org.exolab.jms.common.util
Class OrderedQueue

java.lang.Object
  |
  +--org.exolab.jms.common.util.OrderedQueue

public class OrderedQueue

extends java.lang.Object

The OrderedQueue is responsible for managing the expiration of the leases. The LeaseComparator is used to determine where they are inserted and the lease with the shortest duration is removed from the queue first. It is implemented suing a Vector but this could be changed to improve performance.

Version:

$Revision: 1.1 $ $Date: 2004/11/26 01:50:35 $

Author:

Jim Alateras

Constructor Summary

OrderedQueue(java.util.Comparator comparator)
Construct an instance of this class with the comparator to order the elements in the queue.

Method Summary

void	add(java.lang.Object object) Add this element to the queue in the required order.
void	clear() Remove all the elements from the queue
java.lang.Object	firstElement() Return the first element on the queue
boolean	remove(java.lang.Object object) Remove the object from the queue
java.lang.Object	removeFirstElement() Remove the first element from the queue or null if there are no elements on the queue.
int	size() Return the number elements in the queue

Methods inherited from class java.lang.Object

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

Constructor Detail

OrderedQueue

public OrderedQueue(java.util.Comparator comparator)

Construct an instance of this class with the comparator to order the elements in the queue. Elements with the same order value are placed after each other.

Parameters:

comparator - used for ordering

Method Detail

add

public void add(java.lang.Object object)

Add this element to the queue in the required order. It uses a binary search to locate the correct position

Parameters:

object - object to add

remove

public boolean remove(java.lang.Object object)

Remove the object from the queue

Parameters:

object - object to remove

Returns:

true if the object was removed

clear

public void clear()

Remove all the elements from the queue

size

public int size()

Return the number elements in the queue

Returns:

int size of the queue

firstElement

public java.lang.Object firstElement()

Return the first element on the queue

Returns:

Object

removeFirstElement

public java.lang.Object removeFirstElement()

Remove the first element from the queue or null if there are no elements on the queue.

Returns:

Object