54 |
|
* used as a special return value by the <tt>poll</tt> method to |
55 |
|
* indicate that the queue contains no elements. |
56 |
|
* |
57 |
+ |
* <p><tt>Queue</tt> implementations generally do not define |
58 |
+ |
* element-based versions of methods <tt>equals</tt> and |
59 |
+ |
* <tt>hashCode</tt> but instead inherit the identity based versions |
60 |
+ |
* from class <tt>Object</tt>, because element-based equality is not |
61 |
+ |
* always well-defined for queues with the same elements but different |
62 |
+ |
* ordering properties. |
63 |
+ |
* |
64 |
+ |
* |
65 |
|
* <p>This interface is a member of the |
66 |
|
* <a href="{@docRoot}/../guide/collections/index.html"> |
67 |
|
* Java Collections Framework</a>. |
69 |
|
* @see java.util.Collection |
70 |
|
* @see LinkedList |
71 |
|
* @see PriorityQueue |
72 |
< |
* @see java.util.concurrent.LinkedQueue |
72 |
> |
* @see java.util.concurrent.LinkedBlockingQueue |
73 |
|
* @see java.util.concurrent.BlockingQueue |
74 |
|
* @see java.util.concurrent.ArrayBlockingQueue |
75 |
|
* @see java.util.concurrent.LinkedBlockingQueue |