org.apache.commons.collections.keyvalue

Class DefaultKeyValue

Implemented Interfaces:
KeyValue

public class DefaultKeyValue
extends AbstractKeyValue

A mutable KeyValue pair that does not implement MapEntry.

Note that a DefaultKeyValue instance may not contain itself as a key or value.

Version:
$Revision: 1.4 $ $Date: 2004/02/18 01:00:08 $
Authors:
James Strachan
Michael A. Smith
Neil O'Toole
Stephen Colebourne
Since:
Commons Collections 3.0

Field Summary

Fields inherited from class org.apache.commons.collections.keyvalue.AbstractKeyValue

key, value

Constructor Summary

DefaultKeyValue()
Constructs a new pair with a null key and null value.
DefaultKeyValue(Map.Entry entry)
Constructs a new pair from the specified MapEntry.
DefaultKeyValue(Object key, Object value)
Constructs a new pair with the specified key and given value.
DefaultKeyValue(KeyValue pair)
Constructs a new pair from the specified KeyValue.

Method Summary

boolean
equals(Object obj)
Compares this Map Entry with another Map Entry.
int
hashCode()
Gets a hashCode compatible with the equals method.
Object
setKey(Object key)
Sets the key.
Object
setValue(Object value)
Sets the value.
Map.Entry
toMapEntry()
Returns a new Map.Entry object with key and value from this pair.

Methods inherited from class org.apache.commons.collections.keyvalue.AbstractKeyValue

getKey, getValue, toString

Constructor Details

DefaultKeyValue

public DefaultKeyValue()
Constructs a new pair with a null key and null value.

DefaultKeyValue

public DefaultKeyValue(Map.Entry entry)
Constructs a new pair from the specified MapEntry.
Parameters:
entry - the entry to copy, must not be null

DefaultKeyValue

public DefaultKeyValue(Object key,
                       Object value)
Constructs a new pair with the specified key and given value.
Parameters:
key - the key for the entry, may be null
value - the value for the entry, may be null

DefaultKeyValue

public DefaultKeyValue(KeyValue pair)
Constructs a new pair from the specified KeyValue.
Parameters:
pair - the pair to copy, must not be null

Method Details

equals

public boolean equals(Object obj)
Compares this Map Entry with another Map Entry.

Returns true if the compared object is also a DefaultKeyValue, and its key and value are equal to this object's key and value.

Parameters:
obj - the object to compare to
Returns:
true if equal key and value

hashCode

public int hashCode()
Gets a hashCode compatible with the equals method.

Implemented per API documentation of java.util.Map.Entry.hashCode(), however subclasses may override this.

Returns:
a suitable hash code

setKey

public Object setKey(Object key)
Sets the key.
Parameters:
key - the new key
Returns:
the old key

setValue

public Object setValue(Object value)
Sets the value.
Parameters:
value - the new value
Returns:
the old value of the value

toMapEntry

public Map.Entry toMapEntry()
Returns a new Map.Entry object with key and value from this pair.
Returns:
a MapEntry instance

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