File	Doc	Category	Size	Date	Package
AbstractQueue.java	API Doc	Java SE 6 API	6353	Tue Jun 10 00:25:52 BST 2008	java.util

AbstractQueue

• java.lang.Object
  • java.util.AbstractCollection

Fields Summary

Constructors Summary
protected AbstractQueue() Constructor for use by subclasses.

Methods Summary
public boolean	add(E e) Inserts the specified element into this queue if it is possible to do so immediately without violating capacity restrictions, returning true upon success and throwing an IllegalStateException if no space is currently available. This implementation returns true if offer succeeds, else throws an IllegalStateException. param e the element to add return true (as specified by {@link Collection#add}) throws IllegalStateException if the element cannot be added at this time due to capacity restrictions throws ClassCastException if the class of the specified element prevents it from being added to this queue throws NullPointerException if the specified element is null and this queue does not permit null elements throws IllegalArgumentException if some property of this element prevents it from being added to this queue if (offer(e)) return true; else throw new IllegalStateException("Queue full");
public boolean	addAll(java.util.Collection c) Adds all of the elements in the specified collection to this queue. Attempts to addAll of a queue to itself result in IllegalArgumentException. Further, the behavior of this operation is undefined if the specified collection is modified while the operation is in progress. This implementation iterates over the specified collection, and adds each element returned by the iterator to this queue, in turn. A runtime exception encountered while trying to add an element (including, in particular, a null element) may result in only some of the elements having been successfully added when the associated exception is thrown. param c collection containing elements to be added to this queue return true if this queue changed as a result of the call throws ClassCastException if the class of an element of the specified collection prevents it from being added to this queue throws NullPointerException if the specified collection contains a null element and this queue does not permit null elements, or if the specified collection is null throws IllegalArgumentException if some property of an element of the specified collection prevents it from being added to this queue, or if the specified collection is this queue throws IllegalStateException if not all the elements can be added at this time due to insertion restrictions see #add(Object) if (c == null) throw new NullPointerException(); if (c == this) throw new IllegalArgumentException(); boolean modified = false; Iterator<? extends E> e = c.iterator(); while (e.hasNext()) { if (add(e.next())) modified = true; } return modified;
public void	clear() Removes all of the elements from this queue. The queue will be empty after this call returns. This implementation repeatedly invokes {@link #poll poll} until it returns null. while (poll() != null) ;
public E	element() Retrieves, but does not remove, the head of this queue. This method differs from {@link #peek peek} only in that it throws an exception if this queue is empty. This implementation returns the result of peek unless the queue is empty. return the head of this queue throws NoSuchElementException if this queue is empty E x = peek(); if (x != null) return x; else throw new NoSuchElementException();
public E	remove() Retrieves and removes the head of this queue. This method differs from {@link #poll poll} only in that it throws an exception if this queue is empty. This implementation returns the result of poll unless the queue is empty. return the head of this queue throws NoSuchElementException if this queue is empty E x = poll(); if (x != null) return x; else throw new NoSuchElementException();