| java.lang.Object
 org.apache.commons.collections.map.AbstractMapDecorator
org.apache.commons.collections.map.MultiValueMap
| MultiValueMap | | public class MultiValueMap extends AbstractMapDecorator implements MultiMap(Code) | | A MultiValueMap decorates another map, allowing it to have
more than one value for a key.
A MultiMap is a Map with slightly different semantics.
Putting a value into the map will add the value to a Collection at that key.
Getting a value will return a Collection, holding all the values put to that key.
This implementation is a decorator, allowing any Map implementation
to be used as the base.
In addition, this implementation allows the type of collection used
for the values to be controlled. By default, an ArrayList
is used, however a Class to instantiate may be specified,
or a factory that returns a Collection instance.
Note that MultiValueMap is not synchronized and is not thread-safe.
If you wish to use this map from multiple threads concurrently, you must use
appropriate synchronization. This class may throw exceptions when accessed
by concurrent threads without synchronization.
author:
James Carman
author:
Christopher Berry
author:
James Strachan
author:
Steve Downey
author:
Stephen Colebourne
author:
Julien Buret
author:
Serhiy Yevtushenko
version:
$Revision: 348007 $ $Date: 2005-11-21 22:52:57 +0000 (Mon, 21 Nov 2005) $
since:
Commons Collections 3.2 |
| Constructor Summary | |
| public | MultiValueMap()
Creates a MultiValueMap based on a HashMap and
storing the multiple values in an ArrayList. | | protected | MultiValueMap(Map map, Factory collectionFactory)
Creates a MultiValueMap which decorates the given map and
creates the value collections using the supplied collectionFactory. |
| Method Summary | |
| public void | clear()
Clear the map. | | public boolean | containsValue(Object value)
Checks whether the map contains the value specified. | | public boolean | containsValue(Object key, Object value)
Checks whether the collection at the specified key contains the value. | | protected Collection | createCollection(int size)
Creates a new instance of the map value Collection container
using the factory. | | public static MultiValueMap | decorate(Map map)
Creates a map which wraps the given map and
maps keys to ArrayLists. | | public static MultiValueMap | decorate(Map map, Class collectionClass)
Creates a map which decorates the given map and
maps keys to collections of type collectionClass. | | public static MultiValueMap | decorate(Map map, Factory collectionFactory)
Creates a map which decorates the given map and
creates the value collections using the supplied collectionFactory. | | public Collection | getCollection(Object key)
Gets the collection mapped to the specified key. | | public Iterator | iterator(Object key)
Gets an iterator for the collection mapped to the specified key. | | public Object | put(Object key, Object value)
Adds the value to the collection associated with the specified key. | | public void | putAll(Map map)
Override superclass to ensure that MultiMap instances are
correctly handled. | | public boolean | putAll(Object key, Collection values)
Adds a collection of values to the collection associated with
the specified key. | | public Object | remove(Object key, Object value)
Removes a specific value from map. | | public int | size(Object key)
Gets the size of the collection mapped to the specified key. | | public int | totalSize()
Gets the total size of the map by counting all the values. | | public Collection | values()
Gets a collection containing all the values in the map. |
| MultiValueMap | | public MultiValueMap()(Code) | | Creates a MultiValueMap based on a HashMap and
storing the multiple values in an ArrayList.
|
| MultiValueMap | | protected MultiValueMap(Map map, Factory collectionFactory)(Code) | | Creates a MultiValueMap which decorates the given map and
creates the value collections using the supplied collectionFactory.
Parameters:
map - the map to decorate
Parameters:
collectionFactory - the collection factory which must return a Collection instance |
| clear | | public void clear()(Code) | | Clear the map.
|
| containsValue | | public boolean containsValue(Object value)(Code) | | Checks whether the map contains the value specified.
This checks all collections against all keys for the value, and thus could be slow.
Parameters:
value - the value to search for true if the map contains the value |
| containsValue | | public boolean containsValue(Object key, Object value)(Code) | | Checks whether the collection at the specified key contains the value.
Parameters:
value - the value to search for true if the map contains the value |
| createCollection | | protected Collection createCollection(int size)(Code) | | Creates a new instance of the map value Collection container
using the factory.
This method can be overridden to perform your own processing
instead of using the factory.
Parameters:
size - the collection size that is about to be added the new collection |
| decorate | | public static MultiValueMap decorate(Map map)(Code) | | Creates a map which wraps the given map and
maps keys to ArrayLists.
Parameters:
map - the map to wrap |
| decorate | | public static MultiValueMap decorate(Map map, Class collectionClass)(Code) | | Creates a map which decorates the given map and
maps keys to collections of type collectionClass.
Parameters:
map - the map to wrap
Parameters:
collectionClass - the type of the collection class |
| decorate | | public static MultiValueMap decorate(Map map, Factory collectionFactory)(Code) | | Creates a map which decorates the given map and
creates the value collections using the supplied collectionFactory.
Parameters:
map - the map to decorate
Parameters:
collectionFactory - the collection factory (must return a Collection object). |
| getCollection | | public Collection getCollection(Object key)(Code) | | Gets the collection mapped to the specified key.
This method is a convenience method to typecast the result of get(key).
Parameters:
key - the key to retrieve the collection mapped to the key, null if no mapping |
| iterator | | public Iterator iterator(Object key)(Code) | | Gets an iterator for the collection mapped to the specified key.
Parameters:
key - the key to get an iterator for the iterator of the collection at the key, empty iterator if key not in map |
| put | | public Object put(Object key, Object value)(Code) | | Adds the value to the collection associated with the specified key.
Unlike a normal Map the previous value is not replaced.
Instead the new value is added to the collection stored against the key.
Parameters:
key - the key to store against
Parameters:
value - the value to add to the collection at the key the value added if the map changed and null if the map did not change |
| putAll | | public void putAll(Map map)(Code) | | Override superclass to ensure that MultiMap instances are
correctly handled.
If you call this method with a normal map, each entry is
added using put(Object,Object).
If you call this method with a multi map, each entry is
added using putAll(Object,Collection).
Parameters:
map - the map to copy (either a normal or multi map) |
| putAll | | public boolean putAll(Object key, Collection values)(Code) | | Adds a collection of values to the collection associated with
the specified key.
Parameters:
key - the key to store against
Parameters:
values - the values to add to the collection at the key, null ignored true if this map changed |
| remove | | public Object remove(Object key, Object value)(Code) | | Removes a specific value from map.
The item is removed from the collection mapped to the specified key.
Other values attached to that key are unaffected.
If the last value for a key is removed, null will be returned
from a subsequant get(key).
Parameters:
key - the key to remove from
Parameters:
value - the value to remove the value removed (which was passed in), null if nothing removed |
| size | | public int size(Object key)(Code) | | Gets the size of the collection mapped to the specified key.
Parameters:
key - the key to get size for the size of the collection at the key, zero if key not in map |
| totalSize | | public int totalSize()(Code) | | Gets the total size of the map by counting all the values.
the total size of the map counting all values |
| values | | public Collection values()(Code) | | Gets a collection containing all the values in the map.
This returns a collection containing the combination of values from all keys.
a collection view of the values contained in this map |
| Fields inherited from org.apache.commons.collections.map.AbstractMapDecorator | protected transient Map map(Code)(Java Doc)
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