simple.util
Class BlockingStack<E>

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

All Implemented Interfaces:

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

public class BlockingStack<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

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

BlockingStack(int size, int increment)
Creates a new First In Last 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 stack is full.
boolean	addAll(java.util.Collection<? extends E> c) Adds the collection to the stack 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 last element added or throws an exception if the stack is empty.
boolean	isEmpty()
boolean	isFull() Whether the stack is full or not.
java.util.Iterator<E>	iterator()
boolean	offer(E e) Attempts to add e to the stack.
boolean	offer(E e, long timeout, java.util.concurrent.TimeUnit unit) Attempts to add e to the stack.
E	peek() Returns the last element added or null if the stack is empty.
E	poll() Removes and returns the last element added or null if the stack is empty.
E	poll(long timeout, java.util.concurrent.TimeUnit unit) Removes and returns the last element added.
void	put(E e) Adds the element to the list, blocking if the stack is full.
int	remainingCapacity() Returns the remaining capacity of the stack.
E	remove() Removes and returns the last 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 last element added, blocking if the stack 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

BlockingStack

public BlockingStack(int size)

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

Parameters:

size - Size of the queue.

BlockingStack

public BlockingStack(int size,
                     int increment)

Creates a new First In Last 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 stack 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 stack.

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 stack 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 stack. Will wait the specified time if the stack 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 stack 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 last element added. Will wait timeout unit if the stack is empty.

Specified by:

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

Parameters:

timeout - Amount to wait

unit - Units to wait

Returns:

The last 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 stack 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 last element added, blocking if the stack is empty.

Specified by:

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

Returns:

The last element added.

Throws:

java.lang.InterruptedException

See Also:

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

element

public E element()

Returns the last element added or throws an exception if the stack is empty.

Specified by:

element in interface java.util.Queue<E>

Returns:

The last element added.

Throws:

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

See Also:

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

peek

public E peek()

Returns the last element added or null if the stack is empty.

Specified by:

peek in interface java.util.Queue<E>

Returns:

the last element added or null if the stack is empty.

See Also:

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

poll

public E poll()

Removes and returns the last element added or null if the stack is empty.

Specified by:

poll in interface java.util.Queue<E>

Returns:

The last element added or null if the stack is empty.

See Also:

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

remove

public E remove()

Removes and returns the last element added. Throws an exception if the list is empty.

Specified by:

remove in interface java.util.Queue<E>

Returns:

The last element added.

Throws:

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

See Also:

Queue.remove(), poll()

remainingCapacity

public int remainingCapacity()

Returns the remaining capacity of the stack.

Specified by:

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

Returns:

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

See Also:

BlockingQueue.remainingCapacity()

isFull

public boolean isFull()

Whether the stack is full or not.

Returns:

true if the stack is full. Always returns false if the stack 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 stack 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>