| 25 |
|
* as well. If these requirements cannot be met, consider instead |
| 26 |
|
* subclassing {@link AbstractCollection}. |
| 27 |
|
* |
| 28 |
+ |
* <p>This class is a member of the |
| 29 |
+ |
* <a href="{@docRoot}/../guide/collections/index.html"> |
| 30 |
+ |
* Java Collections Framework</a>. |
| 31 |
+ |
* |
| 32 |
|
* @since 1.5 |
| 33 |
|
* @author Doug Lea |
| 34 |
|
* @param <E> the type of elements held in this collection |
| 43 |
|
protected AbstractQueue() { |
| 44 |
|
} |
| 45 |
|
|
| 42 |
– |
|
| 46 |
|
/** |
| 47 |
< |
* Adds the specified element to this queue. This implementation |
| 48 |
< |
* returns <tt>true</tt> if <tt>offer</tt> succeeds, else |
| 49 |
< |
* throws an IllegalStateException. |
| 50 |
< |
* |
| 48 |
< |
* @param o the element |
| 49 |
< |
* @return <tt>true</tt> (as per the general contract of |
| 50 |
< |
* <tt>Collection.add</tt>). |
| 47 |
> |
* Inserts the specified element into this queue if it is possible to do so |
| 48 |
> |
* immediately without violating capacity restrictions, returning |
| 49 |
> |
* <tt>true</tt> upon success and throwing an <tt>IllegalStateException</tt> |
| 50 |
> |
* if no space is currently available. |
| 51 |
|
* |
| 52 |
< |
* @throws NullPointerException if the specified element is <tt>null</tt> |
| 53 |
< |
* @throws IllegalStateException if element cannot be added |
| 52 |
> |
* <p>This implementation returns <tt>true</tt> if <tt>offer</tt> succeeds, |
| 53 |
> |
* else throws an <tt>IllegalStateException</tt>. |
| 54 |
> |
* |
| 55 |
> |
* @param e the element to add |
| 56 |
> |
* @return <tt>true</tt> (as per the spec for {@link Collection#add}) |
| 57 |
> |
* @throws IllegalStateException if the element cannot be added at this |
| 58 |
> |
* time due to capacity restrictions |
| 59 |
> |
* @throws NullPointerException if the specified element is null and |
| 60 |
> |
* this queue not permit null elements |
| 61 |
> |
* @throws ClassCastException if the class of the specified element |
| 62 |
> |
* prevents it from being added to this queue |
| 63 |
> |
* @throws IllegalArgumentException if some property of this element |
| 64 |
> |
* prevents it from being added to this queue |
| 65 |
|
*/ |
| 66 |
< |
public boolean add(E o) { |
| 67 |
< |
if (offer(o)) |
| 66 |
> |
public boolean add(E e) { |
| 67 |
> |
if (offer(e)) |
| 68 |
|
return true; |
| 69 |
|
else |
| 70 |
|
throw new IllegalStateException("Queue full"); |
| 71 |
|
} |
| 72 |
|
|
| 73 |
|
/** |
| 74 |
< |
* Retrieves and removes the head of this queue. |
| 75 |
< |
* This implementation returns the result of <tt>poll</tt> |
| 74 |
> |
* Retrieves and removes the head of this queue. This method differs |
| 75 |
> |
* from {@link #poll} only in that it throws an exception if this queue |
| 76 |
> |
* is empty. |
| 77 |
> |
* |
| 78 |
> |
* <p>This implementation returns the result of <tt>poll</tt> |
| 79 |
|
* unless the queue is empty. |
| 80 |
|
* |
| 81 |
< |
* @return the head of this queue. |
| 82 |
< |
* @throws NoSuchElementException if this queue is empty. |
| 81 |
> |
* @return the head of this queue |
| 82 |
> |
* @throws NoSuchElementException if this queue is empty |
| 83 |
|
*/ |
| 84 |
|
public E remove() { |
| 85 |
|
E x = poll(); |
| 89 |
|
throw new NoSuchElementException(); |
| 90 |
|
} |
| 91 |
|
|
| 78 |
– |
|
| 92 |
|
/** |
| 93 |
< |
* Retrieves, but does not remove, the head of this queue. |
| 94 |
< |
* This implementation returns the result of <tt>peek</tt> |
| 93 |
> |
* Retrieves, but does not remove, the head of this queue. This method |
| 94 |
> |
* differs from {@link #peek} only in that it throws an exception if |
| 95 |
> |
* this queue is empty. |
| 96 |
> |
* |
| 97 |
> |
* <p>This implementation returns the result of <tt>peek</tt> |
| 98 |
|
* unless the queue is empty. |
| 99 |
|
* |
| 100 |
< |
* @return the head of this queue. |
| 101 |
< |
* @throws NoSuchElementException if this queue is empty. |
| 100 |
> |
* @return the head of this queue |
| 101 |
> |
* @throws NoSuchElementException if this queue is empty |
| 102 |
|
*/ |
| 103 |
|
public E element() { |
| 104 |
|
E x = peek(); |
| 109 |
|
} |
| 110 |
|
|
| 111 |
|
/** |
| 112 |
< |
* Removes all of the elements from this collection. |
| 113 |
< |
* The collection will be empty after this call returns. |
| 112 |
> |
* Removes all of the elements from this queue. |
| 113 |
> |
* The queue will be empty after this call returns. |
| 114 |
> |
* |
| 115 |
|
* <p>This implementation repeatedly invokes {@link #poll poll} until it |
| 116 |
|
* returns <tt>null</tt>. |
| 117 |
|
*/ |
| 129 |
|
* |
| 130 |
|
* <p>This implementation iterates over the specified collection, |
| 131 |
|
* and adds each element returned by the iterator to this |
| 132 |
< |
* collection, in turn. A runtime exception encountered while |
| 132 |
> |
* queue, in turn. A runtime exception encountered while |
| 133 |
|
* trying to add an element (including, in particular, a |
| 134 |
|
* <tt>null</tt> element) may result in only some of the elements |
| 135 |
|
* having been successfully added when the associated exception is |
| 136 |
|
* thrown. |
| 137 |
|
* |
| 138 |
< |
* @param c collection whose elements are to be added to this collection. |
| 139 |
< |
* @return <tt>true</tt> if this collection changed as a result of the |
| 140 |
< |
* call. |
| 141 |
< |
* @throws NullPointerException if the specified collection or |
| 142 |
< |
* any of its elements are null. |
| 143 |
< |
* @throws IllegalArgumentException if c is this queue. |
| 144 |
< |
* |
| 138 |
> |
* @param c collection whose elements are to be added to this queue |
| 139 |
> |
* @return <tt>true</tt> if this queue changed as a result of the call |
| 140 |
> |
* @throws NullPointerException if the specified collection contains a |
| 141 |
> |
* null element and this queue does not permit null elements, |
| 142 |
> |
* or if the specified collection is null |
| 143 |
> |
* @throws ClassCastException if the class of an element of the specified |
| 144 |
> |
* collection prevents it from being added to this queue |
| 145 |
> |
* @throws IllegalArgumentException if some property of an element of the |
| 146 |
> |
* specified collection prevents it from being added to this |
| 147 |
> |
* queue, or if the specified collection is this queue |
| 148 |
> |
* @throws IllegalStateException if not all the elements can be added at |
| 149 |
> |
* this time due to insertion restrictions |
| 150 |
|
* @see #add(Object) |
| 151 |
|
*/ |
| 152 |
|
public boolean addAll(Collection<? extends E> c) { |
