org.apache.commons.collections.map
Class TransformedMap

java.lang.Object
  |
  +--org.apache.commons.collections.map.AbstractMapDecorator
        |
        +--org.apache.commons.collections.map.TransformedMap
All Implemented Interfaces:
Map
Direct Known Subclasses:
TransformedSortedMap

public class TransformedMap
extends AbstractMapDecorator

Decorates another Map to transform objects that are added.

The Map put methods and Map.Entry setValue method are affected by this class. Thus objects must be removed or searched for using their transformed form. For example, if the transformation converts Strings to Integers, you must use the Integer form to remove objects.

Since:
Commons Collections 3.0
Version:
$Revision: 1.5 $ $Date: 2004/01/14 21:43:10 $
Author:
Stephen Colebourne

Inner classes inherited from class java.util.Map
Map.Entry
 
Field Summary
protected  Transformer keyTransformer
          The transformer to use for the key
protected  Transformer valueTransformer
          The transformer to use for the value
 
Fields inherited from class org.apache.commons.collections.map.AbstractMapDecorator
map
 
Constructor Summary
protected TransformedMap(Map map, Transformer keyTransformer, Transformer valueTransformer)
          Constructor that wraps (not copies).
 
Method Summary
static Map decorate(Map map, Transformer keyTransformer, Transformer valueTransformer)
          Factory method to create a transforming map.
 Set entrySet()
           
 Object put(Object key, Object value)
           
 void putAll(Map mapToCopy)
           
protected  Object transformKey(Object object)
          Transforms a key.
protected  Map transformMap(Map map)
          Transforms a map.
protected  Object transformValue(Object object)
          Transforms a value.
 
Methods inherited from class org.apache.commons.collections.map.AbstractMapDecorator
clear, containsKey, containsValue, equals, get, getMap, hashCode, isEmpty, keySet, remove, size, toString, values
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

keyTransformer

protected final Transformer keyTransformer
The transformer to use for the key

valueTransformer

protected final Transformer valueTransformer
The transformer to use for the value
Constructor Detail

TransformedMap

protected TransformedMap(Map map,
                         Transformer keyTransformer,
                         Transformer valueTransformer)
Constructor that wraps (not copies).

If there are any elements already in the collection being decorated, they are NOT transformed.

Parameters:
map - the map to decorate, must not be null
keyTransformer - the transformer to use for key conversion, null means no conversion
valueTransformer - the transformer to use for value conversion, null means no conversion
Throws:
IllegalArgumentException - if map is null
Method Detail

decorate

public static Map decorate(Map map,
                           Transformer keyTransformer,
                           Transformer valueTransformer)
Factory method to create a transforming map.

If there are any elements already in the map being decorated, they are NOT transformed.

Parameters:
map - the map to decorate, must not be null
keyTransformer - the transformer to use for key conversion, null means no conversion
valueTransformer - the transformer to use for value conversion, null means no conversion
Throws:
IllegalArgumentException - if map is null

transformKey

protected Object transformKey(Object object)
Transforms a key.

The transformer itself may throw an exception if necessary.

Parameters:
object - the object to transform
Throws:
the - transformed object

transformValue

protected Object transformValue(Object object)
Transforms a value.

The transformer itself may throw an exception if necessary.

Parameters:
object - the object to transform
Throws:
the - transformed object

transformMap

protected Map transformMap(Map map)
Transforms a map.

The transformer itself may throw an exception if necessary.

Parameters:
map - the map to transform
Throws:
the - transformed object

put

public Object put(Object key,
                  Object value)
Overrides:
put in class AbstractMapDecorator

putAll

public void putAll(Map mapToCopy)
Overrides:
putAll in class AbstractMapDecorator

entrySet

public Set entrySet()
Overrides:
entrySet in class AbstractMapDecorator


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