Package org.apache.commons.collections4.map

Class MultiValueMap<K,​V>

  • Type Parameters:
    K - the type of the keys in this map
    V - the type of the values in this map
    All Implemented Interfaces:
    Serializable, Map<K,​Object>, Get<K,​Object>, IterableGet<K,​Object>, IterableMap<K,​Object>, MultiMap<K,​V>, Put<K,​Object>
    @Deprecated
public class MultiValueMap<K,​V>
extends AbstractMapDecorator<K,​Object>
implements MultiMap<K,​V>, Serializable
    Deprecated.
    since 4.1, use MultiValuedMap instead
    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.

    Since:
    3.2
    See Also:
    Serialized Form

    • Constructor Detail

      • MultiValueMap

        public MultiValueMap()
        Deprecated.
        Creates a MultiValueMap based on a HashMap and storing the multiple values in an ArrayList.

      • MultiValueMap

        protected MultiValueMap​(Map<K,​? super C> map,
                        Factory<C> collectionFactory)
        Deprecated.
        Creates a MultiValueMap which decorates the given map and creates the value collections using the supplied collectionFactory.
        Type Parameters:
        C - the collection class type
        Parameters:
        map - the map to decorate
        collectionFactory - the collection factory which must return a Collection instance

    • Method Detail

      • multiValueMap

        public static <K,​V> MultiValueMap<K,​V> multiValueMap​(Map<K,​? super Collection<V>> map)
        Deprecated.
        Creates a map which wraps the given map and maps keys to ArrayLists.
        Type Parameters:
        K - the key type
        V - the value type
        Parameters:
        map - the map to wrap
        Returns:
        a new multi-value map
        Since:
        4.0

      • multiValueMap

        public static <K,​V,​C extends Collection<V>> MultiValueMap<K,​V> multiValueMap​(Map<K,​? super C> map,
                                                                                               Class<C> collectionClass)
        Deprecated.
        Creates a map which decorates the given map and maps keys to collections of type collectionClass.
        Type Parameters:
        K - the key type
        V - the value type
        C - the collection class type
        Parameters:
        map - the map to wrap
        collectionClass - the type of the collection class
        Returns:
        a new multi-value map
        Since:
        4.0

      • multiValueMap

        public static <K,​V,​C extends Collection<V>> MultiValueMap<K,​V> multiValueMap​(Map<K,​? super C> map,
                                                                                               Factory<C> collectionFactory)
        Deprecated.
        Creates a map which decorates the given map and creates the value collections using the supplied collectionFactory.
        Type Parameters:
        K - the key type
        V - the value type
        C - the collection class type
        Parameters:
        map - the map to decorate
        collectionFactory - the collection factory (must return a Collection object).
        Returns:
        a new multi-value map
        Since:
        4.0

      • removeMapping

        public boolean removeMapping​(Object key,
                             Object value)
        Deprecated.
        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 subsequent get(key).

        Specified by:
        removeMapping in interface MultiMap<K,​V>
        Parameters:
        key - the key to remove from
        value - the value to remove
        Returns:
        true if the mapping was removed, false otherwise

      • put

        public Object put​(K key,
                  Object value)
        Deprecated.
        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.

        Specified by:
        put in interface Map<K,​V>
        Specified by:
        put in interface MultiMap<K,​V>
        Specified by:
        put in interface Put<K,​V>
        Overrides:
        put in class AbstractMapDecorator<K,​Object>
        Parameters:
        key - the key to store against
        value - the value to add to the collection at the key
        Returns:
        the value added if the map changed and null if the map did not change
        See Also:
        Map.put(Object, Object)

      • putAll

        public void putAll​(Map<? extends K,​?> map)
        Deprecated.
        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).

        Specified by:
        putAll in interface Map<K,​V>
        Specified by:
        putAll in interface Put<K,​V>
        Overrides:
        putAll in class AbstractMapDecorator<K,​Object>
        Parameters:
        map - the map to copy (either a normal or multi map)
        See Also:
        Map.putAll(Map)

      • containsValue

        public boolean containsValue​(Object key,
                             Object value)
        Deprecated.
        Checks whether the collection at the specified key contains the value.
        Parameters:
        key - the key to search for
        value - the value to search for
        Returns:
        true if the map contains the value

      • getCollection

        public Collection<V> getCollection​(Object key)
        Deprecated.
        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
        Returns:
        the collection mapped to the key, null if no mapping

      • size

        public int size​(Object key)
        Deprecated.
        Gets the size of the collection mapped to the specified key.
        Parameters:
        key - the key to get size for
        Returns:
        the size of the collection at the key, zero if key not in map

      • putAll

        public boolean putAll​(K key,
                      Collection<V> values)
        Deprecated.
        Adds a collection of values to the collection associated with the specified key.
        Parameters:
        key - the key to store against
        values - the values to add to the collection at the key, null ignored
        Returns:
        true if this map changed

      • iterator

        public Iterator<V> iterator​(Object key)
        Deprecated.
        Gets an iterator for the collection mapped to the specified key.
        Parameters:
        key - the key to get an iterator for
        Returns:
        the iterator of the collection at the key, empty iterator if key not in map

      • totalSize

        public int totalSize()
        Deprecated.
        Gets the total size of the map by counting all the values.
        Returns:
        the total size of the map counting all values

      • createCollection

        protected Collection<V> createCollection​(int size)
        Deprecated.
        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
        Returns:
        the new collection