| 8 |
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|
| 9 |
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/** |
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* A collection designed for holding elements prior to processing. |
| 11 |
< |
* Besides basic {@link java.util.Collection Collection} operations, queues provide |
| 12 |
< |
* additional insertion, extraction, and inspection operations. The names |
| 13 |
< |
* of the operations vary with their policies: |
| 11 |
> |
* Besides basic {@link java.util.Collection Collection} operations, |
| 12 |
> |
* queues provide additional insertion, extraction, and inspection |
| 13 |
> |
* operations. Each of these methods exists in two forms: one throws |
| 14 |
> |
* an exception if the operation fails, the other returns a special |
| 15 |
> |
* value (either <tt>null</tt> or <tt>false</tt>, depending on the |
| 16 |
> |
* operation). The latter form of the insert operation is designed |
| 17 |
> |
* specifically for use with capacity-restricted <tt>Queue</tt> |
| 18 |
> |
* implementations; in most implementations, insert operations cannot |
| 19 |
> |
* fail. |
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* |
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< |
*<table BORDER CELLPADDING=3 CELLSPACING=1> |
| 21 |
> |
* <table BORDER CELLPADDING=3 CELLSPACING=1> |
| 22 |
|
* <tr> |
| 23 |
< |
* <td><em>Operation</em></td> |
| 24 |
< |
* <td ALIGN=CENTER><em>Attempt</em></td> |
| 25 |
< |
* <td ALIGN=CENTER><em>Throw</em></td> |
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> |
* <td></td> |
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> |
* <td ALIGN=CENTER><em>Throws exception</em></td> |
| 25 |
> |
* <td ALIGN=CENTER><em>Returns special value</em></td> |
| 26 |
|
* </tr> |
| 27 |
|
* <tr> |
| 28 |
< |
* <td><em>insert</em></td> |
| 29 |
< |
* <td>offer(x)</td> |
| 30 |
< |
* <td>add(x)</td> |
| 28 |
> |
* <td><b>Insert</b></td> |
| 29 |
> |
* <td>{@link #add add(e)}</td> |
| 30 |
> |
* <td>{@link #offer offer(e)}</td> |
| 31 |
|
* </tr> |
| 32 |
|
* <tr> |
| 33 |
< |
* <td><em>extract</em></td> |
| 34 |
< |
* <td>poll()</td> |
| 35 |
< |
* <td>remove()</td> |
| 33 |
> |
* <td><b>Remove</b></td> |
| 34 |
> |
* <td>{@link #remove remove()}</td> |
| 35 |
> |
* <td>{@link #poll poll()}</td> |
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|
* </tr> |
| 37 |
|
* <tr> |
| 38 |
< |
* <td><em>inspect</em></td> |
| 39 |
< |
* <td>peek()</td> |
| 40 |
< |
* <td>element()</td> |
| 38 |
> |
* <td><b>Examine</b></td> |
| 39 |
> |
* <td>{@link #element element()}</td> |
| 40 |
> |
* <td>{@link #peek peek()}</td> |
| 41 |
|
* </tr> |
| 42 |
< |
*</table> |
| 42 |
> |
* </table> |
| 43 |
|
* |
| 44 |
|
* <p>Queues typically, but do not necessarily, order elements in a |
| 45 |
|
* FIFO (first-in-first-out) manner. Among the exceptions are |
