Java Multithreading Interview Questions

Here are some commonly asked Java multithreading interview questions:

1. What is multithreading in Java?
2. What is the difference between process and thread?
3. What is a daemon thread in Java?
4. What is the difference between wait and sleep in Java?
5. How does synchronization work in Java?
6. What is the volatile keyword in Java?
7. What is the difference between notify and notifyAll in Java?
8. What is the use of the yield method in Java?
9. Can you explain the producer-consumer problem in Java?
10. What is a deadlock in Java? How can it be prevented?
11. Can you explain the difference between the synchronized block and the synchronized method in Java?
12. What is a lock in Java?
13. How can you implement a thread-safe singleton class in Java?
14. Can you explain the Executor framework in Java?
15. What is the difference between the Callable and Runnable interface in Java?
16. What is the difference between a thread and a runnable in Java?
17. What is the purpose of the join method in Java?
18. What is the difference between the wait and join methods in Java?
19. How do you interrupt a thread in Java?
20. Can you explain the use of the Semaphore class in Java?
21. What is a CountDownLatch in Java?
22. Can you explain the differences between the Executor, ExecutorService, and ScheduledExecutorService interfaces in Java?
23. What is the difference between a thread pool and a work queue in Java?
24. Can you explain the use of the Future class in Java?
25. How do you achieve thread-safe iteration in Java?
26. What is the difference between the ThreadLocal and the InheritableThreadLocal classes in Java?
27. What is the purpose of the synchronized collections in Java?
28. What is a Phaser in Java and when is it used?
29. Can you explain the use of the ReentrantLock class in Java?
30. Can you explain the use of the Atomic variables and classes in Java?
31. Can you explain the purpose and use of the CyclicBarrier class in Java?
32. What is a BlockingQueue in Java?
33. Can you explain the use of the FutureTask class in Java?
34. Can you explain the use of the Executors class in Java?
35. Can you explain the difference between the synchronized and Lock classes in Java?
36. What is a ReadWriteLock in Java?
37. Can you explain the difference between the lockInterruptibly and lock methods in Java?
38. What is a Phaser in Java and when is it used?
39. What is a StampedLock in Java and when is it used?
40. Can you explain the use of the ReentrantReadWriteLock class in Java?
41. Can you explain the use of the Semaphore class for controlling concurrency in Java?
42. What is a ThreadPoolExecutor in Java and when is it used?
43. Can you explain the use of the java.util.concurrent package in Java?
44. Can you explain the difference between the Executor and ExecutorService interfaces in Java?
45. Can you explain the use of the ForkJoinPool class in Java?

Advanced Multithreading interview Questions:

1. Can you explain the difference between the synchronized and ReentrantLock classes in Java, and when to use one over the other?
2. Can you explain the use of the synchronized collections and their performance characteristics compared to non-synchronized collections in Java?
3. Can you explain the use of the java.util.concurrent package for controlling concurrency in Java?
4. Can you explain the use of the ForkJoinPool class for parallel processing in Java?
5. Can you explain the use of the CompletableFuture class for asynchronous processing in Java?
6. Can you explain the difference between a CountDownLatch and a CyclicBarrier in Java, and when to use one over the other?
7. Can you explain the use of the java.util.concurrent.locks package for locking and synchronization in Java?
8. Can you explain the use of the Atomic classes and their performance characteristics compared to traditional synchronization techniques in Java?
9. Can you explain the difference between a ThreadLocal and an InheritableThreadLocal in Java, and when to use one over the other?
10. Can you explain the use of the Phaser class for phased concurrent execution in Java?
11. Can you explain the use of the StampedLock class for lock optimization in Java?
12. Can you explain the use of the java.util.concurrent.locks.ReadWriteLock interface for lock optimization in Java?
13. Can you explain the use of the java.util.concurrent.Executor framework for executing tasks in Java?
14. Can you explain the use of the java.util.concurrent.Executors class for creating and managing thread pools in Java?
15. Can you explain the difference between the java.util.concurrent.Executor and java.util.concurrent.ExecutorService interfaces in Java?
16. Can you explain the use of the java.util.concurrent.Future interface for tracking the status of an asynchronous task in Java?
17. Can you explain the use of the java.util.concurrent.Callable interface for executing tasks that return a result in Java?
18. Can you explain the use of the java.util.concurrent.CompletionService interface for executing tasks and processing their results in Java?
19. Can you explain the use of the java.util.concurrent.ConcurrentMap interface for implementing a thread-safe map in Java?
20. Can you explain the use of the java.util.concurrent.ConcurrentNavigableMap interface for implementing a thread-safe, sorted map in Java?