org.apache.commons.collections.keyvalue

Class DefaultKeyValue

public class DefaultKeyValue extends AbstractKeyValue

A mutable KeyValue pair that does not implement java.util.Map.Entry Map.Entry.

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

Since: Commons Collections 3.0

Version: $Revision: 405927 $ $Date: 2006-05-12 23:57:03 +0100 (Fri, 12 May 2006) $

Author: James Strachan Michael A. Smith Neil O'Toole Stephen Colebourne

Constructor Summary
DefaultKeyValue()
Constructs a new pair with a null key and null value.
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.
DefaultKeyValue(Entry entry)
Constructs a new pair from the specified Map.Entry.
Method Summary
booleanequals(Object obj)
Compares this Map.Entry with another Map.Entry.
inthashCode()
Gets a hashCode compatible with the equals method.
ObjectsetKey(Object key)
Sets the key.
ObjectsetValue(Object value)
Sets the value.
EntrytoMapEntry()
Returns a new Map.Entry object with key and value from this pair.

Constructor Detail

DefaultKeyValue

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

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

Throws: NullPointerException if the entry is null

DefaultKeyValue

public DefaultKeyValue(Entry entry)
Constructs a new pair from the specified Map.Entry.

Parameters: entry the entry to copy, must not be null

Throws: NullPointerException if the entry is null

Method Detail

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

Throws: IllegalArgumentException if key is this object

setValue

public Object setValue(Object value)
Sets the value.

Parameters: value the new value

Returns: the old value of the value

Throws: IllegalArgumentException if value is this object

toMapEntry

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

Returns: a MapEntry instance

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