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java.util

Class AbstractMap.SimpleEntry<K,V>

Enclosing Class:
AbstractMap<K,V>
Implemented Interfaces:
Entry, Serializable
public static class AbstractMap.SimpleEntry<K,V>
extends Object
implements Entry, Serializable
A class which implements Map.Entry. It is shared by HashMap, TreeMap, Hashtable, and Collections. It is not specified by the JDK, but makes life much easier.
Since:
1.6
See Also:
Serialized Form

Constructor Summary

SimpleEntry(K newKey, V newValue)
Basic constructor initializes the fields.
SimpleEntry(extends K, V> entry)

Method Summary

boolean
equals(Object o)
Compares the specified object with this entry.
K
getKey()
Get the key corresponding to this entry.
V
getValue()
Get the value corresponding to this entry.
int
hashCode()
Returns the hash code of the entry.
V
setValue(V newVal)
Replaces the value with the specified object.
String
toString()
This provides a string representation of the entry.

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

SimpleEntry

public SimpleEntry(K newKey,
                   V newValue)
Basic constructor initializes the fields.
Parameters:
newKey - the key
newValue - the value

SimpleEntry

public SimpleEntry(extends K,
                   V> entry)

Method Details

equals

public boolean equals(Object o)
Compares the specified object with this entry. Returns true only if the object is a mapping of identical key and value. In other words, this must be:
(o instanceof Map.Entry)
       && (getKey() == null ? ((HashMap) o).getKey() == null
           : getKey().equals(((HashMap) o).getKey()))
       && (getValue() == null ? ((HashMap) o).getValue() == null
           : getValue().equals(((HashMap) o).getValue()))
Overrides:
equals in interface Object
Parameters:
o - the object to compare
Returns:
true if it is equal

getKey

public K getKey()
Get the key corresponding to this entry.
Returns:
the key

getValue

public V getValue()
Get the value corresponding to this entry. If you already called Iterator.remove(), the behavior undefined, but in this case it works.
Returns:
the value

hashCode

public int hashCode()
Returns the hash code of the entry. This is defined as the exclusive-or of the hashcodes of the key and value (using 0 for null). In other words, this must be:
(getKey() == null ? 0 : getKey().hashCode())
       ^ (getValue() == null ? 0 : getValue().hashCode())
Overrides:
hashCode in interface Object
Returns:
the hash code

setValue

public V setValue(V newVal)
Replaces the value with the specified object. This writes through to the map, unless you have already called Iterator.remove(). It may be overridden to restrict a null value.
Parameters:
newVal - the new value to store
Returns:
the old value
Throws:
NullPointerException - if the map forbids null values.
UnsupportedOperationException - if the map doesn't support put().
ClassCastException - if the value is of a type unsupported by the map.
IllegalArgumentException - if something else about this value prevents it being stored in the map.

toString

public String toString()
This provides a string representation of the entry. It is of the form "key=value", where string concatenation is used on key and value.
Overrides:
toString in interface Object
Returns:
the string representation
AbstractMap.java -- Abstract implementation of most of Map Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004, 2005 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.

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