simple.util
Class BlockingQueue<E>

java.lang.Object
  simple.util.BlockingQueue<E>

All Implemented Interfaces:

java.lang.Iterable<E>, java.util.Collection<E>, java.util.concurrent.BlockingQueue<E>, java.util.Queue<E>

public class BlockingQueue<E>
extends java.lang.Object
implements java.util.concurrent.BlockingQueue<E>

Blocks until the list has an item.
Created: Feb 8, 2010

Author:

Kenneth Pierce

Field Summary

private boolean	fixedSize
private java.util.Vector<E>	list

Constructor Summary

BlockingQueue(int size)
Creates a new fixed size First In First Out queue of size size.

BlockingQueue(int size, int increment)
Creates a new First In First Out queue with the initial size size.

Method Summary

boolean	add(E e) Attempts to add e to the stack, throwing an exception if the queue is full.
boolean	addAll(java.util.Collection<? extends E> c) Adds the collection to the queue if there is enough room.
void	clear()
boolean	contains(java.lang.Object e)
boolean	containsAll(java.util.Collection<?> c)
int	drainTo(java.util.Collection<? super E> c)
int	drainTo(java.util.Collection<? super E> c, int max)
E	element() Returns the first element added or throws an exception if the queue is empty.
boolean	isEmpty()
boolean	isFull() Whether the queue is full or not.
java.util.Iterator<E>	iterator()
boolean	offer(E e) Attempts to add e to the queue.
boolean	offer(E e, long timeout, java.util.concurrent.TimeUnit unit) Attempts to add e to the queue.
E	peek() Returns the first element added or null if the queue is empty.
E	poll() Removes and returns the first element added or null if the queue is empty.
E	poll(long timeout, java.util.concurrent.TimeUnit unit) Removes and returns the first element added.
void	put(E e) Adds the element to the list, blocking if the queue is full.
int	remainingCapacity() Returns the remaining capacity of the queue.
E	remove() Removes and returns the first element added.
boolean	remove(java.lang.Object e)
boolean	removeAll(java.util.Collection<?> c)
boolean	retainAll(java.util.Collection<?> c)
int	size()
E	take() Removes and returns the first element added, blocking if the queue is empty.
java.lang.Object[]	toArray()
<T> T[]	toArray(T[] a)

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Collection

equals, hashCode

Field Detail

list

private final java.util.Vector<E> list

fixedSize

private final boolean fixedSize

Constructor Detail

BlockingQueue

public BlockingQueue(int size)

Creates a new fixed size First In First Out queue of size size.

Parameters:

size - Capacity of the queue

BlockingQueue

public BlockingQueue(int size,
                     int increment)

Creates a new First In First Out queue with the initial size size.

Parameters:

size - Initial size of the queue

increment - Number of slots to add when full. If negative or zero the number of slots double.

Method Detail

add

public boolean add(E e)

Attempts to add e to the stack, throwing an exception if the queue is full.

Specified by:

add in interface java.util.Collection<E>

Specified by:

add in interface java.util.concurrent.BlockingQueue<E>

Specified by:

add in interface java.util.Queue<E>

Parameters:

e - The element to add.

Returns:

false if there was an underlying error.

Throws:

{@link - java.lang.IllegalStateException} if the stack is full.

{@link - java.lang.NullPointerException} if e is null.

See Also:

BlockingQueue.add(java.lang.Object), offer(Object)

offer

public boolean offer(E e)

Attempts to add e to the queue.

Specified by:

offer in interface java.util.concurrent.BlockingQueue<E>

Specified by:

offer in interface java.util.Queue<E>

Parameters:

e - Element to add.

Returns:

false if queue is full or there was an underlying error.

Throws:

{@link - java.lang.NullPointerException} if e is null

See Also:

BlockingQueue.offer(java.lang.Object), add(Object), offer(Object, long, TimeUnit)

offer

public boolean offer(E e,
                     long timeout,
                     java.util.concurrent.TimeUnit unit)
              throws java.lang.InterruptedException

Attempts to add e to the queue. Will wait the specified time if the queue is full.

Specified by:

offer in interface java.util.concurrent.BlockingQueue<E>

Parameters:

e - Element to add.

timeout - Length of time to wait.

unit - Units of time to wait.

Returns:

false if the waited time elapsed and the queue is still full or there was an underlying error.

Throws:

{@link - java.lang.InterruptedException} if interrupted

{@link - java.lang.NullPointerException} if e is null

java.lang.InterruptedException

See Also:

BlockingQueue.offer(java.lang.Object, long, java.util.concurrent.TimeUnit)

poll

public E poll(long timeout,
              java.util.concurrent.TimeUnit unit)
       throws java.lang.InterruptedException

Removes and returns the first element added. Will wait timeout unit if the queue is empty.

Specified by:

poll in interface java.util.concurrent.BlockingQueue<E>

Parameters:

timeout - Amount to wait

unit - Units to wait

Returns:

The first element added or null if timed out.

Throws:

{@link - java.lang.InterruptedException} if interrupted.

java.lang.InterruptedException

See Also:

BlockingQueue.poll(long, java.util.concurrent.TimeUnit)

put

public void put(E e)
         throws java.lang.InterruptedException

Adds the element to the list, blocking if the queue is full.

Specified by:

put in interface java.util.concurrent.BlockingQueue<E>

Throws:

{@link - java.lang.InterruptedException} if interrupted.

java.lang.InterruptedException

See Also:

BlockingQueue.put(java.lang.Object)

remove

public boolean remove(java.lang.Object e)

Specified by:

remove in interface java.util.Collection<E>

Specified by:

remove in interface java.util.concurrent.BlockingQueue<E>

take

public E take()
       throws java.lang.InterruptedException

Removes and returns the first element added, blocking if the queue is empty.

Specified by:

take in interface java.util.concurrent.BlockingQueue<E>

Returns:

The first element added.

Throws:

java.lang.InterruptedException

See Also:

BlockingQueue.take(), peek(), poll(), poll(long, TimeUnit)

element

public E element()

Returns the first element added or throws an exception if the queue is empty.

Specified by:

element in interface java.util.Queue<E>

Returns:

The first element added.

Throws:

{@link - java.util.NoSuchElementException} if the queue is empty.

See Also:

Queue.element(), peek(), take()

peek

public E peek()

Returns the first element added or null if the queue is empty.

Specified by:

peek in interface java.util.Queue<E>

Returns:

the first element added or null if the queue is empty.

See Also:

Queue.peek(), element(), take()

poll

public E poll()

Removes and returns the first element added or null if the queue is empty.

Specified by:

poll in interface java.util.Queue<E>

Returns:

The first element added or null if the queue is empty.

See Also:

Queue.poll(), remove(), poll(long, TimeUnit)

remove

public E remove()

Removes and returns the first element added. Throws an exception if the queue is empty.

Specified by:

remove in interface java.util.Queue<E>

Returns:

The first element added.

Throws:

{@link - java.util.NoSuchElementException} if empty.

See Also:

Queue.remove(), poll()

remainingCapacity

public int remainingCapacity()

Returns the remaining capacity of the queue.

Specified by:

remainingCapacity in interface java.util.concurrent.BlockingQueue<E>

Returns:

The remaining capacity of the queue or Integer.MAX_VALUE if the size is not fixed.

See Also:

BlockingQueue.remainingCapacity()

isFull

public boolean isFull()

Whether the queue is full or not.

Returns:

true if the queue is full. Always returns false if the queue is not a fixed size.

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface java.util.Collection<E>

size

public int size()

Specified by:

size in interface java.util.Collection<E>

clear

public void clear()

Specified by:

clear in interface java.util.Collection<E>

addAll

public boolean addAll(java.util.Collection<? extends E> c)

Adds the collection to the queue if there is enough room.

Specified by:

addAll in interface java.util.Collection<E>

Returns:

true if all were added, false otherwise.

See Also:

Collection.addAll(java.util.Collection)

containsAll

public boolean containsAll(java.util.Collection<?> c)

Specified by:

containsAll in interface java.util.Collection<E>

iterator

public java.util.Iterator<E> iterator()

Specified by:

iterator in interface java.lang.Iterable<E>

Specified by:

iterator in interface java.util.Collection<E>

removeAll

public boolean removeAll(java.util.Collection<?> c)

Specified by:

removeAll in interface java.util.Collection<E>

retainAll

public boolean retainAll(java.util.Collection<?> c)

Specified by:

retainAll in interface java.util.Collection<E>

toArray

public java.lang.Object[] toArray()

Specified by:

toArray in interface java.util.Collection<E>

toArray

public <T> T[] toArray(T[] a)

Specified by:

toArray in interface java.util.Collection<E>

contains

public boolean contains(java.lang.Object e)

Specified by:

contains in interface java.util.Collection<E>

Specified by:

contains in interface java.util.concurrent.BlockingQueue<E>

drainTo

public int drainTo(java.util.Collection<? super E> c)

Specified by:

drainTo in interface java.util.concurrent.BlockingQueue<E>

drainTo

public int drainTo(java.util.Collection<? super E> c,
                   int max)

Specified by:

drainTo in interface java.util.concurrent.BlockingQueue<E>