JAVA INTERVIEW QUESTIONS - MULTI THREADING
MULTI THREADING
1) What are the two types of multitasking?
Ans : 1.process-based
2.Thread-based
2) What are the two ways to create the thread?
Ans: 1.by implementing Runnable
2.by extending Thread
3) What is the signature of the constructor of a thread class?
Ans: Thread(Runnable threadob,String threadName)
4) What are all the methods available in the Runnable Interface?
Ans : run()
5) What is the data type for the method isAlive() and this method is
available in which class?
Ans: boolean, Thread
6) What are all the methods available in the Thread class?
Ans : 1.isAlive()
2.join()
3.resume()
4.suspend()
5.stop()
6.start()
7.sleep()
8.destroy()
7) What are all the methods used for Inter Thread communication and what is the class in which these methods are defined?
Ans :1. wait(),notify() & notifyall()
2. Object class
8) What is the mechanisam defind by java for the Resources to be used by only one Thread at a time?
Ans: Synchronisation
9) What is the procedure to own the moniter by many threads?
Ans: not possible
10) What is the unit for 1000 in the below statement?
ob.sleep(1000)
Ans: long milliseconds
11) What is the data type for the parameter of the sleep() method?
Ans: long
12) What are all the values for the following level?
max-priority
min-priority
normal-priority
Ans : 10,1,5
13) What is the method available for setting the priority?
Ans : setPriority()
14) What is the default thread at the time of starting the program?
Ans: main thread
15) The word synchronized can be used with only a method.
True/ False
Ans: False
16) Which priority Thread can prompt the lower primary Thread?
Ans: Higher Priority
17) How many threads at a time can access a monitor?
Ans: one
18) What are all the four states associated in the thread?
Ans: 1. new 2. runnable 3. blocked 4. dead
19) The suspend()method is used to terminate a thread?
True /False
Ans: False
20) The run() method should necessary exists in clases created as subclass of thread?
True /False
Ans: True
21) When two threads are waiting on each other and can't proceed the programme is said to be in a deadlock?
True/False
Ans: True
22) Which method waits for the thread to die?
Ans : join() method
23) Which of the following is true?
1) wait(),notify(),notifyall() are defined as final & can be called only from with in a synchronized method
2) Among wait(),notify(),notifyall() the wait() method only throws IOException
3) wait(),notify(),notifyall() & sleep() are methods of object class
1
2
3
1 & 2
1,2 & 3
Ans : D
24) Garbage collector thread belongs to which priority?
Ans: low-priority
25) What is meant by timeslicing or time sharing?
Ans: Timeslicing is the method of allocating CPU time to individual threads in a priority schedule.
26) What is meant by daemon thread? In Java runtime, what is it's role?
Ans: Daemon thread is a low priority thread which runs intermittently in the background doing the garbage collection operation for the java runtime system.