ...
}
What is the result if the createTempFiles statement below is executed on the code above on a Unix platform?
if (System.getSecurityManager() == null)
createTempFiles( "/tmp/myfiles/_3214" );
Choice 1
A java.lang.SecurityException is thrown.
Choice 2
The file "_3214" is created in the "/tmp/myfiles" directory.
Choice 3
The "myfiles" directory is created in the "/tmp" directory.
Choice 4
A java.io.DirectoryNotCreatedException is thrown.
Choice 5
The directory "/tmp/myfiles/_3214" is created if it doesn't already exist.
------------------------------------------------------------
Question Number 4
Which one of the following is NOT a valid difference between java.awt.Canvas and Panel?
Choice 1
Canvas's can display images directly.
Choice 2
Panel can hold other components (including Canvas).
Choice 3
You can draw bit-oriented items (lines and circles) onto a Canvas.
Choice 4
Layout managers work with Panel objects.
Choice 5
Panel cannot be redrawn by a call to repaint().
------------------------------------------------------------
Question Number 5
The javadoc utility produces which one of the following?
Choice 1
A listing of key features of all classes and methods in the source document
Choice 2
An html document for each class, interface, or package
Choice 3
A document for each program that outlines flow, structure, inputs, and outputs
Choice 4
A listing of all classes and packages used by a program
Choice 5
A list of all qualified comment tags in a source document with the source code removed
------------------------------------------------------------
Question Number 6
int values[] = {1,2,3,4,5,6,7,8};
for(int i=0;i< X;)
System.out.println(values[i++]);
Referring to the above, what value for X will print all members of array "values"?
Choice 1
7
Choice 2
8
Choice 3
9
Choice 4
None, because the first value is never printed
Choice 5
None, since there is a syntax error in the array declaration
------------------------------------------------------------
Question Number 7
What causes an IllegalMonitorStateException?
Choice 1
A thread calls wait() or notify() before acquiring an object's monitor.
Choice 2
Two threads call a static synchronized method at the same time.
Choice 3
A thread invokes wait() on an object that is already waiting.
Choice 4
A thread invokes notify() on an object that is not waiting.
Choice 5
Two threads modify the same variable in the same object at the same moment.
------------------------------------------------------------
Question Number 8
double x=0;
x= (check().equals("1")) ? getSales() : nextStore();
What datatype could be returned by method check() as shown above?
Choice 1
int
Choice 2
boolean
Choice 3
Object
Choice 4
byte
Choice 5
char
------------------------------------------------------------
Question Number 9
1: class Class1 {
2: public static void main(String args[]) {
3: int total = 0;
4: int[] i = new int[3];
5: for(int j=1;j<= i.length; j++)
6: total += (i[j] = j);
7: System.out.println(total);
8: }
9: }
What is the output of the program above?
Choice 1
3
Choice 2
4
Choice 3
6
Choice 4
None. The system will throw an ArrayIndexOutOfBoundsException.
Choice 5
None. The compiler will throw a syntax error on line 6.
------------------------------------------------------------
Question Number 10
System.getProperties().put(
"java.rmi.server.codebase",
"http://www.domain.com/classes/");
Which one of the following is a capability of the above code?
Choice 1
Set the location of all applets in a web server
Choice 2
Append CLASSPATH
Choice 3
Register an rmi server on its host system
Choice 4
Facilitate dynamic class loading for remote objects
Choice 5
Override CLASSPATH
------------------------------------------------------------
Question Number 11
char ch1,ch2;
try { ch1 = (char) System.in.read(); }
catch(Exception e) {}
switch(ch1) {
case 'a':
ch2 = '1';
case 'b':
ch2 = '2';
case 'c':
ch2 = '3';
default:
ch2 = '4';
}
Referring to the above, during execution the user presses "b", what is the ending value of "ch2"?
Choice 1
'1'
Choice 2
'2'
Choice 3
'3'
Choice 4
'4'
Choice 5
null
------------------------------------------------------------
Question Number 12
Which java.sql class can return multiple result sets?
Choice 1
Statement
Choice 2
PreparedStatement
Choice 3
Any class derived from Statement that implements MultiResultSet
Choice 4
CallableStatement
Choice 5
ResultSet with the "multiple" property set to "true"
------------------------------------------------------------
Question Number 13
class A {
B b = new B();
C c = (C) b;
}
Referring to the above, when is the cast of "b" to class C allowed?
Choice 1
B and C are subclasses of the same superclass.
Choice 2
If B and C are superclasses of the same subclass.
Choice 3
C is a final class.
Choice 4
B is a subclass of C.
Choice 5
B is a superclass of C.
------------------------------------------------------------
Question Number 14
How can you have a "try" block that invokes methods that throw two different exceptions?
Choice 1
Catch one exception in a "catch" block and the other in a "finally" block.
Choice 2
Setup nested "catch" blocks for each exception.
Choice 3
Catch one exception in a "catch" block and the other via the return value.
Choice 4
Use wait() between the calls to process all exceptions before continuing.
Choice 5
Include a "catch" block for each exception.
------------------------------------------------------------
Question Number 15
static {
System.loadLibrary("mNativeLib");
}

public int myMethod(int count) {

Additional code here

}
Referring to the above, if myMethod() is implemented in native code library "mNativeLib", how must its declaration be changed?
Choice 1
Replace it with public System.nativeMethod("myMethod(int)");.
Choice 2
Replace myMethod()'s code with System.execute("mNativeLib", myMethod(count));.
Choice 3
Move it into the static code block.
Choice 4
Replace it with public native int myMethod(int count);.
Choice 5
Replace it with native myMethod(int count) {}.
------------------------------------------------------------
Question Number 16
Which one of the following is the equivalent of main() in a thread?
Choice 1
start()
Choice 2
go()
Choice 3
run()
Choice 4
begin()
Choice 5
The class constructor
------------------------------------------------------------
Question Number 17
What happens if a class defines a method with the same name and parameters as a method in its superclass?
Choice 1
The compiler automatically renames the subclass method.
Choice 2
The program runs since because overriding methods is allowed
Choice 3
The program throws a DuplicateMethod exception.
Choice 4
The subclass methods will be ignored.
Choice 5
The compiler shows a DuplicateMethod error.
------------------------------------------------------------
Question Number 18
class A {
static int getIt(int i) {
return i;
}
}
What is a consequence of "static" in the code above?
Choice 1
getIt() returns a static int
Choice 2
getIt() can only access static properties of class A
Choice 3
getIt() can be overridden
Choice 4
getIt() is invoked only by other static methods
Choice 5
Subclasses of class A must override method getIt()
------------------------------------------------------------
Question Number 19
1 public static void main(String[] s) {
2 String n1, n2, n3;
3 n1 = "n1";
4 n2 = "n2";
5 n3 = "n3";
6 {
7 String n4 = "inner";
8 n2 = n1;
9 }
10 n3 = null;
11 }
How many instances of the String will be eligible for garbage collection after line 10 in the above code snippet is executed?
Choice 1
0
Choice 2
1
Choice 3
2
Choice 4
3
Choice 5
The code will not compile.
------------------------------------------------------------
Question Number 20
try {
int values[] = {1,2,3,4,3,2,1};
for (int i = values.length-1; i >= 0; i++)
System.out.print( values[i] + " " );
} catch (Exception e) {
System.out.print("2" + " ");
} finally {
System.out.print("3" + " ");
}
What is the output of the program above?
Choice 1
1 2
Choice 2
1 3
Choice 3
1 2 3 4 3 2 1
Choice 4
1 2 3
Choice 5
1 2 3 4 3 2 1 3
------------------------------------------------------------
Question Number 21
native int computeAll();
Referring to the above, the keyword "native" indicates which one of the following?
Choice 1
That computeAll() is undefined and must be overridden
Choice 2
That computeAll() is an external method implemented in another language
Choice 3
That computeAll() is defined in the superclass
Choice 4
That the compiler must use file computeAll.java for platform-specific code
Choice 5
That computeAll() is an operating system command
------------------------------------------------------------
Question Number 22
int i=0;
double value = 1.2;
String str = new String("1.2");
Boolean flag = true;
Which is a valid use of variable "value" as shown above?
Choice 1
value = str;
Choice 2
if(value.equals( str )) System.out.println(str);
Choice 3
if(value) i++;
Choice 4
value += flag;
Choice 5
value = ++i;
------------------------------------------------------------
Question Number 23
class A implements Cloneable {
public int i, j, k;
String str = ("Hello There");

public Object clone() {
try {
return super.clone();
} catch (CloneNotSupportedException e) {}
}
}

class B extends A {
public B() {
i = 5;
j = 3;
k= -4;
}
}
Referring to the above, what will happen when the following code is executed?

B a = new B();
B b = (B) a.clone();
Choice 1
A CloneNotSupportedException is thrown.
Choice 2
Two identical class B objects are created.
Choice 3
One instance of class B is created with two pointers: "a" and "b".
Choice 4
Identical threads "a" and "b" are created.
Choice 5
Object "a" is instantiated and "b" is created as an inner class of "B".
------------------------------------------------------------
Question Number 24
What class represents the U.S. Mountain time zone in date/time calculations?
Choice 1
java.util.Locale
Choice 2
java.util.GregorianCalendar
Choice 3
java.util.Date
Choice 4
java.util.Calendar
Choice 5
java.util.SimpleTimeZone
------------------------------------------------------------
Question Number 25
public double SquareRoot( double value ) throws ArithmeticException
{
if (value >= 0) return Math.sqrt( value );
else throw new ArithmeticException();
}

public double func(int x) {
double y = (double) x;
try {
y = SquareRoot( y );
}
catch(ArithmeticException e) { y = 0; }
finally { --y; }
return y;
}
Referring to the above, what value is returned when method func(4) is invoked?
Choice 1
-2
Choice 2
-1
Choice 3
0
Choice 4
1
Choice 5
2
------------------------------------------------------------
Question Number 26
short tri[][] = new short[10][];
for(int i = 0,count =0 ; i < tri.length; i++ ) {
tri[i]= new short[i+1];
for(int j = 0 ; j < tri[i].length; j++ ) {
tri[i][j]= (short) count++;
}
}
At what array index does the array "tri" have the value 18 as shown above?
Choice 1
tri[3][3]
Choice 2
tri[4][4]
Choice 3
tri[5][3]
Choice 4
tri[6][2]
Choice 5
tri[4][5]
------------------------------------------------------------
Question Number 27
Which one of the following is NOT addressed by the java.security package?
Choice 1
Message digests
Choice 2
Access control lists
Choice 3
Cookies
Choice 4
Key management
Choice 5
Digital signatures
------------------------------------------------------------
Question Number 28
What concern is legitimate when overriding the java.lang.Object.finalize method?
Choice 1
The method must be thread safe.
Choice 2
The method may never execute.
Choice 3
The method must handle all exceptions.
Choice 4
The method must handle multiple concurrent invocations.
Choice 5
The method must ensure all object references are set to null.
------------------------------------------------------------
Question Number 29
Which one of the following is a limitation of subclassing the Thread class?
Choice 1
You must catch the ThreadDeath exception.
Choice 2
You must implement the Threadable interface.
Choice 3
You cannot have any static methods in the class.
Choice 4
You must declare the class final.
Choice 5
You cannot subclass any other class.
------------------------------------------------------------
Question Number 30
char ch1=' ';
int j = 0;

for(int i = 0 ; i < 5; i++) {
try { ch1 = (char) System.in.read(); }
catch(Exception e) {}

if (ch1 == 'a') break;
else if (ch1 == 'b') continue;
else if (ch1 == 'c') i--;
else if (ch1 == 'd') j++;

j++;
}
System.out.println( j );
What is the output during execution if the user types in "bdcda" as shown above?
Choice 1
2
Choice 2
3
Choice 3
4
Choice 4
5
Choice 5
6
------------------------------------------------------------
Question Number 31
1: import java.io.*;
2: class PrintThread extends Thread {
3: private static Object o = new Object();
4: private static DataOutputStream out = //... set to some output file
5: private int I;
6:
7: public PrintThread(int I) {
8: this.I = I;
9: }
10: public void run() {
11: while(true) {
12: try {
13: out.writeBytes("Hello all from thread " + I +"\r\n");
14: } catch (Exception e) {}
15: }
16: }
17: public static void main(String[] s) {
18: for (int i = 0; i < 5; i++ ) {
19: (new PrintThread(i)).start();
20: }
21: }
22: }
How could you ensure that each line of output from the above program came from an individual thread?
Choice 1
Make the run method "synchronized".
Choice 2
Insert the following code between line 11 and 12:
try {
sleep(100);
} catch(Exception e) {}
Choice 3
Add the "synchronized" modifier to the DataOuputStream "out" variable declaration.
Choice 4
Insert the following line between line 12 and 13:
synchronized(o) {

and this line between line 13 and 14
}
Choice 5
Insert the following code between line 11 and 12:
yield();
------------------------------------------------------------
Question Number 32
Which one of the following is a reason to double-buffer animations?
Choice 1
To draw each image to the screen twice to eliminate white spots
Choice 2
To use a small image as wallpaper and a transparent image as the actual frame
Choice 3
To put multiple frame in the same file and uses cropImage() to select the desired frame
Choice 4
To draw the next frame to an off-screen image object before displaying to eliminate flicker
Choice 5
To prevent "hanging" using a MediaTracker object to ensure all frames are loaded before beginning
------------------------------------------------------------
Question Number 33
String s1 = new String("AbraCadabra");
String s2 = new String(" willow woo");

String s3;
s3=s1.substring(1,5) + s2.toUpperCase().trim().substring(1,5);
Referring to the above, what is in s3 after execution?
Choice 1
braCaWILLO
Choice 2
braCILLO
Choice 3
braCWILL
Choice 4
braCaILLOW
Choice 5
AbraC WILL
------------------------------------------------------------
Question Number 34
class Class1 {
static int i=0;
public static void main(String args[]) {
for(int j=1;j<args.length;j+=2) {
i += Integer.parseInt(args[j]);
}
System.out.println(i);
}
}
What parameters could be passed on the command-line so that the output of the program above is "6"?
Choice 1
1 2 3 4
Choice 2
6 5 1
Choice 3
6
Choice 4
None. The system will throw an ArrayIndexOutOfBounds Exception.
Choice 5
None. The compiler will issue an error message because an exception must be caught when invoking parseInt().
------------------------------------------------------------
Question Number 35
What is the purpose of the java.text package?
Choice 1
To perform font management between different platforms
Choice 2
To provide classes for manipulating Strings
Choice 3
To allow formatting of text data for specific geographic locations
Choice 4
To facilitate spelling and grammar checks
Choice 5
To render text strings on java.awt.Container objects
------------------------------------------------------------
Question Number 36
Which class formats the exact time for a web page used by people in India?
Choice 1
java.util.GregorianCalendar
Choice 2
java.util.Time
Choice 3
java.text.TimeFormat
Choice 4
java.util.Date
Choice 5
java.text.SimpleDateFormat
------------------------------------------------------------
Question Number 37
Compared to connection-oriented sockets, which statement about connectionless sockets is true?
Choice 1
They support only character streams.
Choice 2
They do not support two-way communication.
Choice 3
They do not guarantee delivery or order of receipt.
Choice 4
They can transmit to multiple receivers at the same time.
Choice 5
They are less efficient and slower.
------------------------------------------------------------
Question Number 38
class MyButton extends Button {
private int pressCount=0;
private static Panel panel;

public MyButton(String txt) {
super( txt );
if (panel != null) panel=new Panel();
}
protected void finalize() throws Throwable {
panel.add( this );
System.out.println("GoodBye!");
}
}
What is WRONG with the code above?
Choice 1
Super class Button doesn't have a public constructor which takes a String as a parameter.
Choice 2
The finalize method must be declared public.
Choice 3
Accessing a static method inside the constructor call.
Choice 4
The paint() method is not overridden.
Choice 5
class MyButton cannot ever get garbage collected correctly.
------------------------------------------------------------
Question Number 39
_______________
| Choice A \/ |
The widget shown above is similar to which standard java.awt class?
Choice 1
Menu
Choice 2
PullMenu
Choice 3
List
Choice 4
Choice
Choice 5
Select
------------------------------------------------------------
Question Number 40
What class is subclassed to package several locale-specific versions of a set of greetings used by an application?
Choice 1
java.text.RuleBasedCollator
Choice 2
java.text.CollationKey
Choice 3
java.util.ResourceBundle
Choice 4
java.util.TimeZone
Choice 5
java.util.Locale
------------------------------------------------------------

[shabbir]

Question Number 1
import java.lang.reflect.Field;
MyClass myClass = new MyClass();
try {
Class cl=Class.forName("MyClass");
Field res=cl.getDeclaredField("count");
res.set(myClass,"5");
} catch(Exception e) {}
What is accomplished by the above code?
Choice 1
The first 5 member variables of myClass are copied to "res".
Choice 2
The value of myClass.count is set to 5.
Choice 3
Object "res" is created with its "count" member set to 5.
Choice 4
5 copies of the myClass object are created.
Choice 5
The number of MyClass fields described in "cl" is set to 5.
---------------------------------------------------------------------
Question Number 2
XXX = new Integer("155").toString();
What datatype or class is XXX in the above code segment?
Choice 1
byte
Choice 2
char[]
Choice 3
StringBuffer
Choice 4
String
Choice 5
long
---------------------------------------------------------------------
Question Number 3
What class can access file attributes, create new files and create directories?
Choice 1
java.io.FileSystem
Choice 2
java.io.RandomAccessFile
Choice 3
java.util.Writer
Choice 4
System or Runtime
Choice 5
java.io.File
---------------------------------------------------------------------
Question Number 4
class A {
int i, j, k;
public A(int ii) { i = ii; }
public A() {
k = 1;
}
}
Referring to the above, what code instantiates an object of class A?
Choice 1
new A(this);
Choice 2
A a = new A(3);
Choice 3
A(3) a;
Choice 4
A a = new A(4,8);
Choice 5
A a = new A(3.3);
---------------------------------------------------------------------
Question Number 5
void printOut( int I ) {
if (I==0) return;
for(int i=I;i>0;i--) {
System.out.println("Line " + i);
}
printOut(I-1);
}
What value should be passed to the method printOut, shown above, so that ten lines will be printed?
Choice 1
2
Choice 2
3
Choice 3
4
Choice 4
5
Choice 5
6
---------------------------------------------------------------------
Question Number 6
class A {
public static void main(String args[]) {
char initial = "c";
switch (initial) {
case "j":
System.out.print("John ");
break;
case "c":
System.out.print("Chuck ");
case "t":
System.out.print("Ty ");
break;
case "s":
System.out.print("Scott ");
default:
System.out.print("All");
}
}
}
What is the output from the code above?
Choice 1
John Chuck Ty Scott All
Choice 2
A compilation error will occur.
Choice 3
Chuck Ty
Choice 4
Ty
Choice 5
Chuck
---------------------------------------------------------------------
Question Number 7
How can you insure compatibility of persistent object formats between different versions of Java?
Choice 1
Override the default ObjectInputStream and ObjectOutputStream.
Choice 2
Implement your own writeObject() and readObject() methods.
Choice 3
Add "transient" variables.
Choice 4
Implement java.io.Serializable.
Choice 5
Make the whole class transient
---------------------------------------------------------------------
Question Number 8
What does it mean if a method is final synchronized?
Choice 1
Methods which are synchronized cannot be final.
Choice 2
This is the same as declaring the method private.
Choice 3
Only one synchronized method can be invoked at a time for the entire class.
Choice 4
The method cannot be overridden and is always threadsafe.
Choice 5
All final variables referenced in the method can be modified by only one thread at a time.
---------------------------------------------------------------------
Question Number 9
class HelloWorld extends java.awt.Canvas {
String str = "Hello World";

public void paint(java.awt.Graphics g) {
java.awt.FontMetrics fm = g.getFontMetrics();
g.setColor(java.awt.Color.black);
java.awt.Dimension d = getSize();
__?__
}
}
Which one of the following code segments can be inserted into the method above to paint "Hello World" centered within the canvas?
Choice 1
g.drawText( str, 0, 0);
Choice 2
g.drawString( str, d.width/2, d.height/2 );
Choice 3
g.drawString( str, d.width/2 - fm.stringWidth(str)/2, d.height/2 -
fm.getHeight()/2);
Choice 4
g.translate( d.width/2 - fm.stringWidth(str), d.height/2 - fm.getHeight());
g.drawString( str, 0, 0);
Choice 5
g.drawText( str, d.width, d.height, Font.CENTERED );
---------------------------------------------------------------------
Question Number 10
String url=new String("http://www.tek.com");
How can you retrieve the content of the above URL?
Choice 1
Socket content = new Socket(new URL(url)).collect();
Choice 2
String content = new URLConnection(url).collect();
Choice 3
Object content = new URL(url).getContent();
Choice 4
Object content = new URLConnection(url).getContent();
Choice 5
String content = new URLHttp(url).getString();
---------------------------------------------------------------------
Question Number 11
What is NOT a typical feature of visual JavaBeans?
Choice 1
Persistence, so a bean can be customized in an application builder, saved, and reloaded later.
Choice 2
Properties, both for customization and for programmatic use.
Choice 3
Customization, so that when using an application builder a developer can customize the appearance and behavior of a bean.
Choice 4
Distributed framework, so the visual component resides on the client, while the logic resides on the server.
Choice 5
Events, so that a simple communication metaphor can be used to connect beans.
---------------------------------------------------------------------
Question Number 12
Which one of the following describes the difference between StringBuffer and String?
Choice 1
StringBuffer is used only to buffer data from an input or output stream.
Choice 2
StringBuffer allows text to be changed after instantiation.
Choice 3
StringBuffer holds zero length Strings.
Choice 4
StringBuffer supports Unicode.
Choice 5
StringBuffer is an array of Strings.
---------------------------------------------------------------------
Question Number 13
public double SquareRoot( double value ) throws ArithmeticException
{
if (value >= 0) return Math.sqrt( value );
else throw new ArithmeticException();
}

public double func(int x) {
double y = (double) x;
y *= -9.0;
try {
y = SquareRoot( y );
}
catch(ArithmeticException e) { y /= 3; }
finally { y += 10; }
return y;
}
Referring to the above, what value is returned when method func(9) is invoked?
Choice 1
-37
Choice 2
-27
Choice 3
-17
Choice 4
9
Choice 5
NaN
---------------------------------------------------------------------
Question Number 14
1: Date myDate = new Date();
2: DateFormat dateFormat = DateFormat.getDateInstance();
3: String myString = dateFormat.format(myDate);
4: System.out.println( "Today is " + myString );
How can you change line 2 above so that the date is displayed in the same format used in China?
Choice 1
java.util.Local locale = java.util.Locale.getLocale( java.util.Locale.CHINA );
DateFormat dateFormat = DateFormat.getDateInstance( locale );
Choice 2
java.util.Local locale = java.util.Locale.getLocale("China");
DateFormat dateFormat = DateFormat.getDateInstance( locale );
Choice 3
DateFormat dateFormat = DateFormat.getDateInstance();
dateFormat.setLocale( java.util.Locale.CHINA );
Choice 4
DateFormat dateFormat = DateFormat.getDateInstance(
DateFormat.SHORT, java.util.Locale.CHINA);
Choice 5
DateFormat.setLocale( java.util.Locale.CHINA );
DateFormat dateFormat = DateFormat.getDateInstance();
---------------------------------------------------------------------
Question Number 15
Which one of the following operators has a higher precedence than the modulus operator, % ?
Choice 1
-
Choice 2
*
Choice 3
+
Choice 4
/
Choice 5
. (dot)
---------------------------------------------------------------------
Question Number 16
double dd;
java.util.Random r = new Random(33);
dd = r.nextGaussian();
Referring to the above, after execution, double dd contains a value that is distributed approximately ________ with a standard deviation of ________ and mean of ________.
Choice 1
uniformly, 0, 33
Choice 2
normally, 1, 0
Choice 3
uniformly, 1, 33
Choice 4
normally, 1, 33
Choice 5
normally, 3, 3
---------------------------------------------------------------------
Question Number 17
How can you give other classes direct access to constant class attributes but avoid thread-unsafe situations?
Choice 1
Declare the attributes as public static final.
Choice 2
Implement the "java.lang.SingleThreaded" interface.
Choice 3
Declare the attributes to be synchronized.
Choice 4
This is not possible.
Choice 5
Declare the attributes as protected.
---------------------------------------------------------------------
Question Number 18
import java.io.*;
import java.net.*;
public class NetClient {
public static void main(String args[]) {
try {
Socket skt = new Socket("host",88);
In the above code, what type of connection is Socket object "skt"?
Choice 1
UDP
Choice 2
Connectionless
Choice 3
FTP
Choice 4
HTTP
Choice 5
Connection-oriented
---------------------------------------------------------------------
Question Number 19
float ff;
int gg = 99;
Referring to the above, what is the correct way to cast an integer to a float?
Choice 1
ff = (float) gg
Choice 2
ff (float) = gg
Choice 3
ff = (float: gg
Choice 4
ff = (float) %% gg
Choice 5
You cannot cast an integer to a float
---------------------------------------------------------------------
Question Number 20
Which one of the following is a reason to double-buffer animations?
Choice 1
To draw each image to the screen twice to eliminate white spots
Choice 2
To prevent "hanging" using a MediaTracker object to ensure all frames are loaded before beginning
Choice 3
To draw the next frame to an off-screen image object before displaying to eliminate flicker
Choice 4
To put multiple frame in the same file and uses cropImage() to select the desired frame
Choice 5
To use a small image as wallpaper and a transparent image as the actual frame
---------------------------------------------------------------------
Question Number 21
Which one of the following is NOT a valid java.lang.String declaration?
Choice 1
String myString = new String("Hello");
Choice 2
char data[] = {'a','b','c'};
String str = new String(data);
Choice 3
String myString = new String(5);
Choice 4
String cde = "cde";
Choice 5
String myString = new String();
---------------------------------------------------------------------
Question Number 22
int count = 0;
while(count++ < X ) {
System.out.println("Line " + count);
}
What value for X above will print EXACTLY 10 lines to standard output?
Choice 1
0
Choice 2
5
Choice 3
9
Choice 4
10
Choice 5
11
---------------------------------------------------------------------
Question Number 23
package mypackage.compute.financial;
Referring to the above, where must Class files belonging to the package be stored?
Choice 1
In any classpath directory
Choice 2
In directory mypackage under the current working directory
Choice 3
In mypackage/compute/financial under any directory in the classpath
Choice 4
In mypackage/compute/classpath under any directory
Choice 5
In any directory defined in the path of the java interpreter
---------------------------------------------------------------------
Question Number 24
A monitor called "m" has two threads waiting with the same priority. One of the threads is "thread3". How can you inform "thread3" so that it alone moves from the Waiting state to the Ready state?
Choice 1
thread3.notify();
Choice 2
m.notify(thread3);
Choice 3
thread3.start();
Choice 4
notify(thread3);
Choice 5
thread3.run()
---------------------------------------------------------------------
Question Number 25
if(check4Biz(storeNum) < 10) {}
Referring to the above, what datatype could be returned by method check4Biz()?
Choice 1
char[]
Choice 2
Boolean
Choice 3
int
Choice 4
String
Choice 5
java.util.Bitset
---------------------------------------------------------------------
Question Number 26
Which one of the following is a limitation of subclassing the Thread class?
Choice 1
You must implement the Threadable interface.
Choice 2
You cannot have any static methods in the class.
Choice 3
You must declare the class final.
Choice 4
You must catch the ThreadDeath exception.
Choice 5
You cannot subclass any other class.
---------------------------------------------------------------------
Question Number 27
String os = System.getProperty("os.name");
When the above code is executed in an untrusted applet, which code segment will the JVM execute internally?
Choice 1
throw new java.lang.SecurityException();
Choice 2
System.checkStackTrace();
Choice 3
return SecurityManager.getProperty("os.name");
Choice 4
SecurityManager().getAccess("Property", "os.name");
Choice 5
System.getSecurityManager().checkPropertyAccess("o s.name");
---------------------------------------------------------------------
Question Number 28
public void createTempFiles(String d) {
File f = new File(d);
f.mkdirs();
// more code here ...
}
What is the result if the createTempFiles statement below is executed on the code above on a Unix platform?
if (System.getSecurityManager() == null)
createTempFiles( "/tmp/myfiles/_3214" );
Choice 1
The file "_3214" is created in the "/tmp/myfiles" directory.
Choice 2
A java.lang.SecurityException is thrown.
Choice 3
The "myfiles" directory is created in the "/tmp" directory.
Choice 4
A java.io.DirectoryNotCreatedException is thrown.
Choice 5
The directory "/tmp/myfiles/_3214" is created if it doesn't already exist.
---------------------------------------------------------------------
Question Number 29
static void printIt( int count ) {
if ((count % 2) == 0)
System.err.println("StdErr: Line " + count + "\n");
else {
System.out.println("StdOut: Line " + count + "\n");
}
if (count == 0) return;
else printIt(count-1);
}

public static void main(String [] args) {
printIt( X );
}
What value for X above will print EXACTLY ten lines to standard output, in the fewest number of recursive calls?
Choice 1
5
Choice 2
9
Choice 3
10
Choice 4
19
Choice 5
20
---------------------------------------------------------------------
Question Number 30
for(int i=0;i<5;i= X ) {
System.out.println("Line " + i);
i++;
}
Referring to the above, what value for X will cause a never-ending loop?
Choice 1
A compiler error occurs
Choice 2
4
Choice 3
5
Choice 4
6
Choice 5
10
---------------------------------------------------------------------
Question Number 31
System.err represents an instance of what class?
Choice 1
java.lang.System
Choice 2
java.io.PrintWriter
Choice 3
java.io.OutputStreamWriter
Choice 4
java.io.PrintStream
Choice 5
java.io.BufferedOutputStream
---------------------------------------------------------------------
Question Number 32
<import java.io.*;

Additional code here

FileInputStream f = new FileInputStream("store");
ObjectInputStream in = new ObjectInputStream(f);
Object obj = in.readObject();
Referring to the above, what additional code will produce the type of object represented by "obj"?
Choice 1
Classloader.getInstance(obj);
Choice 2
obj.getClass().getName();
Choice 3
String name;
String all[] = {"String","StringBuffer","Array", others here};
for(int i=0;i<all.length;i++)
if(name = all[i].equals(Class.instanceOf(all[i]))) break;
Choice 4
obj.toString();
Choice 5
new Class.getName(obj);
---------------------------------------------------------------------
Question Number 33
What code declares a two dimensional array of integers called "intArray"?
Choice 1
int intArray[] = {int intArray[]};
Choice 2
int intArray[][];
Choice 3
two dimensional arrays are not allowed in java
Choice 4
int intArray{int intArray[]};
Choice 5
int **intArray;
---------------------------------------------------------------------
Question Number 34
class PrimeThread extends Thread {
long minPrime;
long result;

PrimeThread(long minPrime) {
this.minPrime = minPrime;
}
public void run() {
// compute primes larger than minPrime
// . . .
}
}
Referring to the above, which code segment could create and start PrimeThread?
Choice 1
Thread p = new Thread(new PrimeThread(143));
p.run();
Choice 2
PrimeThread p = new PrimeThread();
p.run();
Choice 3
PrimeThread(143).run();
Choice 4
Runnable r = new Runnable( PrimeThread(143) );
r.start();
Choice 5
(new PrimeThread(143)).start();
---------------------------------------------------------------------
Question Number 35
class MyCanvas extends java.awt.Canvas {
int count = 0;
public MyCanvas() {}
public void paint(Graphics g) {
super.paint(g);
}
public int paint(Graphics g) {
super.paint(g);
return ++count;
}
}
Referring to the above, what is WRONG with class MyCanvas?
Choice 1
All methods must declare return datatypes.
Choice 2
There are multiple methods named paint().
Choice 3
A method cannot have the same name as its class.
Choice 4
Overloaded methods cannot have the same input types with a different return type.
Choice 5
java.awt.Canvas is an interface, so it must be implemented, not extended.
---------------------------------------------------------------------
Question Number 36
Objects can be cast to another class when which one of the following is the case?
Choice 1
Both classes are direct subclasses of the same superclass.
Choice 2
The source class is not abstract or static.
Choice 3
The target class is a subclass of the source class.
Choice 4
Both classes are subclasses of the same abstract superclass.
Choice 5
The target class is a final class.
---------------------------------------------------------------------
Question Number 37
What happens if you load a JDBC driver that is NOT fully compliant with JDBC?
Choice 1
The driver will fail bytecode verification.
Choice 2
The driver would function for applications, but not applets.
Choice 3
The driver may work for some actions and not for others.
Choice 4
The SecurityManager will throw a SecurityException when a connection is attempted.
Choice 5
The DriverManager object will refuse to register it.
---------------------------------------------------------------------
Question Number 38
To sign a .class file, the javakey tool does which one of the following?
Choice 1
Embeds a signature flag in the class file attributes
Choice 2
Places a signature byte[] array at the bottom of the class file
Choice 3
Creates an inner class containing the signature data
Choice 4
Places a signature byte[] array at the top of the class file
Choice 5
Places special signature files in a JAR bundle
---------------------------------------------------------------------
Question Number 39
float f = 5.0f;
float g = 2.0f;
double h;

h = 3+f%g+2;
Referring to the above, what is the expected value for h after execution?
Choice 1
5.2
Choice 2
6
Choice 3
7
Choice 4
7.5
Choice 5
9
---------------------------------------------------------------------
Question Number 40
Connection con = DriverManager.getConnection (
"jdbc:odbc:wombat", "login", "password");
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery("SELECT a, b, c FROM Table1");
while (rs.next()) {
Integer x = rs.getInt("c");
String s = rs.getString("a");
Float f = rs.getFloat("b");
}
What is WRONG with the code above?
Choice 1
Retrieval of the fields is in the wrong order.
Choice 2
The password must be encrypted before being sent to the DriverManager.
Choice 3
The Driver's URL is in the wrong format.
Choice 4
The ResultSet class returns primitive types for integers and floats.
Choice 5
The SQL statement is invalid.
---------------------------------------------------------------------

[shabbir]

Question Number 1
Which code segment could execute the stored procedure "countRecs()" located in a database server?
Choice 1
Statement stmt = connection.createStatement();
stmt.execute("COUNTRECS()");
Choice 2
CallableStatement cs = con.prepareCall("{call COUNTRECS}");
cs.executeQuery();
Choice 3
StoreProcedureStatement spstmt = connection.createStoreProcedure("countRecs()");
spstmt.executeQuery();
Choice 4
PrepareStatement pstmt = connection.prepareStatement("countRecs()");
pstmt.execute();
Choice 5
Statement stmt = connection.createStatement();
stmt.executeStoredProcedure("countRecs()");
------------------------------------------------------------
Question Number 2
if(check4Biz(storeNum) != null) {}
Referring to the above, what datatype could be returned by method check4Biz()?
Choice 1
Boolean
Choice 2
int
Choice 3
String
Choice 4
char
Choice 5
byte
------------------------------------------------------------
Question Number 3
int j;
for(int i=0;i<14;i++) {
if(i<10) {
j = 2 + i;
}
System.out.println("j: " + j + " i: " + i);
}
What is WRONG with the above code?
Choice 1
Integer "j" is not initialized.
Choice 2
Nothing.
Choice 3
You cannot declare integer i inside the for-loop declaration.
Choice 4
The syntax of the "if" statement is incorrect.
Choice 5
You cannot print integer values without converting them to strings.
------------------------------------------------------------
Question Number 4
Which one of the following is a valid declaration of an applet?
Choice 1
Public class MyApplet extends java.applet.Applet {
Choice 2
Public Applet MyApplet {
Choice 3
Public class MyApplet extends applet implements Runnable {
Choice 4
Abstract class MyApplet extends java.applet.Applet {
Choice 5
Class MyApplet implements Applet {
------------------------------------------------------------
Question Number 5
int values[] = {1,2,3,4,5,6,7,8};
for(int i=0;i< X; ++i)
System.out.println(values[i]);
Referring to the above, what value for X will print all members of array "values"?
Choice 1
1
Choice 2
7
Choice 3
8
Choice 4
9
Choice 5
None, since there is a syntax error in the array declaration
------------------------------------------------------------
Question Number 6
public int m1(int x) {
int count=1;
try {
count += x;
count += m2(count);
count++;
}
catch(Exception e) { count -= x; }
return count;
}
Referring to the above, when m1(2) is invoked, m2() throws an ArithmeticException and m1() returns which one of the following?
Choice 1
1
Choice 2
2
Choice 3
3
Choice 4
4
Choice 5
The system will exit
------------------------------------------------------------
Question Number 7
System.getProperties().put(
"java.rmi.server.codebase",
"http://www.domain.com/classes/");
Which one of the following is a capability of the above code?
Choice 1
Override CLASSPATH
Choice 2
Register an rmi server on its host system
Choice 3
Set the location of all applets in a web server
Choice 4
Append CLASSPATH
Choice 5
Facilitate dynamic class loading for remote objects
------------------------------------------------------------
Question Number 8
Which one of the following statements is FALSE?
Choice 1
Java supports multi-threaded programming.
Choice 2
Threads in a single program can have different priorities.
Choice 3
Multiple threads can manipulate files and get user input at the same time.
Choice 4
Two threads can never act on the same object at the same time.
Choice 5
Threads are created and started with different methods.
------------------------------------------------------------
Question Number 9
1 public static void main(String[] s) {
2 String n1, n2, n3;
3 n1 = "n1";
4 n2 = "n2";
5 n3 = "n3";
6 {
7 String n4 = "inner";
8 n2 = n1;
9 }
10 n3 = null;
11 }
How many instances of the String will be eligible for garbage collection after line 10 in the above code snippet is executed?
Choice 1
0
Choice 2
1
Choice 3
2
Choice 4
3
Choice 5
The code will not compile.
------------------------------------------------------------
Question Number 10
Which code declares class A to belong to the mypackage.financial package?
Choice 1
package mypackage;
package financial;
Choice 2
import mypackage.*;
Choice 3
package mypackage.financial.A;
Choice 4
import mypackage.financial.*;
Choice 5
package mypackage.financial;
------------------------------------------------------------
Question Number 11
How can a MediaTracker object inform multiple threads that file downloads are complete?
Choice 1
Invoke notifyAll()
Choice 2
Invoke ThreadGroup.notify() on the parent ThreadGroup.
Choice 3
Invoke notify()
Choice 4
Create a MediaLoaded Event
Choice 5
The MediaTracker should call destroy()
------------------------------------------------------------
Question Number 12
What code declares a two dimensional array of integers called "intArray"?
Choice 1
int intArray[] = {int intArray[]};
Choice 2
int intArray{int intArray[]};
Choice 3
int **intArray;
Choice 4
two dimensional arrays are not allowed in java
Choice 5
int intArray[][];
------------------------------------------------------------
Question Number 13
public class MailChecker extends Thread {
static Mailbox myMail;
public MailChecker() { start(); }

public void run() {
while( true ) {
if (myMail.newMsg) {
System.out.println(myMail.msg);
myMail.newMsg = false;
}
try {
sleep(50);
} catch(InterruptedException e ) {}
}
}
}

class Mailbox {
public Boolean newMsg;
public String msg;
}
What problem would cause the above code to execute INCORRECTLY?
Choice 1
Sleeping only 50 milliseconds will use too much CPU cycles.
Choice 2
Access to myMail is not thread safe.
Choice 3
There could be data corruption with the myMail attribute.
Choice 4
Class Mailbox doesn't encapsulate its data with accessors.
Choice 5
Modifying the myMail static instance will cause an exception.
------------------------------------------------------------
Question Number 14
double x = 0, y = 5.4324;

try {
System.out.println( (y/x) );
} catch (Exception e) {
System.out.println("Exception");
} catch (Throwable t) {
System.out.println("Error");
}
What is the output of the above code?
Choice 1
-1
Choice 2
0
Choice 3
Error
Choice 4
Infinity
Choice 5
Exception
------------------------------------------------------------
Question Number 15
How do you get a reference to the clipboard?
Choice 1
java.awt.datatransfer.Clipboard.getDesktopClipboar d()
Choice 2
new java.awt.datatransfer.Clipboard()
Choice 3
Java 1.1.x can't get access to the clipboard.
Choice 4
java.awt.Toolkit.getDefaultToolkit().getSystemClip board()
Choice 5
System.lang.ClipBoard
------------------------------------------------------------
Question Number 16
When do you set a thread as a daemon?
Choice 1
To access to the System and Runtime objects directly
Choice 2
When the thread will execute native methods.
Choice 3
For a utility thread that will stop running when the application has completed
Choice 4
To make the thread available to any other object created in the java virtual machine
Choice 5
To set the thread's priority as low as possible.
------------------------------------------------------------
Question Number 17
To access runtime type information for a class, array, or primitive datatype, you can use which one of the following classes?
Choice 1
Runtime
Choice 2
System
Choice 3
ClassLoader
Choice 4
Object
Choice 5
Class
------------------------------------------------------------
Question Number 18
java.util.Hashtable ht = new java.util.Hashtable();
java.util.Vector v = new java.util.Vector();
for(int i = 0; i < 10; i++) {
v.addElement( new Integer( i ) );
ht.put( new Integer( i ), v );
}
Which code segment will print the keys and elements of the Hashtable above?
Choice 1
Enumeration e = ht.keys();
for(int i=0; i < ht.size(); i++) {
Object o = e.nextElement();
System.out.print(o + " = " + ht.get(o) );
}
Choice 2
for(Enumeration e=ht.elements(); e.hasMoreElements();) {
Integer i = (Integer) e.nextElement();
System.out.print(i.toString() + " = " + ht.get(i) );
}
Choice 3
for(Enumeration e=v.elements(); e.hasMoreElements();)
Integer i = (Integer) e.nextElement();
System.out.print(i.toString() + " = " + v.get(i.intValue()) );
}
Choice 4
for(int i=0; i < ht.size(); i++)
System.out.print(ht.elementAt(i,0) + " = " + ht.elementAt(i,1) );
Choice 5
int j=0;
while(j < ht.size()) {
int i = (int) ht.elementAt(j);
System.out.print(i + " = " + ht.get(i));
j++;
}
------------------------------------------------------------
Question Number 19
import java.sql.*;

Additional code here

Connection con = DriverManager.getConnection(url);
String s = "call proc(?,?,?,?)";
CallableStatement cs = con.prepareCall(s);
cs.setInt(1,1);
cs.setInt(2,2);
cs.setInt(3,3);
cs.registerOutParameter(4,java.sql.TYPES.INTEGER);
Referring to the above, which command executes procedure proc(), which includes two INSERT SQL statements and one OUT parameter?
Choice 1
ResultSet = cs.runQuery()
Choice 2
cs.execute()
Choice 3
cs.executeQuery()
Choice 4
cs.prepareCall().execute()
Choice 5
con.getConnection(cs)
------------------------------------------------------------
Question Number 20
public int increment() {
counter++;
out.write(counter);
catch(Exception e) {}
return counter;
}
Referring to the above, what is missing from method increment()?
Choice 1
A "finally" code block must follow the catch block.
Choice 2
"counter" must be declared inside increment()
Choice 3
There is no "try" block enclosing the code before the "catch" block.
Choice 4
This method should be synchronized.
Choice 5
An explicit "catch" block catching a java.io.IOException is required.
------------------------------------------------------------
Question Number 21
int shifter(int[] array, int arrayLength) {
synchronized (array) {
for(int i=1;i<arrayLength;i++) {
array[i-1] = array[i];
}
}
}
Referring to the above, what is the purpose of the "synchronized (array)" code block?
Choice 1
It forces the thread to obtain the monitor for "array" before continuing.
Choice 2
It ensures that any threads created in the code block begin execution in the "array" object.
Choice 3
It is the same as declaring shifter() as synchronized.
Choice 4
It sets all methods of the object to synchronized while the code block executes.
Choice 5
It forces the virtual machine to treat "array" as a static object.
------------------------------------------------------------
Question Number 22
package B;

public class A {
int getSquare(int i) {
return i*i;
}
}
Referring to the above, what classes can access method getSquare() in class A?
Choice 1
Class A.
Choice 2
Class A and classes in package B only.
Choice 3
Class A, all subclasses of A, and classes in package B only.
Choice 4
Class A and its subclasses only.
Choice 5
Class A, all subclasses of A, classes in package B, and all classes in sub-packages of B.
------------------------------------------------------------
Question Number 23
Which one of the following operators has a higher precedence than the modulus operator, % ?
Choice 1
*
Choice 2
. (dot)
Choice 3
-
Choice 4
/
Choice 5
+
------------------------------------------------------------
Question Number 24
public void printIt(String txt) {
java.util.StringTokenizer st = new java.util.StringTokenizer(txt);
while (st.hasMoreTokens()) {
System.out.println(st.nextToken());
}
}
Referring to the above, what is the result when the following statement is invoked? printIt(" Hello\n World\t!" );
Choice 1
The following is outputted:
Hello
World
!
Choice 2
The following is outputted:
HelloWorld!
Choice 3
java.util.NoSuchElementException is thrown.
Choice 4
The following is outputted:
Hello

World
!
Choice 5
The following is outputted:
Hello

World!
------------------------------------------------------------
Question Number 25
How can you store a copy of an object at the same time other threads may be changing the object's properties?
Choice 1
Give the thread performing storage a higher priority than other threads.
Choice 2
Override writeObject() in ObjectOutputStream to make it synchronized.
Choice 3
Implement java.io.Externalizable instead of java.io.Serializable.
Choice 4
Clone the object in a block synchronized on the object and serialize the clone.
Choice 5
Nothing special, since all ObjectOutputStream methods are synchronized.
------------------------------------------------------------
Question Number 26
class A {
private int x=0;
public synchronized void update() { x++; }
public class B {
public synchronized void update() { x++; }
}
}
Referring to the above, what happens if the following code is executed?

A a = new A();
A.B b = a.new B();
b.update();
Choice 1
There is a compiler error
Choice 2
"b" acquires both the monitors of "a" and "b" and increment "x"
Choice 3
"a" acquires its own monitor and update "x"
Choice 4
"b" acquires its own monitor and then increment "x"
Choice 5
"b" acquires the monitor of "a" and increment "x"
------------------------------------------------------------
Question Number 27
Which code segment listens for a socket connection?
Choice 1
(new MulticastSocket(8080)).joinGroup();
Choice 2
Socket socket = new Socket();
Choice 3
Socket socket = HttpURLConnection.open(8080);
Choice 4
Socket socket = (new ServerSocket(8080)).accept();
Choice 5
Socket socket = SocketImpl.listen(8080);
------------------------------------------------------------
Question Number 28
int count = 0;
do {
System.out.println("Line " + count);
count++;
} while(count < X );
What value for X above will print EXACTLY 10 lines to standard output?
Choice 1
0
Choice 2
5
Choice 3
9
Choice 4
10
Choice 5
11
------------------------------------------------------------
Question Number 29
import java.awt.*;
class A extends Frame implements ActionListener,
WindowListener {
public A() {
Button button1 = new Button("Click Me");
button.addActionListener(this);
add(button1);
show();
}
public actionPerformed(ActionEvent e) {}
void b1() { return; }
}
Referring to the above, what statement is added to actionPerformed() so that b1() is invoked for a click on button1?
Choice 1
b1();
Choice 2
if(e.getActionCommand().equals("button1")) b1();
Choice 3
if(e.target == button1) b1();
Choice 4
if(e.getSource().equals(button1)) b1();
Choice 5
if(e.type == ButtonAction) b1();
------------------------------------------------------------
Question Number 30
-------------------
| |
-------------------
The widget shown above is similar to which standard java.awt class?
Choice 1
TextBox
Choice 2
Label
Choice 3
TextField
Choice 4
TextArea
Choice 5
Entry
------------------------------------------------------------
Question Number 31
String s = "Chase the ball.";
StringBuffer sb = new StringBuffer(s);
Which code segment below produces a string equal to "Chase kicked the ball." using s and sb as shown above?
Choice 1
sb.delete(6,15);
sb.append("kicked the ball.");
s = sb.toString();
Choice 2
sb.insert(6,"kicked ");
s = sb.toString();
Choice 3
sb.substring(0,6);
sb.append("kicked the ball.");
s = sb.toString();
Choice 4
sb.append(8,"kicked ");
s = sb.toString();
Choice 5
sb.append(6,"kicked ");
s = sb.toString();
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Question Number 32
Which code segment loads and plays a sound in an applet?
Choice 1
getAppletContext().getAudioClip( new URL( getDocumentBase().toString() +
"/jaws.wav" ) ).start();
Choice 2
Play( getDocumentBase(),"jaws.wav" );
Choice 3
getAudioClip( new URL( getDocumentBase().toString() + "/jaws.wav" ) ).play();
Choice 4
getAppletContext().playAudio( new URL( getDocumentBase().toString() + "/jaws.wav" ) );
Choice 5
Play( getDocumentBase().toString() + "/jaws.wav" );
------------------------------------------------------------
Question Number 33
int shifter(int[] array, int arrayLength) {
for(int i=1;i<arrayLength;i++) {
array[i-1] = array[i];
}
}
Referring to the above, how do you prevent other threads from changing data in "array" while method shifter() is executing?
Choice 1
Declare shifter as synchronized
Choice 2
Add "synchronized" to the "array[i-1] = array[i];" statement
Choice 3
Declare "array" as static
Choice 4
Enclose all code in all classes changing "array" in a synchronized (array) code block
Choice 5
Call wait() before executing the for-loop
------------------------------------------------------------
Question Number 34
Which socket class can send packets unreliably?
Choice 1
java.net.DatagramSocket()
Choice 2
java.net.URL()
Choice 3
java.net.URLConnection()
Choice 4
java.net.Socket()
Choice 5
java.net.UDPSocket()
------------------------------------------------------------
Question Number 35
if(check4Biz(str).equals("Y") || count == 2) {}
Referring to the above, what datatype is returned by method check4Biz()?
Choice 1
String
Choice 2
byte
Choice 3
Boolean
Choice 4
char
Choice 5
int
------------------------------------------------------------
Question Number 36
int count=0, i=0;
do {
count *= i;
i++;
if(count == 1) continue;
count++;
} while(i<3);
Referring to the above, what is the value of "count" after execution?
Choice 1
0
Choice 2
3
Choice 3
4
Choice 4
6
Choice 5
10
------------------------------------------------------------
Question Number 37
1: Date myDate = new Date();
2: DateFormat dateFormat = DateFormat.getDateInstance();
3: String myString = dateFormat.format(myDate);
4: System.out.println( "Today is " + myString );
How can you change line 2 above so that the date is displayed in the same format used in China?
Choice 1
DateFormat.setLocale( java.util.Locale.CHINA );
DateFormat dateFormat = DateFormat.getDateInstance();
Choice 2
DateFormat dateFormat = DateFormat.getDateInstance(
DateFormat.SHORT, java.util.Locale.CHINA);
Choice 3
java.util.Local locale = java.util.Locale.getLocale("China");
DateFormat dateFormat = DateFormat.getDateInstance( locale );
Choice 4
DateFormat dateFormat = DateFormat.getDateInstance();
dateFormat.setLocale( java.util.Locale.CHINA );
Choice 5
java.util.Local locale = java.util.Locale.getLocale( java.util.Locale.CHINA );
DateFormat dateFormat = DateFormat.getDateInstance( locale );
------------------------------------------------------------
Question Number 38
Which one of the following is true of a java.text.Collator object's "strength"?
Choice 1
It sets the java.util.Locale used for string comparisons.
Choice 2
It sets whether CollationKey or String objects are compared.
Choice 3
It indicates if string comparisons use ASCII or Unicode.
Choice 4
It determines the degree of comparison used to rank strings.
Choice 5
It is a multiplier for difference values between strings.
------------------------------------------------------------
Question Number 39
class PrimeThread extends Thread {
long minPrime;
long result;

PrimeThread(long minPrime) {
this.minPrime = minPrime;
}
public void run() {
// compute primes larger than minPrime
// . . .
}
}
Referring to the above, which code segment could create and start PrimeThread?
Choice 1
PrimeThread p = new PrimeThread();
p.run();
Choice 2
Runnable r = new Runnable( PrimeThread(143) );
r.start();
Choice 3
(new PrimeThread(143)).start();
Choice 4
Thread p = new Thread(new PrimeThread(143));
p.run();
Choice 5
PrimeThread(143).run();
------------------------------------------------------------
Question Number 40
big_loop: for(int i = 0; i < 3; i++) {
try {
for(int j = 0; j < 3; j++) {
if (i==j) continue;
else if (i>j) continue big_loop;
System.out.print("A ");
}
}
finally {
System.out.print("B ");
}
System.out.print("C ");
}
What is the output from the program above?
Choice 1
A B C A B C A B C
Choice 2
A A A B C A A A B C A A A B C
Choice 3
A A B C B B
Choice 4
A A B B C A C A
Choice 5
None. The program will enter into an infinite loop.
------------------------------------------------------------

[coderzone]

Hey very nice collection of questions

[devom]

Hi,
the questions are really good. but plz provide their answers too as early as possible.........

[shabbir]

Sorry but we dont want to provide the spoilers here so that everyone can try them out. If you are unable to solve any or need any help try creating a new thread with the concerned question instead.

[Creator]

Hey good Collection of questions. Thank you..