org.apache.commons.collections.map

Class TransformedMap

public class TransformedMap extends AbstractInputCheckedMapDecorator implements Serializable

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.

Note that TransformedMap is not synchronized and is not thread-safe. If you wish to use this map from multiple threads concurrently, you must use appropriate synchronization. The simplest approach is to wrap this map using java.util.Collections#synchronizedMap(Map). This class may throw exceptions when accessed by concurrent threads without synchronization.

This class is Serializable from Commons Collections 3.1.

Since: Commons Collections 3.0

Version: $Revision: 348013 $ $Date: 2005-11-21 23:24:45 +0000 (Mon, 21 Nov 2005) $

Author: Stephen Colebourne

Field Summary
protected TransformerkeyTransformer
The transformer to use for the key
protected TransformervalueTransformer
The transformer to use for the value
Constructor Summary
protected TransformedMap(Map map, Transformer keyTransformer, Transformer valueTransformer)
Constructor that wraps (not copies).
Method Summary
protected ObjectcheckSetValue(Object value)
Override to transform the value when using setValue.
static Mapdecorate(Map map, Transformer keyTransformer, Transformer valueTransformer)
Factory method to create a transforming map.
static MapdecorateTransform(Map map, Transformer keyTransformer, Transformer valueTransformer)
Factory method to create a transforming map that will transform existing contents of the specified map.
protected booleanisSetValueChecking()
Override to only return true when there is a value transformer.
Objectput(Object key, Object value)
voidputAll(Map mapToCopy)
protected ObjecttransformKey(Object object)
Transforms a key.
protected MaptransformMap(Map map)
Transforms a map.
protected ObjecttransformValue(Object object)
Transforms a value.

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

checkSetValue

protected Object checkSetValue(Object value)
Override to transform the value when using setValue.

Parameters: value the value to transform

Returns: the transformed value

Since: Commons Collections 3.1

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. Constrast this with TransformedMap.

Parameters: map the map to decorate, must not be null keyTransformer the transformer to use for key conversion, null means no transformation valueTransformer the transformer to use for value conversion, null means no transformation

Throws: IllegalArgumentException if map is null

decorateTransform

public static Map decorateTransform(Map map, Transformer keyTransformer, Transformer valueTransformer)
Factory method to create a transforming map that will transform existing contents of the specified map.

If there are any elements already in the map being decorated, they will be transformed by this method. Constrast this with TransformedMap.

Parameters: map the map to decorate, must not be null keyTransformer the transformer to use for key conversion, null means no transformation valueTransformer the transformer to use for value conversion, null means no transformation

Throws: IllegalArgumentException if map is null

Since: Commons Collections 3.2

isSetValueChecking

protected boolean isSetValueChecking()
Override to only return true when there is a value transformer.

Returns: true if a value transformer is in use

Since: Commons Collections 3.1

put

public Object put(Object key, Object value)

putAll

public void putAll(Map mapToCopy)

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

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

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

Copyright © 2001-2008 Apache Software Foundation. All Rights Reserved.