| 1 |
|
/* |
| 2 |
|
* %W% %E% |
| 3 |
|
* |
| 4 |
< |
* Copyright 2005 Sun Microsystems, Inc. All rights reserved. |
| 4 |
> |
* Copyright 2006 Sun Microsystems, Inc. All rights reserved. |
| 5 |
|
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. |
| 6 |
|
*/ |
| 7 |
|
|
| 8 |
|
package java.util; |
| 9 |
– |
import java.util.*; // for javadoc (till 6280605 is fixed) |
| 9 |
|
import java.util.Map.Entry; |
| 10 |
|
|
| 11 |
|
/** |
| 29 |
|
* constructor, as per the recommendation in the <tt>Map</tt> interface |
| 30 |
|
* specification. |
| 31 |
|
* |
| 32 |
< |
* <p>The documentation for each non-abstract methods in this class describes its |
| 32 |
> |
* <p>The documentation for each non-abstract method in this class describes its |
| 33 |
|
* implementation in detail. Each of these methods may be overridden if the |
| 34 |
|
* map being implemented admits a more efficient implementation. |
| 35 |
|
* |
| 36 |
|
* <p>This class is a member of the |
| 37 |
< |
* <a href="{@docRoot}/../guide/collections/index.html"> |
| 37 |
> |
* <a href="{@docRoot}/../technotes/guides/collections/index.html"> |
| 38 |
|
* Java Collections Framework</a>. |
| 39 |
|
* |
| 40 |
|
* @param <K> the type of keys maintained by this map |
| 595 |
|
return oldValue; |
| 596 |
|
} |
| 597 |
|
|
| 598 |
+ |
/** |
| 599 |
+ |
* Compares the specified object with this entry for equality. |
| 600 |
+ |
* Returns {@code true} if the given object is also a map entry and |
| 601 |
+ |
* the two entries represent the same mapping. More formally, two |
| 602 |
+ |
* entries {@code e1} and {@code e2} represent the same mapping |
| 603 |
+ |
* if<pre> |
| 604 |
+ |
* (e1.getKey()==null ? |
| 605 |
+ |
* e2.getKey()==null : |
| 606 |
+ |
* e1.getKey().equals(e2.getKey())) |
| 607 |
+ |
* && |
| 608 |
+ |
* (e1.getValue()==null ? |
| 609 |
+ |
* e2.getValue()==null : |
| 610 |
+ |
* e1.getValue().equals(e2.getValue()))</pre> |
| 611 |
+ |
* This ensures that the {@code equals} method works properly across |
| 612 |
+ |
* different implementations of the {@code Map.Entry} interface. |
| 613 |
+ |
* |
| 614 |
+ |
* @param o object to be compared for equality with this map entry |
| 615 |
+ |
* @return {@code true} if the specified object is equal to this map |
| 616 |
+ |
* entry |
| 617 |
+ |
* @see #hashCode |
| 618 |
+ |
*/ |
| 619 |
|
public boolean equals(Object o) { |
| 620 |
|
if (!(o instanceof Map.Entry)) |
| 621 |
|
return false; |
| 623 |
|
return eq(key, e.getKey()) && eq(value, e.getValue()); |
| 624 |
|
} |
| 625 |
|
|
| 626 |
+ |
/** |
| 627 |
+ |
* Returns the hash code value for this map entry. The hash code |
| 628 |
+ |
* of a map entry {@code e} is defined to be: <pre> |
| 629 |
+ |
* (e.getKey()==null ? 0 : e.getKey().hashCode()) ^ |
| 630 |
+ |
* (e.getValue()==null ? 0 : e.getValue().hashCode())</pre> |
| 631 |
+ |
* This ensures that {@code e1.equals(e2)} implies that |
| 632 |
+ |
* {@code e1.hashCode()==e2.hashCode()} for any two Entries |
| 633 |
+ |
* {@code e1} and {@code e2}, as required by the general |
| 634 |
+ |
* contract of {@link Object#hashCode}. |
| 635 |
+ |
* |
| 636 |
+ |
* @return the hash code value for this map entry |
| 637 |
+ |
* @see #equals |
| 638 |
+ |
*/ |
| 639 |
|
public int hashCode() { |
| 640 |
|
return (key == null ? 0 : key.hashCode()) ^ |
| 641 |
|
(value == null ? 0 : value.hashCode()); |
| 726 |
|
throw new UnsupportedOperationException(); |
| 727 |
|
} |
| 728 |
|
|
| 729 |
+ |
/** |
| 730 |
+ |
* Compares the specified object with this entry for equality. |
| 731 |
+ |
* Returns {@code true} if the given object is also a map entry and |
| 732 |
+ |
* the two entries represent the same mapping. More formally, two |
| 733 |
+ |
* entries {@code e1} and {@code e2} represent the same mapping |
| 734 |
+ |
* if<pre> |
| 735 |
+ |
* (e1.getKey()==null ? |
| 736 |
+ |
* e2.getKey()==null : |
| 737 |
+ |
* e1.getKey().equals(e2.getKey())) |
| 738 |
+ |
* && |
| 739 |
+ |
* (e1.getValue()==null ? |
| 740 |
+ |
* e2.getValue()==null : |
| 741 |
+ |
* e1.getValue().equals(e2.getValue()))</pre> |
| 742 |
+ |
* This ensures that the {@code equals} method works properly across |
| 743 |
+ |
* different implementations of the {@code Map.Entry} interface. |
| 744 |
+ |
* |
| 745 |
+ |
* @param o object to be compared for equality with this map entry |
| 746 |
+ |
* @return {@code true} if the specified object is equal to this map |
| 747 |
+ |
* entry |
| 748 |
+ |
* @see #hashCode |
| 749 |
+ |
*/ |
| 750 |
|
public boolean equals(Object o) { |
| 751 |
|
if (!(o instanceof Map.Entry)) |
| 752 |
|
return false; |
| 754 |
|
return eq(key, e.getKey()) && eq(value, e.getValue()); |
| 755 |
|
} |
| 756 |
|
|
| 757 |
+ |
/** |
| 758 |
+ |
* Returns the hash code value for this map entry. The hash code |
| 759 |
+ |
* of a map entry {@code e} is defined to be: <pre> |
| 760 |
+ |
* (e.getKey()==null ? 0 : e.getKey().hashCode()) ^ |
| 761 |
+ |
* (e.getValue()==null ? 0 : e.getValue().hashCode())</pre> |
| 762 |
+ |
* This ensures that {@code e1.equals(e2)} implies that |
| 763 |
+ |
* {@code e1.hashCode()==e2.hashCode()} for any two Entries |
| 764 |
+ |
* {@code e1} and {@code e2}, as required by the general |
| 765 |
+ |
* contract of {@link Object#hashCode}. |
| 766 |
+ |
* |
| 767 |
+ |
* @return the hash code value for this map entry |
| 768 |
+ |
* @see #equals |
| 769 |
+ |
*/ |
| 770 |
|
public int hashCode() { |
| 771 |
|
return (key == null ? 0 : key.hashCode()) ^ |
| 772 |
|
(value == null ? 0 : value.hashCode()); |
