org.jboss.util.collection

Class AbstractQueue<E>

java.lang.Object

java.util.AbstractCollection<E>

org.jboss.util.collection.AbstractQueue<E>

Type Parameters:

E - the element type

All Implemented Interfaces:

Iterable<E>, Collection<E>, Queue<E>

Direct Known Subclasses:

ListQueue

public abstract class AbstractQueue<E>
extends AbstractCollection<E>
implements Queue<E>

An abstract implementation of a Queue. Sub-classes must provide methods for addLast(Object) and removeFirst().

Version:

$Revision$

Author:

Jason Dillon

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_MAXIMUM_SIZE Default maximum queue size
protected int	maximumSize Maximum queue size

Fields inherited from interface org.jboss.util.collection.Queue

UNLIMITED_MAXIMUM_SIZE

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractQueue() Initializes the AbstractQueue.
protected	AbstractQueue(int maxSize) Initializes the AbstractQueue.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	add(E obj) Append and object to the underling list.
protected abstract boolean	addLast(E obj) Appends the given element to the end of the queue
void	clear() Removes all of the elements from this queue
int	getMaximumSize() Get the maximum size of the queue.
boolean	isEmpty() Check if the queue is empty.
boolean	isFull() Check if the queue is full.
E	remove() Remove and return the first object in the queue.
protected abstract E	removeFirst() Remove the first object in the queue
void	setMaximumSize(int size) Set the maximum size of the queue

Methods inherited from class java.util.AbstractCollection

addAll, contains, containsAll, iterator, remove, removeAll, retainAll, size, toArray, toArray, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.jboss.util.collection.Queue

getBack, getFront

Methods inherited from interface java.util.Collection

addAll, contains, containsAll, equals, hashCode, iterator, remove, removeAll, retainAll, size, toArray, toArray

Field Detail

DEFAULT_MAXIMUM_SIZE

public static int DEFAULT_MAXIMUM_SIZE

Default maximum queue size

maximumSize

protected int maximumSize

Maximum queue size

Constructor Detail

AbstractQueue

protected AbstractQueue()

Initializes the AbstractQueue.

AbstractQueue

protected AbstractQueue(int maxSize)

Initializes the AbstractQueue.

Parameters:

maxSize - Maximum queue size.

Throws:

IllegalArgumentException - Illegal size.

Method Detail

getMaximumSize

public int getMaximumSize()

Get the maximum size of the queue.

Specified by:

getMaximumSize in interface Queue<E>

Returns:

Maximum queue size or Queue.UNLIMITED_MAXIMUM_SIZE.

setMaximumSize

public void setMaximumSize(int size)

Set the maximum size of the queue

Specified by:

setMaximumSize in interface Queue<E>

Parameters:

size - New maximim queue size or Queue.UNLIMITED_MAXIMUM_SIZE.

Throws:

IllegalArgumentException - Illegal size.

isFull

public boolean isFull()

Check if the queue is full.

Specified by:

isFull in interface Queue<E>

Returns:

True if the queue is full.

isEmpty

public boolean isEmpty()

Check if the queue is empty.

Specified by:

isEmpty in interface Collection<E>

Specified by:

isEmpty in interface Queue<E>

Overrides:

isEmpty in class AbstractCollection<E>

Returns:

True if the queue is empty.

add

public boolean add(E obj)
            throws FullCollectionException

Append and object to the underling list.

Specified by:

add in interface Collection<E>

Specified by:

add in interface Queue<E>

Overrides:

add in class AbstractCollection<E>

Parameters:

obj - Object to enqueue.

Returns:

True if collection was modified.

Throws:

FullCollectionException - The queue is full.

remove

public E remove()
         throws EmptyCollectionException

Remove and return the first object in the queue.

Specified by:

remove in interface Queue<E>

Returns:

Dequeued object.

Throws:

EmptyCollectionException - The queue is empty.

clear

public void clear()

Removes all of the elements from this queue

Specified by:

clear in interface Collection<E>

Overrides:

clear in class AbstractCollection<E>

addLast

protected abstract boolean addLast(E obj)

Appends the given element to the end of the queue

Parameters:

obj - Object to append

Returns:

Per Collection.add(), we return a boolean to indicate if the object modified the collection.

removeFirst

protected abstract E removeFirst()

Remove the first object in the queue

Returns:

First object in the queue