org.jlf.log
Class QueueProcessor

java.lang.Object
  |
  +--org.jlf.log.QueueProcessor

All Implemented Interfaces:

java.lang.Runnable

Direct Known Subclasses:

SMTPQueueProcessor

public abstract class QueueProcessor

extends java.lang.Object

implements java.lang.Runnable

The QueueProcessor class is an abstract class designed to offload the processing of a set of items to another thread. Any number of producers from any number of threads can enqueue items to the queue processor. Upon enqueuing the first item, the queue processor will start a thread to process any items added to the queue. To use all of this capability, all you need do is subclass this class and implement the abstract processItem() method.

Field Summary

protected static long	NEVER_TIME_OUT_WAIT Constant to set the processor so it never times out while waiting for a request.
protected java.util.Vector	processorQueue This is a queue for the processor thread to use when processing the items.
protected java.lang.Thread	processorThread Holds the thread processing items queued.
protected java.util.Vector	producerQueue This is a queue for producer threads to add items that need processing.
protected long	timeOutInMilliseconds Timeout where the processor should wake up every so often to process events.

Constructor Summary

QueueProcessor()
Default constructor, starts the thread processing queue items.

Method Summary

void	enqueue(java.lang.Object itemToBeProcessed) Adds an item to be processed, returning as quickly as possible so the calling thread doesn't have to wait for the item to be processed.
protected abstract void	processItem(java.lang.Object queueItem) Override this method to process any items your producers have queued.
protected void	processQueueItems() Iterates through the collection of processorQueue items to process them.
void	run() Main method to process the queue.

Methods inherited from class java.lang.Object

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

Field Detail

NEVER_TIME_OUT_WAIT

protected static final long NEVER_TIME_OUT_WAIT

Constant to set the processor so it never times out while waiting for a request.

See Also:

Constant Field Values

timeOutInMilliseconds

protected long timeOutInMilliseconds

Timeout where the processor should wake up every so often to process events. The default, -1, makes it so the processor only wakes up when new items are added to the queue.

producerQueue

protected java.util.Vector producerQueue

This is a queue for producer threads to add items that need processing.

processorQueue

protected java.util.Vector processorQueue

This is a queue for the processor thread to use when processing the items. It is different from the producerQueue so that we can immediately free the lock on the producerQueue so producers aren't locked up while we process any items.

processorThread

protected java.lang.Thread processorThread

Holds the thread processing items queued.

Constructor Detail

QueueProcessor

public QueueProcessor()

Default constructor, starts the thread processing queue items. This constructor MUST be called or the processor thread won't start!

Method Detail

enqueue

public void enqueue(java.lang.Object itemToBeProcessed)

Adds an item to be processed, returning as quickly as possible so the calling thread doesn't have to wait for the item to be processed.

run

public void run()

Main method to process the queue. This method should NOT be overridden, implement the processItem() method instead!

Specified by:

run in interface java.lang.Runnable

processQueueItems

protected void processQueueItems()

Iterates through the collection of processorQueue items to process them.

processItem

protected abstract void processItem(java.lang.Object queueItem)

Override this method to process any items your producers have queued.