QueueInterface.java

package socialnetwork;

import Graph.EmptyQueueException;

/**
   An interface for the ADT queue.   
   @author Frank M. Carrano
   @author Timothy M. Henry
   @version 4.0
*/
public interface QueueInterface<T>
{
  /** Adds a new entry to the back of this queue.
      @param newEntry  An object to be added. */
  public void enqueue(T newEntry);
  
  /** Removes and returns the entry at the front of this queue.
      @return  The object at the front of the queue. 
      @throws  EmptyQueueException if the queue is empty before the operation. */
  public T dequeue();
  
  /**  Retrieves the entry at the front of this queue.
      @return  The object at the front of the queue.
      @throws  EmptyQueueException if the queue is empty. */
  public T getFront();
  
  /** Detects whether this queue is empty.
      @return  True if the queue is empty, or false otherwise. */
  public boolean isEmpty();
  
  /** Removes all entries from this queue. */
  public void clear();
} // end QueueInterface