Class SLQueue

java.lang.Object
  |
  +--SLQueue

All Implemented Interfaces:

Queue

class SLQueue

extends java.lang.Object

implements Queue

SLQueue is an implementation of Queue, a repository for Objects. Objects are inserted using enqueue and removed using dequeue. Objects are removed in the same order in which they are inserted. A singly-linked list is used to maintain the Queue.

Nested Class Summary

(package private) class

SLQueue.Cell A Cell stores one Object in the Queue and points to the next newer Object if any.

Field Summary

protected SLQueue.Cell	head the Cell containing the next Object to be removed
protected SLQueue.Cell	tail the Cell containing the most recent Object inserted

Constructor Summary

SLQueue()
Construct an empty SLQueue.

Method Summary

java.lang.Object	dequeue() Remove an Object from the queue.
void	enqueue(java.lang.Object item) Insert an Object in the queue.
boolean	isEmpty() Indicate whether or not the Queue is empty

Methods inherited from class java.lang.Object

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

Field Detail

head

protected SLQueue.Cell head

the Cell containing the next Object to be removed

tail

protected SLQueue.Cell tail

the Cell containing the most recent Object inserted

Constructor Detail

SLQueue

public SLQueue()

Construct an empty SLQueue.

Method Detail

enqueue

public void enqueue(java.lang.Object item)

Insert an Object in the queue.

Specified by:

enqueue in interface Queue

Parameters:

item - the Object to be inserted

dequeue

public java.lang.Object dequeue()
                         throws EmptyQueueException

Remove an Object from the queue.

Specified by:

dequeue in interface Queue

Returns:

the Object removed

Throws:

EmptyQueueException - if the Queue is empty

isEmpty

public boolean isEmpty()

Indicate whether or not the Queue is empty

Specified by:

isEmpty in interface Queue

Returns:

boolean indicating whether or not the Queue is empty