Odesk Test Java Technologies

Java Technologies

  

Question:

Which of the following is the correct syntax for suggesting that the JVM perform garbage collection?

	a.	System.setGarbageCollection();
	b.	System.out.gc();
	c.	System.gc();
	d.	System.free();

Question:

Choose all valid forms of the argument list for the FileOutputStream constructor shown below:

	a.	FileOutputStream( FileDescriptor fd )
	b.	FileOutputStream( String n, boolean a )
	c.	FileOutputStream( boolean a )
	d.	FileOutputStream()
	e.	FileOutputStream( File f )

Question:

What will happen when this code is compiled and run? (The employee table has only 1 column) import java.sql.*; public class X {     X() {         try {         Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");         Connection c = DriverManager.getConnection("jdbc:odbc:MedSol","","");         Statement         s = c.createStatement();         ResultSet r = s.executeQuery("SELECT * from Employee");     c.close();     while(r.next()) {     System.out.println(r.getString(1));     }     }         catch(Exception e)         {         e.printStackTrace();         }         } public static void main(String str[]) {     new X(); } }

	a.	All the values of column one are printed
	b.	Nothing is printed
	c.	The code will fail to compile
	d.	The code will throw an exception as records are being printed after the connection is closed

Question:

Which of the following statements are correct with regard to Polymorphism?

	a.	Polymorphism is a method in which a class can exist in multiple forms
	b.	Polymorphism is a method in which a class can exist in only two forms
	c.	Polymorphism is a method in which different instances of an object displays different behavior
	d.	Polymorphism is a method in which different instances of an object displays same behavior

Question:

Can ServerSocket be used with UDP?

	a.	Yes
	b.	No

Question:

Which sequence will be printed when the following program is run? import java.util.*; public class Test { public static void main(String str[]) { List l = new ArrayList(); l.add(''1''); l.add(''2''); l.add(1,''3''); System.out.println(l); } }

	a.	[1, 3, 2]
	b.	[1, 3, 1]
	c.	[1, 1, 3]
	d.	[1, 1, 2]
	e.	This code will generate an error

Question:

What is Abstraction?

	a.	An act of representing essential features without including details or working methodology
	b.	An act of representing essential features along with the details or working methodology
	c.	An act of acquiring properties of some other object
	d.	An ability to be present in more than one form

Question:

What should be the replacement of "//ABC" in the following code? class Krit {     String str= new String("OOPS !!! JAVA");     public void KritMethod(final int iArgs)     {       int iOne;       class Bicycle       {         public void sayHello()         {           //ABC         }       }     }     public void Method2()     {       int iTwo;     } }

	a.	System.out.print(str);
	b.	System.out.print(iOne);
	c.	System.out.print(iTwo);
	d.	System.out.print(iArgs);

Question:

What will be the output of this program? public class Test { public static void main (String args[]) { int a, b; a = 2; b = 0; System.out.println (g (a, new int[] {b})); } public static int g (int a, int b[]) { b[0] = 2 * a; return b[0]; } }

	a.	0
	b.	1
	c.	An exception will occur
	d.	4

What would happen on trying to compile and run the following code? public class Test { public static void main (String args[]) { int iRand; iRand = Math.random(); System.out.println(iRand); } }

	a.	A compilation error about random being an unrecognized method will occur
	b.	A random number between 0 and 1
	c.	A random number between 1 and 10
	d.	A compilation error referring to a cast problem

Question:

Which of these interfaces is the most applicable when creating a class that associates a set of keys with a set of values?

	a.	Collection
	b.	Set
	c.	Map
	d.	SortedSet

Question:

One method in your application needs to be synchronized. Which of the following options are correct for synchronization?

	a.	public synchronized void Process(void){}
	b.	public void Process(){         synchronized(this){         }     }
	c.	public void synchronized Process(){}
	d.	public synchronized void Process(){}

Question:

What would be the result of compiling and running the following code class? public class Test { public static void main (String args[]) { Test t = new Test (); t.start (); } public void start () { int i = 2; int j = 3; int x = i & j; System.out.println (x); } }

	a.	The code will not compile
	b.	The code will compile but will give runtime error
	c.	The code will compile and print 2
	d.	The code will compile and print 1

Question:

Which of the following are not Java keyword?

	a.	strictfp
	b.	for
	c.	wait
	d.	while
	e.	try

What would happen on trying to compile and run the following code? public class Quest { int i=0; public static void main(String argv[]) { } Quest() { top: while(i <2) { System.out.println(i); i++; continue top; } } }

	a.	The code will compile but no output at runtime
	b.	The code will compile and output of 0
	c.	The code will compile and output of 0 followed by 1
	d.	The code will not compile as a target label cannot appear before the corresponding continue or break statement

Question:

What will be the output of the following program? public class Test {     public static void main (String args[ ])     {         B o = new A ();         System.out.println (o.content ());     }     public String content () throws Exception     {         throw new Exception (''This is an exception on this.content ()'');     }     private static class B     {         public String content ()         {         return ''B'';         }      }      private static class A extends B      {         public String content ()         {            return ''A'';         }      } }

	a.	The code will compile but will fail to run
	b.	The code will compile and on running, it will print ''A''
	c.	The code will fail to compile
	d.	The code will compile and on running, it will print ''B''

Question:

Which of the following will ensure that garbage collection runs?

	a.	System.free()
	b.	Runtime.gc()
	c.	Object.gc()
	d.	System.gc()
	e.	None of the above

Question:

You have a class called TwoTyre. Its main method is as follows: public static void main(String bicycle[]) {         System.out.println(bicycle[0]); } On the command line you typed: java TwoTyre one two what would be the result?

	a.	one
	b.	two
	c.	TwoTyre
	d.	None of the above

Question:

What is the return type of the method ceil(double) from the Math class?

	a.	int
	b.	float
	c.	double
	d.	Integer
	e.	Double

Question:

What is the java.net.IDN class in 1.6?

	a.	Methods to resolve integrated domain names (IDNs), such domain names are special embedded names
	b.	Methods to swap bytes between network byte order and host byte order
	c.	Methods to convert internationalized domain names (IDNs) between a normal Unicode representation and an ASCII Compatible Encoding (ACE) representation
	d.	This class does not exist
	e.	None of the above

Question:

How does the set collection deal with duplicate elements?

	a.	Duplicate values will cause an error at compile time
	b.	A set may contain elements that return duplicate values from a call to the equals method
	c.	An exception is thrown if you attempt to add an element with a duplicate value
	d.	The add method returns false if you attempt to add an element with a duplicate value

Question:

What is the superclass of java.net.DatagramSocket?

	a.	java.net.Socket
	b.	java.net.UDPSocket
	c.	java.net.SocketInterface
	d.	java.lang.Object
	e.	None of the above

Question:

What would happen on trying to compile and run the following code? class House { public final void MaintainMethod() { System.out.println("MaintainMethod"); } } public class Building extends House { public static void main(String argv[]) { House h = new House(); h.MaintainMethod(); } }

	a.	A runtime error will occur because class House is not defined as final
	b.	Successful compilation and output of "MaintainMethod" at run time
	c.	A compilation error indicating that a class with any final methods must be declared final itself
	d.	A compilation error indicating that you cannot inherit from a class with final methods

Question:

Which of the following is a short circuit operator?

	a.	&&
	b.	||
	c.	|
	d.	&

Question:

What will be the output when this code is compiled and run? public class Test { static int a; int b; public Test () { int a, b, c; a = b = c = 20; System.out.println (a); } public static void main (String args[]) { new Test (); } }

	a.	The code will fail to compile
	b.	True is printed
	c.	Nothing is printed
	d.	20 is printed

Question:

What is printed to the standard output if myMethod() is executed? class MyPoint {   void myMethod() {      int x, y;      x = 5; y = 3;      System.out.print( " ( " + x + ", " + y + " ) " );      switchCoords( x, y );      System.out.print( " ( " + x + ", " + y + " ) " );   }   void switchCoords( int x, int y ) {      int temp;      temp = x;      x = y;      y = temp;      System.out.print( " ( " + x + ", " + y + " ) " );   } }

	a.	(5, 3) (5, 3) (5, 3)
	b.	(5, 3) (3, 5) (3, 5)
	c.	(5, 3) (3, 5) (5, 3)
	d.	No output will be printed

Question:

Which of the following are the methods of the Thread class?

	a.	stay()
	b.	go()
	c.	yield()
	d.	sleep(long millis)

Question:

All class methods in the java.lang package are thread safe. (in 1.5)

	a.	True
	b.	False

Question:

Assuming that val has been defined as an int for the code below, which values of val will result in "Test C" being printed? if( val > 4 ) {    System.out.println("Test A"); }else if( val > 9 ) {    System.out.println("Test B"); }else    System.out.println("Test C");

	a.	val < 0
	b.	val between 0 and 4
	c.	val between 4 and 9
	d.	val > 9
	e.	val = 0
	f.	No values for val will result in "Test C" being printed

Question:

A method can be defined as native to:

	a.	Overcome the limitation of the private scope of a method
	b.	Get to access hardware that Java does not know about
	c.	Write optimized code for performance in a language such as C/C++
	d.	Define a new data type such as an unsigned integer

Question:

Which class contains a method to create a directory?

	a.	File
	b.	DataOutput
	c.	Directory
	d.	FileDescriptor
	e.	FileOutputStream

Question:

What will be the output when this code is compiled and run? public class Test { public Test () { Bar b = new Bar (); Bar b1 = new Bar (); update (b); update (b1); b1 = b; update (b); update (b1); } private void update (Bar bar) { bar.x = 20; System.out.println (bar.x); } public static void main (String args[]) { new Test (); } private class Bar { int x = 10; } }

	a.	The code will fail to compile
	b.	10 10 10 10
	c.	20 20 20 20
	d.	10 20 10 20

Question:

Choose the correct statements:

	a.	An inner class may extend another class
	b.	There are no circumstances where an inner class may be defined as private
	c.	A programmer may only provide one constructor for an anonymous class
	d.	An inner class may be defined as static

Question:

What would happen on trying to compile and run the following code? private class Crack { } public class Manic {     transient int numb;     public static void main(String sparrow[])     { } }

	a.	A Compilation error because an integer cannot be transient
	b.	A Compilation error because transient is not a data type
	c.	A Compilation error because of an erroneous main method
	d.	A Compilation error because class Crack cannot be private

Question:

Which of the following cannot apply to constructors?

	a.	Name same as class name
	b.	Void return type
	c.	Can have parameters
	d.	Overloading

Question:

How many objects are created by the following code? Object a, b, c, d, e; e = new Object (); b = a = e; e = new Object ();

	a.	2
	b.	5
	c.	4
	d.	This code is invalid

Question:

Which of the following statements are true about local inner class within a method?

	a.	It can be marked as static
	b.	It can only access final members of its enclosing class
	c.	It has access to all members of its enclosing class
	d.	None of the above

Question:

What would happen on trying to compile and run the following code? public class MainCls {      public static void main(String argv)      {      System.out.println("My Text");      } }

	a.	A compile error will be generated because 'main' is a reserved word and cannot be used for a class
	b.	"My Text" will be displayed
	c.	The code will compile. A runtime error will occur because 'main' is not properly defined
	d.	The code will compile. A runtime error will occur because constructor is not defined

Question:

Which of the following statements is not correct with regard to threads in Java?

	a.	A call to the wait method causes the calling thread to pause its execution
	b.	The wait and notify methods are defined in the Thread class
	c.	The synchronized keyword can be applied to either a method or a block of code
	d.	Any code that has calls to the wait or notify methods must be synchronized