Java programming language provides the Concurrency API which provides a high-level threading facility that is easier to use compared to the low-level threading facility using Thread and Runnable. Though most of the java concurrency interview questions are related to low-level threading, you will also find questions related to the Java concurrency API.
Java concurrency API and its application is an advanced Java topic. Your knowledge and proper responses to Java concurrency interview questions will provide you a definite edge over other candidates..
Below Java concurrency interview questions, answers, tips and samples will get you grounded on the fundamentals; helps you to memorize some important methods, and review the basic operations that you will frequently perform using Java collections API.
Important keywords are provided at the end of the questions. Review them, make them a part of your Java concurrency vocabulary, and talk about them confidently during your interview process.
What is Java Concurrency Framework?
Java Concurrency framework contains classes in the java.util.concurrent package that provide a high-level abstraction for creating and executing multi-threaded programs, instead of low-level multithreading via explicit thread creation and execution.
What are the key classes provided in the Java concurrency framework?
The key classes provided in the Java Concurrency framework are Executor, ExecutorSevice, Callable, and Future.
What are executors in Java programming language?
Executor is a class provided in the Java Concurrency Framework that is used to submit a task for execution without controlling how or when the task is executed. Executor decouples the task that needs to be executed from the creation and starting of threads.
What is the purpose of ExecutorService class in Java Concurrency Framework?
ExecutorService which extends from Executor, adds additional functionality to an Executor. ExecutorService has the ability to execute Callables and return Futures.
What is the purpose of Executors class in Java Concurrency Framework?
Executors is a class provided in the Java concurrency framework that provides factory methods to get different kinds of executors.
What are the different kinds of Executors?
There are four kinds of Executors.
1. Cached Thread Pool Executors – A cached thread pool executor will create new threads when they are needed and will reuse existing threads in the pool that are free. Threads that are not used for 1 min are removed from the pool.
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What are callables and futures in Java programming language.?
Callable is a functional interface similar to Runnable but return a value. Callable are submitted to ...
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What is Parallel Fork-Join framework?
Parallel Fork-Join framework is used for highly parallelizable tasks. Parallel Fork-Join framework increases ...
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What is Parallel Fork-Join task?
A parallel fork-join task represents the problem to solve. When executed by a fork-join pool ...
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What is the difference between RecursiveTask and RecursiveAction?
RecursiveTask’s compute() method returns a value, whereas RecursiveAction’s compute() method returns void...
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What are atomic variables in Java programming language?
Atomic variables are thread-safe variable classes provided in Java Concurrency framework in the java.util.concurrent.atomic package. Atomic variables can be used for ...
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What are Scheduled executors in Java programming language.?
Scheduled executors enables tasks to be executed after a delay or at regular intervals...
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What are concurrent collections?
Concurrent collections are collection classes provided in the Java concurrency framework that are thread-safe, and in addition are ...
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What are copy-on-write collections?
Copy-on-write collections are thread-safe and lock-safe collections provided in the Java concurrency framework. These collections are implemented ...
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Java - Interview Questions
