de.lmu.ifi.dbs.elki.utilities
Class Queue<O>

java.lang.Object
  de.lmu.ifi.dbs.elki.utilities.Queue<O>

public class Queue<O>
extends Object

Provides a simple queue with a linked list data structure.

Author:

Elke Achtert

Nested Class Summary

(package private) class

Queue.QueueElement An element in the queue: holds the underlying objcet and the next element in the queue.

Field Summary

private Queue.QueueElement	first The first of this queue, null if the queue is empty.
private Queue.QueueElement	last The last element of this queue.

Constructor Summary

Queue()

Method Summary

O	dequeue() Removes the first object from the queue and returns it.
void	enqueue(O object) Appends the specified object to the end of the queue.
O	firstObject() Returns the first object of the queue, but does not remove it.
boolean	isEmpty() Returns true, if this queue is empty, false otherwise.

Methods inherited from class java.lang.Object

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

Field Detail

first

private Queue.QueueElement first

The first of this queue, null if the queue is empty.

last

private Queue.QueueElement last

The last element of this queue.

Constructor Detail

Queue

public Queue()

Method Detail

enqueue

public void enqueue(O object)

Appends the specified object to the end of the queue.

Parameters:

object - the object to be enqueued

dequeue

public O dequeue()

Removes the first object from the queue and returns it.

Returns:

the first object of the queue

Throws:

NoSuchElementException - if the queue is empty

firstObject

public O firstObject()

Returns the first object of the queue, but does not remove it.

Returns:

the first object of the queue

isEmpty

public boolean isEmpty()

Returns true, if this queue is empty, false otherwise.

Returns:

true, if this queue is empty.