org.jmxtrans.embedded.util.concurrent

Class DiscardingBlockingQueue<E>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractQueue<E>

java.util.concurrent.ArrayBlockingQueue<E>

org.jmxtrans.embedded.util.concurrent.DiscardingBlockingQueue<E>

All Implemented Interfaces:

Serializable, Iterable<E>, Collection<E>, BlockingQueue<E>, Queue<E>, DiscardingBlockingQueueMBean

public class DiscardingBlockingQueue<E>
extends ArrayBlockingQueue<E>
implements DiscardingBlockingQueueMBean

Automatically discard the oldest element if the queue is full.

Author:

Cyrille Le Clerc

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
DiscardingBlockingQueue(int capacity) Creates a DiscardingBlockingQueue with the given (fixed) capacity and default access policy.
DiscardingBlockingQueue(int capacity, boolean fair) Creates a DiscardingBlockingQueue with the given (fixed) capacity and the specified access policy.
DiscardingBlockingQueue(int capacity, boolean fair, Collection<? extends E> c) Creates an DiscardingBlockingQueue with the given (fixed) capacity, the specified access policy and initially containing the elements of the given collection, added in traversal order of the collection's iterator.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	add(E e) Add the given element to the BlockingQueue removing elements if necessary (ie if the queue is full).
boolean	addAll(Collection<? extends E> c) Offer the given elements to the BlockingQueue removing elements if necessary (ie if the queue is full).
protected void	discardingOffer(E e) Offer the given element to the BlockingQueue removing elements if necessary (ie if the queue is full).
int	getDiscardedElementCount()
boolean	offer(E e) Offer the given element to the BlockingQueue removing elements if necessary (ie if the queue is full).
boolean	offer(E e, long timeout, TimeUnit unit) Offer the given element to the BlockingQueue removing elements if necessary (ie if the queue is full).
void	put(E e) Add the given element to the BlockingQueue removing elements if necessary (ie if the queue is full).

Methods inherited from class java.util.concurrent.ArrayBlockingQueue

clear, contains, drainTo, drainTo, iterator, peek, poll, poll, remainingCapacity, remove, size, take, toArray, toArray, toString

Methods inherited from class java.util.AbstractQueue

element, remove

Methods inherited from class java.util.AbstractCollection

containsAll, isEmpty, removeAll, retainAll

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Queue

element, remove

Methods inherited from interface java.util.Collection

containsAll, equals, hashCode, isEmpty, removeAll, retainAll

Constructor Detail

DiscardingBlockingQueue

public DiscardingBlockingQueue(int capacity)

Creates a DiscardingBlockingQueue with the given (fixed) capacity and default access policy.

Parameters:

capacity - the capacity of this queue

Throws:

IllegalArgumentException - if capacity < 1

DiscardingBlockingQueue

public DiscardingBlockingQueue(int capacity,
                       boolean fair)

Creates a DiscardingBlockingQueue with the given (fixed) capacity and the specified access policy.

Parameters:

capacity - the capacity of this queue

fair - if true then queue accesses for threads blocked on insertion or removal, are processed in FIFO order; if false the access order is unspecified.

Throws:

IllegalArgumentException - if capacity < 1

DiscardingBlockingQueue

public DiscardingBlockingQueue(int capacity,
                       boolean fair,
                       Collection<? extends E> c)

Creates an DiscardingBlockingQueue with the given (fixed) capacity, the specified access policy and initially containing the elements of the given collection, added in traversal order of the collection's iterator.

Parameters:

capacity - the capacity of this queue

fair - if true then queue accesses for threads blocked on insertion or removal, are processed in FIFO order; if false the access order is unspecified.

c - the collection of elements to initially contain

Throws:

IllegalArgumentException - if capacity is less than c.size(), or less than 1.

NullPointerException - if the specified collection or any

Method Detail

discardingOffer

protected void discardingOffer(E e)

Offer the given element to the BlockingQueue removing elements if necessary (ie if the queue is full).

Parameters:

e - the element to add to the queue

add

public boolean add(E e)

Add the given element to the BlockingQueue removing elements if necessary (ie if the queue is full).

Specified by:

add in interface Collection<E>

Specified by:

add in interface BlockingQueue<E>

Specified by:

add in interface Queue<E>

Overrides:

add in class ArrayBlockingQueue<E>

Parameters:

e - the element to add to the queue

Returns:

true

offer

public boolean offer(E e)

Offer the given element to the BlockingQueue removing elements if necessary (ie if the queue is full).

Specified by:

offer in interface BlockingQueue<E>

Specified by:

offer in interface Queue<E>

Overrides:

offer in class ArrayBlockingQueue<E>

Parameters:

e - the element to add to the queue

Returns:

true

put

public void put(E e)
         throws InterruptedException

Add the given element to the BlockingQueue removing elements if necessary (ie if the queue is full).

Specified by:

put in interface BlockingQueue<E>

Overrides:

put in class ArrayBlockingQueue<E>

Parameters:

e - the element to add to the queue

Throws:

InterruptedException

offer

public boolean offer(E e,
            long timeout,
            TimeUnit unit)
              throws InterruptedException

Offer the given element to the BlockingQueue removing elements if necessary (ie if the queue is full).

Specified by:

offer in interface BlockingQueue<E>

Overrides:

offer in class ArrayBlockingQueue<E>

Parameters:

e - the element to add to the queue

Returns:

true

Throws:

InterruptedException

addAll

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

Offer the given elements to the BlockingQueue removing elements if necessary (ie if the queue is full).

Specified by:

addAll in interface Collection<E>

Overrides:

addAll in class AbstractQueue<E>

Parameters:

c - the element to add to the queue

Returns:

true if the given elements collection is not empty

getDiscardedElementCount

public int getDiscardedElementCount()

Specified by:

getDiscardedElementCount in interface DiscardingBlockingQueueMBean