Blockingqueue Inwards Coffee – Arrayblockingqueue Vs Linkedblockingqueue Illustration Programme Tutorial

BlockingQueue inward Java is added inward Java 1.5 along alongside diverse other concurrent Utility classes similar ConcurrentHashMap, Counting Semaphore, CopyOnWriteArrrayList etc. BlockingQueue is a unique collection type which non alone shop elements only too supports time period command past times introducing blocking if either BlockingQueue is total or empty. take() method of BlockingQueue volition block if Queue is empty as well as put() method of BlockingQueue volition block if Queue is full. This belongings makes BlockingQueue an ideal selection for implementing Producer consumer pattern pattern where 1 thread insert chemical gene into BlockingQueue as well as other thread consumes it. In this Java tutorial nosotros volition larn almost What is BlockingQueue inward Java, How to purpose BlockingQueue, ArrayBlockingQueue as well as LinkedBlockingQueue as well as unopen to of import properties of it.

Important properties of BlockingQueue inward Java

Before using whatever novel Collection cast e.g. BlockingQueue, I ever read at that topographic point API documentation to know to a greater extent than almost it. There are ever unopen to of import points which is worth remembering as well as avoids potential programming errors spell using novel Collection class. Following listing of points almost BlockingQueue inward Java volition tending to larn as well as empathize to a greater extent than almost it.

1) BlockingQueue inward Java doesn't allow aught elements, diverse implementation of BlockingQueue similar ArrayBlockingQueue, LinkedBlockingQueue throws NullPointerException when y'all endeavor to add together aught on queue.

BlockingQueue<String> bQueue = new ArrayBlockingQueue<String>(10);
//bQueue.put(null); //NullPointerException - BlockingQueue inward Java doesn't allow null
     
bQueue = new LinkedBlockingQueue<String>();
bQueue.put(null);

Exception inward thread "main" java.lang.NullPointerException
        at java.util.concurrent.LinkedBlockingQueue.put(LinkedBlockingQueue.java:288)

2) BlockingQueue tin last bounded or unbounded. Influenza A virus subtype H5N1 bounded BlockingQueue is 1 which is initialized alongside initial capacity as well as telephone telephone to put() volition last blocked if BlockingQueue is total as well as size is equal to capacity. This bounding nature makes it ideal to purpose a shared queue betwixt multiple threads similar inward most mutual Producer consumer solutions inward Java. An unbounded Queue is 1 which is initialized without capacity, genuinely past times default it initialized alongside Integer.MAX_VALUE. most mutual instance of BlockingQueue uses bounded BlockingQueue equally shown inward below example.

BlockingQueue<String> bQueue = new ArrayBlockingQueue<String>(2);
bQueue.put("Java");
System.out.println("Item 1 inserted into BlockingQueue");
bQueue.put("JDK");
System.out.println("Item 2 is inserted on BlockingQueue");
bQueue.put("J2SE");
System.out.println("Done");

Output:
Item 1 inserted into BlockingQueue
Item 2 is inserted on BlockingQueue

This code volition alone insert Java as well as JDK into BlockingQueue as well as thence it volition block spell inserting third chemical gene J2SE because size of BlockingQueue is 2 here.

3)BlockingQueue implementations similar ArrayBlockingQueue, LinkedBlockingQueue as well as PriorityBlockingQueue are thread-safe. All queuing method uses concurrency command as well as internal locks to perform functioning atomically. Since BlockingQueue too extend Collection, mass Collection operations similar addAll(), containsAll() are non performed atomically until whatever BlockingQueue implementation specifically supports it. So telephone telephone to addAll() may neglect after inserting distich of elements.

4) Common methods of BlockingQueue is are put() as well as take() which are blocking methods inward Java as well as used to insert as well as retrive elements from BlockingQueue inward Java. put() volition block if BlockingQueue is total as well as take() volition block if BlockingQueue is empty, telephone telephone to take() removes chemical gene from caput of Queue equally shown inward next example:

BlockingQueue<String> bQueue = new ArrayBlockingQueue<String>(2);
bQueue.put("Java"); //insert object into BlockingQueue
System.out.println("BlockingQueue after put: " + bQueue);
bQueue.take(); //retrieve object from BlockingQueue inward Java
System.out.println("BlockingQueue after take: " + bQueue);

Output:
BlockingQueue after put: [Java]
BlockingQueue after take: []

5) BlockingQueue interface extends Collection, Queue as well as Iterable interface which provides it all Collection as well as Queue related methods similar poll(), as well as peak(), dissimilar take(), peek() method returns caput of the queue without removing it, poll() too retrieves as well as removes elements from caput only tin facial expression till specified fourth dimension if Queue is empty.

BlockingQueue<String> linkedBQueue = new LinkedBlockingQueue<String>(2);
linkedBQueue.put("Java"); //puts object into BlockingQueue
System.out.println("size of BlockingQueue earlier peek : " + linkedBQueue.size());      
System.out.println("example of peek() inward BlockingQueue: " + linkedBQueue.peek());
System.out.println("size of BlockingQueue after peek : " + linkedBQueue.size());
System.out.println("calling poll() on BlockingQueue: " + linkedBQueue.poll());
System.out.println("size of BlockingQueue after poll : " + linkedBQueue.size());

Output:
size of BlockingQueue earlier peek : 1
instance of peek() inward BlockingQueue: Java
size of BlockingQueue after peek : 1
calling poll() on BlockingQueue: Java
size of BlockingQueue after poll : 0

6)Other of import methods from BlockingQueue inward Java is remainingCapacity() as well as offer(), old returns let on remaining infinite inward BlockingQueue, which tin last filled without blocking spell afterward insert object into queue if possible as well as render truthful if success as well as faux if neglect dissimilar add() method which throws IllegalStateException if it fails to insert object into BlockingQueue. Use offer() over add() wherever possible.

Usage of BlockingQueue inward Java

There tin last many creative usage of BlockingQueue inward Java given its time period command ability. Two of the most mutual ways I encounter programmer uses BlockingQueue is to implement Producer Consumer pattern pattern as well as implementing Bounded buffer inward Java. It surprisingly made coding as well as inter thread communication over a shared object really easy.

ArrayBlockingQueue as well as LinkedBlockingQueue inward Java

ArrayBlockingQueue as well as LinkedBlockingQueue are mutual implementation of BlockingQueue<E> interface. ArrayBlockingQueue is backed past times array  and Queue impose orders equally FIFO. caput of the queue is the oldest chemical gene inward damage of fourth dimension as well as tail of the queue is youngest element. ArrayBlockingQueue is too fixed size bounded buffer on the other paw LinkedBlockingQueue is an optionally bounded queue built on overstep of Linked nodes. In damage of throughput LinkedBlockingQueue provides higher throughput than ArrayBlockingQueue inward Java.

That’s all on What is BlockingQueue inward Java as well as How to purpose it. We receive got seen ii convenient implementation of BlockingQueue i.e. ArrayBlockingQueue as well as LinkedBlockingQueue which comes along alongside Java API. If y'all are implementing Producer Consumer pattern pattern inward Java, consider using BlockingQueue, it non alone brand coding tardily only too performs ameliorate as well as render ameliorate robustness as well as stability than writing your ain BlockingQueue or using naked wait as well as notify method.

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