harpoon.Util.Collections
Class AbstractMapEntry

java.lang.Object
  |
  +--harpoon.Util.Collections.AbstractMapEntry
All Implemented Interfaces:
Map.Entry
Direct Known Subclasses:
PairMapEntry

public abstract class AbstractMapEntry
extends Object
implements Map.Entry

An AbstractMapEntry takes care of most of the grunge work involved in subclassing java.util.Map.Entry. For an immutable entry, you need only implement getKey() and getValue(). For a modifiable entry, you must also implement setValue(); the default implementation throws an UnsupportedOperationException.

Version:
$Id: AbstractMapEntry.java,v 1.2 2002/02/25 21:09:03 cananian Exp $
Author:
C. Scott Ananian <cananian@alumni.princeton.edu>

Constructor Summary
AbstractMapEntry()
           
 
Method Summary
 boolean equals(Object o)
          Compares the specified object with this entry for equality.
abstract  Object getKey()
          Returns the key corresponding to this entry.
abstract  Object getValue()
          Returns the value corresponding to this entry.
 int hashCode()
          Returns the hash code value for this map entry.
 Object setValue(Object value)
          Replaces the value corresponding to this entry with the specified value (optional operation).
 String toString()
          Returns a human-readable representation of this map entry.
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Constructor Detail

AbstractMapEntry

public AbstractMapEntry()
Method Detail

getKey

public abstract Object getKey()
Returns the key corresponding to this entry.

Specified by:
getKey in interface Map.Entry

getValue

public abstract Object getValue()
Returns the value corresponding to this entry. If the mapping has been removed from the backing map (by the iterator's remove() operation), the results of this call are undefined.

Specified by:
getValue in interface Map.Entry

setValue

public Object setValue(Object value)
Replaces the value corresponding to this entry with the specified value (optional operation). (Writes through to the map.) The behavior of this call is undefined if the mapping has already been removed from the map (by the iterator's remove() operation).

Specified by:
setValue in interface Map.Entry
Returns:
old value corresponding to entry.

toString

public String toString()
Returns a human-readable representation of this map entry.

Overrides:
toString in class Object

equals

public boolean equals(Object o)
Compares the specified object with this entry for equality. Returns true if the given object is also a map entry and the two entries represent the same mapping.

Specified by:
equals in interface Map.Entry
Overrides:
equals in class Object

hashCode

public int hashCode()
Returns the hash code value for this map entry.

Specified by:
hashCode in interface Map.Entry
Overrides:
hashCode in class Object