Java Programmer Certification Mock Exam

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Question 1

Which of the following methods are members of the Object class?

a.	join
b.	notify
c.	notifyAll
d.	run
e.	sleep
f.	start
g.	yield
h.	wait

Question 2

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

a.	join
b.	notify
c.	notifyAll
d.	run
e.	sleep
f.	start
g.	yield
h.	wait

Question 3

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

a.	join
b.	notify
c.	notifyAll
d.	resume
e.	run
f.	sleep
g.	start
h.	stop
i.	suspend
j.	yield
k.	wait

Question 4

Which of the following methods name the InterruptedException in its throws clause?

a.	join
b.	notify
c.	notifyAll
d.	run
e.	sleep
f.	start
g.	yield
h.	wait

Question 5

A timeout argument can be passed to which of the following methods?

a.	join
b.	notify
c.	notifyAll
d.	run
e.	sleep
f.	start
g.	yield
h.	wait

Question 6

Which of the following instance methods should only be called by a thread that holds the lock of the instance on which the method is invoked?

a.	join
b.	notify
c.	notifyAll
d.	run
e.	start
f.	wait

Question 7

Which of the following is a checked exception?

a.	IllegalMonitorStateException
b.	IllegalThreadStateException
c.	IllegalArgumentException
d.	InterruptedException
e.	None of the above

Question 8

Which kind of variable would you prefer to synchronize on?

a.	A member variable of a primitive type
b.	A member variable that is an object reference
c.	A method local variable that is a reference to an instance that is created within the method
d.	None of the above

Question 9

synchronized (expression) block

The synchronized statement has the form shown above. Which of the following are true statements?

a.	A compile-time error occurs if the expression produces a value of any reference type
b.	A compile-time error occurs if the expression produces a value of any primitive type
c.	A compile-time error does not occur if the expression is of type boolean
d.	The sychronized block may be processed normally if the expression is null
e.	If execution of the block completes normally, then the lock is released
f.	If execution of the block completes abruptly, then the lock is released
g.	A thread can hold more than one lock at a time
h.	Synchronized statements can be nested
i.	Synchronized statements with identical expressions can be nested

Question 10

Which of the following is a true statement?

a.	The process of executing a synchronized method requires the thread to acquire a lock
b.	Any overriding method of a synchronized method is implicitly synchronized
c.	If any method in a class is synchronized, then the class itself must also be declared using the synchronized modifier
d.	If a thread invokes a static synchronized method on an instance of class A, then the thread must acquire the lock of that instance of class A
e.	None of the above

Question 11

Which of the following thread state transitions model the lifecycle of a thread?

a.	The Dead state to the Ready state
b.	The Ready state to the Not-Runnable state
c.	The Ready state to the Running state
d.	The Running state to the Not-Runnable state
e.	The Running state to the Ready state
f.	The Not-Runnable state to the Ready state
g.	The Not-Runnable state to the Running state

Question 12

Which of the following are true statements?

a.	The Thread.yield method might cause the thread to move to the Not-Runnable state
b.	The Thread.yield method might cause the thread to move to the Ready state
c.	The same thread might continue to run after calling the Thread.yield method
d.	The Thread.yield method is a static method
e.	The behavior of the Thread.yield method is consistent from one platform to the next
f.	The Thread.sleep method causes the thread to move to the Not-Runnable state
g.	The Thread.sleep method causes the thread to move to the Ready state

Question 13

Which of the following will not force a thread to move into the Not-Runnable state?

a.	Thread.yield method
b.	Thread.sleep method
c.	Thread.join method
d.	Object.wait method
e.	By blocking on I/O
f.	Unsuccessfully attempting to acquire the lock of an object
g.	None of the above

Question 14

Which of the following will cause a dead thread to restart?

a.	Thread.yield method
b.	Thread.join method
c.	Thread.start method
d.	Thread.resume method
e.	None of the above

Question 15

When a thread is created and started, what is its initial state?

a.	New
b.	Ready
c.	Not-Runnable
d.	Runnning
e.	Dead
f.	None of the above

Question 16

Which of the following are true statements?

a.	The Thread.run method is used to start a new thread running
b.	The Thread.start method causes a new thread to get ready to run at the discretion of the thread scheduler
c.	The Runnable interface declares the start method
d.	The Runnable interface declares the run method
e.	The Thread class implements the Runnable interface
f.	If an Object.notify method call appears in a synchronized block, then it must be the last method call in the block
g.	No restriction is placed on the number of threads that can enter a synchronized method
h.	Some implementations of the Thread.yield method will not yield to a thread of lower priority

Question 17

Which of the following are true statements?

a.	Thread.MAX_PRIORITY == 10
b.	Thread.MAX_PRIORITY == 5
c.	Thread.NORM_PRIORITY == 5
d.	Thread.NORM_PRIORITY == 3
e.	Thread.NORM_PRIORITY == 0
f.	Thread.MIN_PRIORITY == 1
g.	Thread.MIN_PRIORITY == 0
h.	Thread.MIN_PRIORITY == -5
i.	Thread.MIN_PRIORITY == -10

Question 18

Which of the following are true statements?

a.	A program will terminate only when all daemon threads stop running
b.	A program will terminate only when all user threads stop running
c.	A daemon thread always runs at Thread.MIN_PRIORITY
d.	A thread inherits its daemon status from the thread that created it
e.	The daemon status of a thread can be changed at any time using the Thread.setDaemon method
f.	The Thread.setDaemon method accepts one of two argument values defined by the constants Thread.DAEMON and Thread.USER

Question 19

class A extends Thread {
  public A(Runnable r) {super(r);}
  public void run() {System.out.print("A");}
}
class B implements Runnable {
  public void run() {System.out.print("B");}
}
class C {
  public static void main(String[] args) {
    new A(new B()).start();
}}

What is the result of attempting to compile and run the program?

a.	Prints: A
b.	Prints: B
c.	Prints: AB
d.	Prints: BA
e.	Compile-time error
f.	Run-time error
g.	None of the above

Question 20

class A implements Runnable {
  public void run() {System.out.print(Thread.currentThread().getName());}
}
class B implements Runnable {
  public void run() {
    new A().run();
    new Thread(new A(),"T2").run();
    new Thread(new A(),"T3").start();
}}
class C {
  public static void main (String[] args) {
    new Thread(new B(),"T1").start();
}}

What is the result of attempting to compile and run the program?

a.	Prints: T1T1T1
b.	Prints: T1T1T2
c.	Prints: T1T2T2
d.	Prints: T1T2T3
e.	Prints: T1T1T3
f.	Prints: T1T3T3
g.	Compile-time error
h.	Run-time error
i.	None of the above

Question 21

class AnException extends Exception {}
class A extends Thread {
  public void run() throws AnException {
    System.out.print("A"); throw new AnException();
}}
class B {
  public static void main (String[] args) {
    A a = new A(); a.start(); System.out.print("B");
}}

What is the result of attempting to compile and run the program?

a.	Prints: A
b.	Prints: B
c.	Prints: AB
d.	Prints: BA
e.	Compile-time error
f.	Run-time error
g.	None of the above

Question 22

class A extends Thread {
  public void run() {System.out.print("A");}
}
class B {
  public static void main (String[] args) {
    A a = new A();
    a.start();
    a.start();  // 1
  }
}

What is the result of attempting to compile and run the program?

a.	The program compiles and runs without error
b.	The second attempt to start thread t1 is successful
c.	The second attempt to start thread t1 is ignored
d.	Compile-time error at marker 1
e.	An IllegalThreadStateException is thrown at run-time
f.	None of the above