Sun Certified Java Developer Interview Preparation Guide Download PDF
Sun Certified Java Developer guideline for job interview preparation. Explore list of Sun Certified Java Developer frequently asked questions(FAQs) asked in number of Sun Certified Java Developer interviews. Post your comments as your suggestions, questions and answers on any Sun Certified Java Developer Interview Question or answer. Ask Sun Certified Java Developer Question, your question will be answered by our fellow friends.
20 Sun Certification Questions and Answers:
Table of Contents:
3 :: Explain IF you are remotely logged on to a Solaris machine, What command would you execute?
mt f /dev/rmt/0 status
4 :: Explain Given:
10. class Nav{
11. public enum Direction { NORTH, SOUTH, EAST, WEST }
12. }
13. public class Sprite{
14. // insert code here
15. }
Which code, inserted at line 14, allows the Sprite class to compile?
A. Direction d = NORTH;
B. Nav.Direction d = NORTH;
C. Direction d = Direction.NORTH;
D. Nav.Direction d = Nav.Direction.NORTH;
D:Nav.Direction d = Nav.Direction.NORTH;
6 :: Explain Given:
11. public abstract class Shape {
12. private int x;
13. private int y;
14. public abstract void draw();
15. public void setAnchor(int x, int y) {
16. this.x = x;
17. this.y = y;
18. }
19. }
Which two classes use the Shape class correctly? (Choose two.)
A. public class Circle implements Shape {
private int radius;
}
B. public abstract class Circle extends Shape {
private int radius;
}
C. public class Circle extends Shape {
private int radius;
public void draw();
}
D. public abstract class Circle implements Shape { private int radius;
public void draw();
}
E. public class Circle extends Shape {
private int radius;
public void draw() {/* code here */}
F. public abstract class Circle implements Shape { private int radius;
public void draw() { /* code here */ }
B:public abstract class Circle extends Shape {
private int radius;
}
E:public class Circle extends Shape {
private int radius;
public void draw() {/* code here */}
private int radius;
}
E:public class Circle extends Shape {
private int radius;
public void draw() {/* code here */}
9 :: Explain Given:
1. public class Threads2 implements Runnable {
2.
3. public void run() {
4. System.out.println("run.");
5. throw new RuntimeException("Problem");
6. }
7. public static void main(String[] args) {
8. Thread t = new Thread(new Threads2());
9. t.start();
10. System.out.println("End of method.");
11. }
12. }
Which two can be results? (Choose two.)
A. java.lang.RuntimeException: Problem
B. run.
java.lang.RuntimeException: Problem
C. End of method.
java.lang.RuntimeException: Problem
D. End of method.
run.
java.lang.RuntimeException: Problem
E. run.
java.lang.RuntimeException: Problem
End of method.
D:End of method.
run.
java.lang.RuntimeException: Problem
E:run.
java.lang.RuntimeException: Problem
End of method.
run.
java.lang.RuntimeException: Problem
E:run.
java.lang.RuntimeException: Problem
End of method.
11 :: Explain Given:
1. public class Blip {
2. protected int blipvert(int x) { return 0; }
3. }
4. class Vert extends Blip {
5. // insert code here
6. }
Which five methods, inserted independently at line 5, will compile? (Choose five.)
A. public int blipvert(int x) { return 0; }
B. private int blipvert(int x) { return 0; }
C. private int blipvert(long x) { return 0; }
D. protected long blipvert(int x) { return 0; }
E. protected int blipvert(long x) { return 0; }
F. protected long blipvert(long x) { return 0; }
G. protected long blipvert(int x, int y) { return 0; }
A:public int blipvert(int x) { return 0; }
C:private int blipvert(long x) { return 0; }
E:protected int blipvert(long x) { return 0; }
F:protected long blipvert(long x) { return 0; }
G:protected long blipvert(int x, int y) { return 0; }
C:private int blipvert(long x) { return 0; }
E:protected int blipvert(long x) { return 0; }
F:protected long blipvert(long x) { return 0; }
G:protected long blipvert(int x, int y) { return 0; }
12 :: Tell me What is native keyword and abstract keyword?
Native keyword is prefixed with method name when we want that method to be implemented using a native language like c and c++. So in the class we only declare the method and the definition of the method is in the dll file.
Abstract key word is used to mark a method or a class as logically incomplete. The class which extends this class has to provide the definition of the method or has to declare the derived class as abstract.
We can not declare a native method inside a interface because by declaring a method in an interface we want all the implementers to give definitions to the methods defined. But by declaring a method native we mean that the implementation will come from some native language.
Abstract key word is used to mark a method or a class as logically incomplete. The class which extends this class has to provide the definition of the method or has to declare the derived class as abstract.
We can not declare a native method inside a interface because by declaring a method in an interface we want all the implementers to give definitions to the methods defined. But by declaring a method native we mean that the implementation will come from some native language.
13 :: Explain Which two statements are true? (Choose two.)
A. It is possible for more than two threads to deadlock at once.
B. The JVM implementation guarantees that multiple threads cannot enter into a deadlocked state.
C. Deadlocked threads release once their sleep() methods sleep duration has expired.
D. Deadlocking can occur only when the wait(), notify(), and notifyAll() methods are used incorrectly.
E. It is possible for a single-threaded application to deadlock if synchronized blocks are used incorrectly.
F. If a piece of code is capable of deadlocking, you cannot eliminate the possibility of deadlocking by inserting
invocations of Thread.yield().
A: It is possible for more than two threads to deadlock at once.
F:If a piece of code is capable of deadlocking, you cannot eliminate the possibility of deadlocking by inserting
invocations of Thread.yield().
F:If a piece of code is capable of deadlocking, you cannot eliminate the possibility of deadlocking by inserting
invocations of Thread.yield().
14 :: Explain Given:
1. class Super {
2. private int a;
3. protected Super(int a) { this.a = a; }
4. }
...
11. class Sub extends Super {
12. public Sub(int a) { super(a); }
13. public Sub() { this.a = 5; }
14. }
Which two, independently, will allow Sub to compile? (Choose two.)
A. Change line 2 to:
public int a;
B. Change line 2 to:
protected int a;
C. Change line 13 to:
public Sub() { this(5); }
D. Change line 13 to:
public Sub() { super(5); }
E. Change line 13 to:
public Sub() { super(a); }
C:Change line 13 to:
public Sub() { this(5); }
D:Change line 13 to:
public Sub() { super(5); }
public Sub() { this(5); }
D:Change line 13 to:
public Sub() { super(5); }
17 :: Explain Given:
1. package test;
2.
3. class Target {
4. public String name = "hello";
5. }
What can directly access and change the value of the variable name?
A. any class
B. only the Target class
C. any class in the test package
D. any class that extends Target
C:any class in the test package
18 :: Explain Which Man class properly represents the relationship "Man has a best friend who is a Dog"?
A. class Man extends Dog { }
B. class Man implements Dog { }
C. class Man { private BestFriend dog; }
D. class Man { private Dog bestFriend; }
E. class Man { private Dog<bestFriend>; }
F. class Man { private BestFriend<dog>; }
D:class Man { private Dog bestFriend; }
20 :: Explain What is the result of mounting a file system with thenoatimeoption enabled?
A.It enables the UFS logging
B.It disables the update of file access times
C.It prevents the creation of files larger than 2Gbytes
D.It prevents the user from updating the file modification times
B.It disables the update of file access times