TransferQueue and LinkedTransferQueue Java Example
December 30, 2013
transfer(E e) method in TransferQueue
Suppose a producer reaches to TransferQueue to transfer an element and there is consumers waiting to take element, then producer directly transfers the element to consumer. If there is no consumer waiting, then producer will not directly put the element and returned, but it will wait for any consumer to consume the element.LinkedTransferQueue Java Example
java.util.concurrent.LinkedTransferQueue has been introduced in JDK 7 and is the part of java collection framework. LinkedTransferQueue is unbounded TransferQueue. It means LinkedTransferQueue has no size restriction. This queue follows first-in-first-out (FIFO) concept to get and add element. We will discuss some methods of LinkedTransferQueue.transfer(E e) : Inherited from TransferQueue in which producer transfers the element to consumer and waits if necessary.
put(E e) : producers put the element and it does not throw exception because there is no size restriction. LinkedTransferQueue is unbounded.
take() : It retrieves the element from queue and wait if empty.
Now find the example of LinkedTransferQueue.
LinkedTransferQueueDemo.java
package com.concretepage.util.concurrent;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.LinkedTransferQueue;
public class LinkedTransferQueueDemo {
static LinkedTransferQueue<String> lnkTransQueue = new LinkedTransferQueue<String>();
public static void main(String[] args) {
ExecutorService exService = Executors.newFixedThreadPool(2);
Producer producer = new LinkedTransferQueueDemo().new Producer();
Consumer consumer = new LinkedTransferQueueDemo().new Consumer();
exService.execute(producer);
exService.execute(consumer);
exService.shutdown();
}
class Producer implements Runnable{
@Override
public void run() {
for(int i=0;i<3;i++){
try {
System.out.println("Producer is waiting to transfer...");
lnkTransQueue.transfer("A"+i);
System.out.println("producer transfered element: A"+i);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
class Consumer implements Runnable{
@Override
public void run() {
for(int i=0;i<3;i++){
try {
System.out.println("Consumer is waiting to take element...");
String s= lnkTransQueue.take();
System.out.println("Consumer received Element: "+s);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}
Producer is waiting to transfer... Consumer is waiting to take element... Consumer received Element: A0 Consumer is waiting to take element... producer transfered element: A0 Producer is waiting to transfer... producer transfered element: A1 Producer is waiting to transfer... Consumer received Element: A1 Consumer is waiting to take element... Consumer received Element: A2 producer transfered element: A2
