org.lwes.listener
Class ThreadedDequeuer

java.lang.Object
  org.lwes.listener.ThreadedDequeuer

All Implemented Interfaces:

java.lang.Runnable

Direct Known Subclasses:

DatagramDequeuer

public abstract class ThreadedDequeuer
extends java.lang.Object
implements java.lang.Runnable

An abstract consumer of events.

Author:

Michael P. Lum

Field Summary

protected java.util.List<QueueElement>

queue

Constructor Summary

ThreadedDequeuer()
Default constructor.

Method Summary

void	addHandler(EventHandler handler) Add an event handler to this dequeuer.
void	addHandler(java.lang.String name, EventHandler handler) Adds a handler to this dequeuer with a specified name.
protected void	dispatchEvent(Event event) Handles events and calls EventHandler handlers.
EventHandler	getHandler(java.lang.String name) Get an event handler by name.
protected ThreadedEventDispatcher	getIdleProcessor() Gets an idle processor from the list
int	getMaxThreads() Gets the maximum number of threads allowed in the system
java.util.List<QueueElement>	getQueue() Returns the queue to use for this dequeuer
void	initialize() Default initialize() method.
void	makeAvailable(ThreadedEventDispatcher dispatcher) Makes a process available for dispatch
void	removeHandler(EventHandler handler) Removes a handler so it no longer is processing events
void	removeHandler(java.lang.String name) Removes a handler by name so it no longer is processing events
void	run() Default run loop.
void	setMaxThreads(int threads) Sets the maximum number of threads allowed in the system, up to 64.
void	setQueue(java.util.List<QueueElement> queue) Sets the queue to use for this dequeuer.
void	shutdown() Default shutdown() method.

Methods inherited from class java.lang.Object

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

Field Detail

queue

protected java.util.List<QueueElement> queue

Constructor Detail

ThreadedDequeuer

public ThreadedDequeuer()

Default constructor.

Method Detail

getQueue

public java.util.List<QueueElement> getQueue()

Returns the queue to use for this dequeuer

Returns:

the List queue

setQueue

public void setQueue(java.util.List<QueueElement> queue)

Sets the queue to use for this dequeuer. Warning: this List must be thread-synchronized!

Parameters:

queue - the thread-synchronized List element

getMaxThreads

public int getMaxThreads()

Gets the maximum number of threads allowed in the system

Returns:

the number of threads

setMaxThreads

public void setMaxThreads(int threads)

Sets the maximum number of threads allowed in the system, up to 64. The default is 20.

Parameters:

threads - the number of threads to allow.

getHandler

public EventHandler getHandler(java.lang.String name)

Get an event handler by name. Returns null if the handler does not exist.

Parameters:

name - the name of the event handler to fetch

Returns:

the EventHandler

addHandler

public void addHandler(EventHandler handler)

Add an event handler to this dequeuer. Events coming into the system will call all handlers via their callback.

Parameters:

handler - the actual handler

addHandler

public void addHandler(java.lang.String name,
                       EventHandler handler)

Adds a handler to this dequeuer with a specified name. Events coming into the system will call all handlers via their callback.

Parameters:

name - the name of this handler

handler - the actual handler

removeHandler

public void removeHandler(EventHandler handler)

Removes a handler so it no longer is processing events

Parameters:

handler - the handler to remove

removeHandler

public void removeHandler(java.lang.String name)

Removes a handler by name so it no longer is processing events

Parameters:

name - the name of the handler to remove

initialize

public void initialize()
                throws java.io.IOException

Default initialize() method. Should be overridden by classes extending ThreadedEnqueuer.

Throws:

java.io.IOException

shutdown

public void shutdown()

Default shutdown() method. Should be overridden by classes extending ThreadedDequeuer.

run

public void run()

Default run loop. Should be overridden by classes extending ThreadedDequeuer

Specified by:

run in interface java.lang.Runnable

dispatchEvent

protected void dispatchEvent(Event event)

Handles events and calls EventHandler handlers. Typically called from the dequeuer implementation to invoke the handler callbacks.

Parameters:

event - the Event to dispatch to the EventHandlers

getIdleProcessor

protected ThreadedEventDispatcher getIdleProcessor()

Gets an idle processor from the list

Returns:

a ThreadedEventDispatcher

makeAvailable

public void makeAvailable(ThreadedEventDispatcher dispatcher)

Makes a process available for dispatch

Parameters:

dispatcher - the dispatcher to make available