In this blog post we will talk and learn about one of the very important multi Threading Java interview question and question is that What is BlockingQueue? How can we implement Producer and Consumer problem using BlockingQueue?
- java.util.concurrent.BlockingQueue is a Queue that supports typically operations that wait for the queue to become non-empty when retrieving and removing an element and wait for space to become available in the queue while adding an element.
- BlockingQueue doesn’t allow to add null values and throw NullPointerException if you try to add null value in the queue.
- BlockingQueue implementations are thread-safe. All queuing methods are basically atomic in nature and use internal locks or other forms of concurrency control.
- BlockingQueue primarily used for implementing producer consumer problem.
Let’s try to understand using an example..
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package com.kkjavatutorials.client; import java.util.Random; import java.util.concurrent.ArrayBlockingQueue; import java.util.concurrent.BlockingQueue; public class ProduserAndConsumerImpUsingBlockingQueueTest { //Shared Queue private static BlockingQueue<Integer> queue = new ArrayBlockingQueue<>(10); public static void main(String[] args) throws InterruptedException { //Producer Thread Thread producerThread = new Thread(new Runnable() { @Override public void run() { try { producer(); } catch (InterruptedException e) { e.printStackTrace(); } } }); //Consumer Thread Thread consumerThread= new Thread(new Runnable() { @Override public void run() { try { Thread.sleep(100); } catch (InterruptedException e) { e.printStackTrace(); } try { consumer(); } catch (InterruptedException e) { e.printStackTrace(); } } }); producerThread.start(); consumerThread.start(); } private static void producer() throws InterruptedException{ Random random= new Random(); while (true) { Thread.sleep(2000); int produced = random.nextInt(100); queue.put(produced); System.out.println("Produced:"+produced); } } private static void consumer() throws InterruptedException{ while (true) { Thread.sleep(2000); Integer consumed = queue.take(); System.out.println("Consumed:"+consumed); } } } |
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That’s all about What is BlockingQueue? How can we implement Producer and Consumer problem using Blocking Queue?
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