Java Certification Exam

1. ______ is the super interface of the HttpServletRequest interface.

2. Which of the following methods of an Exception class return the details about the exception that has occurred?

3. Which of the following statements truly specifies the characteristics of static methods in Java?

4. What will be the output of the below Java program?

class MyThread extends Thread

{

    MyThread() {}

    MyThread(Runnable r) {super(r); }

    public void run()

    {

        System.out.print(“Inside Thread “);

    }

}

class RunnableDemo implements Runnable

{

    public void run()

    {

        System.out.print(” Inside Runnable”);

    }

}

class ThreadDemo

{ 

    public static void main(String[] args)

    {

        new MyThread().start();

        new MyThread(new RunnableDemo()).start();

    }

}

5. Which of the following interface does not inherit from the Collection interface? 

6. Which of the following statements are true regarding a constructor in a class?

7. Identify the shortest manner in which you can declare a Java annotation

8. All the methods of the _____________ class are inherited by the Exception class as the former is the super class of all the exceptions and errors in the Java language. 

9. ServletConfig Interface

10. In Servlet which Method Returns the client IP address

11. Which is the most suitable data-structure to store small amount of data for rapid access that need not be sorted or checked for uniqueness?

12. Which class represents the socket used by both the client and server for communicating data over TCP/IP? 

13. Which of the following statements correctly defines an immutable class?

14. Check the following

interface Base

{

    boolean m1 ();

    byte m2(short s);

}

which two code fragments will compile?

1. interface Base2 implements Base { }
2. abstract class Class2 extends Base

              { public boolean m1( ){ return true; }}

3. abstract class Class2 implements Base { }
4. abstract class Class2 implements Base

             { public boolean m1( ){ return (7 > 4); }}

5. abstract class Class2 implements Base

               { protected boolean m1( ){ return (5 > 7) }}

15. If private members are to be called outside the class, which is a good alternative?

16. The ability for programmers to use the same written and debugged existing class

17. What will be the output of the following program?

public class UseGenerics {

    public static void main(String args[]){ 

        MyGen<Integer> m = new MyGen<Integer>(); 

        m.set(“merit”);

        System.out.println(m.get());

    }

}

class MyGen<T>

{

    T var;

    void  set(T var)

    {

        this.var = var;

    }

    T get()

    {

        return var;

    }

}

18. A servlet-mapping element specifies ______. 

19. ______________ represents the need of information in the program without presenting the details.

20. Which among the following is true?

21. Which member can never be accessed by inherited classes?

22. Match the methods of the HttpServletRequest interface methods with their corresponding description.

23. Which of the statement will compile with error
24. A) if (zone.equals(“East”)) {

shippingCost = weight * 0.23f;

}

B) if(rate = 100) {

…

}

C) if(rate = = 100) {

…

}

D) None of the above

24. Which switch statement will give the error

A) switch (zone) {

              case 5:

                     shippingCost = weight * 0.23f;

                    break;

              case 6:

                    shippingCost = weight * 0.23f;

                    break;

               default:

                     shippingCost = weight * 0.25f;

}

B) switch (zone) {

                case 5:

                case 6:

                     shippingCost = weight * 0.23f;

                     break;

                default:

                     shippingCost = weight * 0.25f;

}

C) switch (zone) {

              default:

                  shippingCost = weight * 0.25f;

                  break;

         case 5:

         case 6:

             shippingCost = weight * 0.23f;

             break;

}

D) None of them

25. Which of the following for loop statement is wrong

A) for (int i = 1; i <= 10; i++) {

}

B) for (int i = 1,j=10; i <= 10; i++,j–) {

}

C) for (int i = 1,j=10; i <= 10;j<=0; i++,j–) {

}

D) None of above

26. Which of the following statement is wrong

A) do < statement>

 while (<  boolean-expression >);

B) while (<boolean-expression>)

 < statements >;

C) for (< dataType variabl e> : <collection/array> );

D) while (<boolean-expression>)

do <statement>;

27. What is the output of the following program?

public class JavaApplication2

{

    public static void main(String[] args)

    {

        List<String> list1 = new LinkedList<>();

        list1.add(“Kodnest”);

        list1.add(“Best”);

        list1.add(“Kodnest”);

        list1.add(“KBK”);

        list1.add(“KodnestBestKodnest”);

        List<String> list2 = new LinkedList<>();

        list2.add(“Kodnest”);

        list1.removeAll(list2);

        for (String temp : list1)

            System.out.printf(temp + ” “);

        System.out.println();

    }

}

28. What will be the result of the expression 13 & 25?

29. Which keyword is used for passing current object to a method

30. The concept of multiple inheritances is implemented in Java by

I. Extending two or more classes.

II. Extending one class and implementing one or more interfaces.

III. Implementing two or more interfaces.

31. Java source code compiled into

32. Which of the following statements are valid array declaration ?

A. int number( );

B. float average[ ];

C. double[ ] marks;

D. counter int[ ];

33. What will be the output of the following program?

public class ExamQuestion6

{

    static int x;

    boolean catch( )

    {

        x++;

        return true;

    }

    public static void main(String[] args)

    {

        x=0;

        if ((catch( ) | catch( )) || catch( ))

            x++;

        System.out.println(x);

    }

}

34. Which statement is true?

35. You want subclasses in any package to have access to members of a superclass. Which is the most restrictive access that accomplishes this objective?

36. What will be the output of the program?

int i = 1, j = 10;

do

{

    if(i > j)

    {

        break;

    }

    j–;

} while (++i < 5);

System.out.println(“i = ” + i + ” and j = ” + j);

37. Which statement is true?

38. What will be the output of the program?

class Exc0 extends Exception {  }

 class Exc1 extends Exc0 {  } /* Line 2 */

 public class Test

 {

                public static void main(String args[ ])

        {

                try {

                throw new Exc1( ); /* Line 9 */

                }

            catch (Exc0 e0) /* Line 11 */

           {

            System.out.println(“Ex0 caught”);

           }

           catch (Exception e)

           {

             System.out.println(“exception caught”);

           }

        }

}

39. What will be the output of the program?

public class Foo

{

   public static void main(String[ ] args)

   {

      try{

         return;

            }

    finally {

         System.out.println( “Finally” );

        }

     }

}

40. When a user types the URL

http://www.javaprepare.com/scwd/index.html

Which HTTP request gets generated. Select one correct answer.

41. Which two packages contain the classes and interfaces that are required to build servlets?

42. HttpSession Interface

43. Which error will be produced if private members are accessed?

44. What is the output of the following program?

public class Test

{

    public Test()

    {

        System.out.printf(“1”);

        new Test(10);

        System.out.printf(“5”);

    }

    public Test(int temp)

    {

        System.out.printf(“2”);

        new Test(10, 20);

        System.out.printf(“4”);

    }

    public Test(int data, int temp)

    {

        System.out.printf(“3”);

    }

    public static void main(String[] args)

    {

        Test obj = new Test();  

    }     

}

45. The _____ interface provides various methods to configure a servlet, before processing the data requested by the client.

46. What will be the order of output of the program?

What is the output of the following program?

public class Test

{

    public static void main(String[] args)

    {

        int value = 554;

        String var = (String)value;  //line 1

        String temp = “123”;

        int data = (int)temp; //line 2

        System.out.println(data + var);

    }

}

48. Number of threads in below java program is

public class ThreadExtended extends Thread {

            public void run() {

                        System.out.println(“\nThread is running now\n”);

            }

            public static void main(String[] args) {

                        ThreadExtended threadE = new ThreadExtended();

                        threadE.start();

            }

}

49. Which of the following is not the Java keyword?

50. Which function among the following can’t be accessed outside the class in java in same package?

What is the output of the following program?

import java.io.IOException;

class Derived 

{

    public void getDetails() throws IOException //line 23

    {

        System.out.println(“Derived class”);

    }

}

public class Test extends Derived

{

    public void getDetails() throws Exception //line 24

    {

        System.out.println(“Test class”);

    }

    public static void main(String[] args) throws IOException //line 25

    {

        Derived obj = new Test();

        obj.getDetails();

    }

}

What is the Output of following Java Program?

import java.util.ArrayList;

import java.util.Collections;

import java.util.Iterator;

class Demo {

public void show()

    {

        ArrayList<String> list = new ArrayList<String>();

        list.add(“banana”);

        list.add(“apple”);

        Iterator itr = list.iterator();

        Collections.sort(list);

        while (itr.hasNext()) {

            System.out.print(itr.next() + ” “);

        }

    }

} public class Main {

public static void main(String[] args)

    {

        Demo demo = new Demo();

        demo.show();

    }

}

Which technique is not used to copy one array to another?

What is the output of the following Java program?

public class ThreadDemo implements Runnable

{

            private int x=0;

            private int y=0;

            public static void main(String [] args)

            {

                        ThreadDemo obj = new ThreadDemo();

                        (new Thread(obj)).start(); /*Line 8*/

                        (new Thread(obj)).start(); /*Line 8*/

            }

            public synchronized void run () /*Line 11*/

            {

                        for (int i=0;i<10;i++) /*Line 13*/

                        {

                          x++;

                          y++;

                         System.out.println(“x = “ +x+” ; y = “+y);

                        }

            }

}

55. Assume the following method is properly synchronized and called from a thread A on an object B: wait(2000); After calling this method, when will the thread A become a candidate to get another turn at the CPU?

56. What is the priority of the thread in the following Java Program?

class multithreaded_programing

    {

        public static void main(String args[])

        {

            Thread t = Thread.currentThread();

            System.out.println(t);       

        }

    }

Predict the output of the following program.

abstract class demo

{

    public int a;

    demo()

    {

        a = 10;

    }

    abstract public void set();

    abstract final public void get();

}

class Test extends demo

{

    public void set(int a)

    {

        this.a = a;

    }

    final public void get()

    {

        System.out.println(“a = ” + a);

    }

    public static void main(String[] args)

    {

        Test obj = new Test();

        obj.set(20);

        obj.get();

    }

}

What will be the output of the program?

class Test

{

    public static void main(String [] args)

    {

        Test p = new Test();

        p.start();

    }

    void start()

    {

        boolean b1 = false;

        boolean b2 = fix(b1);

        System.out.println(b1 + ” ” + b2);

    }

    boolean fix(boolean b1)

    {

        b1 = true;

        return b1;

    }

}

What are valid statements for yield method?

Which of the following tag can be used to print the value of an expression?