Package org.threadly.concurrent.processing

Class BlockingQueueConsumer<T>

java.lang.Object

org.threadly.util.AbstractService

org.threadly.concurrent.processing.BlockingQueueConsumer<T>

Type Parameters:

T - Type of items contained in the queue to be consumed

All Implemented Interfaces:

Service

public abstract class BlockingQueueConsumer<T>
extends AbstractService

This class is designed for handling the threading and consumption of a high throughput BlockingQueue. This class will create a thread to block on for the queue, and provide the result to the abstract accept(Object). For low throughput queues, or where you want threads shared, consider using instead Poller.consumeQueue(java.util.Queue, Consumer, ExceptionHandler).

This implementation will create a single thread, serially calling to accept(Object), and not attempting to consume the next item till after it returns. If any errors happen similar handleException(Throwable) will block consuming the next item from the queue.

By implementing Service this class handles the thread lifecycle. Item consumption will start when AbstractService.start() is invoked, and will continue until AbstractService.stop() is invoked. When stopped, the consumer thread will be interrupted. This is necessary to unblock from consuming from the queue, but may impact the accepting code if it is currently handling an item.

Since:

5.37 (Former version existed at org.threadly.concurrent)

Constructor Summary

Constructors

Constructor	Description
BlockingQueueConsumer(java.util.concurrent.ThreadFactory threadFactory, java.util.concurrent.BlockingQueue<? extends T> queue)	Constructs a new consumer, with a provided queue to consume from, and an acceptor to accept items.

Method Summary

Modifier and Type	Method	Description
static <T> BlockingQueueConsumer<T>	makeForHandlers(java.util.concurrent.ThreadFactory threadFactory, java.util.concurrent.BlockingQueue<? extends T> queue, java.util.function.Consumer<T> consumer, ExceptionHandler exceptionHandler)	Construct a new BlockingQueueConsumer in case an abstract implementation is not preferred.

Methods inherited from class org.threadly.util.AbstractService

hasStopped, isRunning, start, startIfNotStarted, stop, stopIfRunning

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BlockingQueueConsumer

public BlockingQueueConsumer(java.util.concurrent.ThreadFactory threadFactory,
                             java.util.concurrent.BlockingQueue<? extends T> queue)

Constructs a new consumer, with a provided queue to consume from, and an acceptor to accept items.

Parameters:

threadFactory - ThreadFactory to construct new thread for consumer to run on

queue - Queue to consume items from

Method Detail

makeForHandlers

public static <T> BlockingQueueConsumer<T> makeForHandlers(java.util.concurrent.ThreadFactory threadFactory,
                                                           java.util.concurrent.BlockingQueue<? extends T> queue,
                                                           java.util.function.Consumer<T> consumer,
                                                           ExceptionHandler exceptionHandler)

Construct a new BlockingQueueConsumer in case an abstract implementation is not preferred.

Type Parameters:

T - The type of object to consume from the queue

Parameters:

threadFactory - ThreadFactory to construct new thread for consumer to run on

queue - Queue to consume items from

consumer - Consumer to provide items from queue on

exceptionHandler - Handler to send errors to, if null ExceptionUtils.handleException(java.lang.Throwable) is used

Returns:

A new BlockingQueueConsumer ready to start()