Class AbstractListMultimap<K,V>

All Implemented Interfaces:
ListMultimap<K,V>, Multimap<K,V>, Serializable
Direct Known Subclasses:
ArrayListMultimapGwtSerializationDependencies, Multimaps.CustomListMultimap

abstract class AbstractListMultimap<K,V> extends AbstractMapBasedMultimap<K,V> implements ListMultimap<K,V>
Basic implementation of the ListMultimap interface. It's a wrapper around AbstractMapBasedMultimap that converts the returned collections into Lists. The createCollection() method must return a List.
Since:
2.0
  • Field Details

  • Constructor Details

    • AbstractListMultimap

      protected AbstractListMultimap(Map<K,Collection<V>> map)
      Creates a new multimap that uses the provided map.
      Parameters:
      map - place to store the mapping from each key to its corresponding values
  • Method Details

    • createCollection

      abstract List<V> createCollection()
      Description copied from class: AbstractMapBasedMultimap
      Creates the collection of values for a single key.

      Collections with weak, soft, or phantom references are not supported. Each call to createCollection should create a new instance.

      The returned collection class determines whether duplicate key-value pairs are allowed.

      Specified by:
      createCollection in class AbstractMapBasedMultimap<K,V>
      Returns:
      an empty collection of values
    • createUnmodifiableEmptyCollection

      List<V> createUnmodifiableEmptyCollection()
      Description copied from class: AbstractMapBasedMultimap
      Creates an unmodifiable, empty collection of values.

      This is used in AbstractMapBasedMultimap.removeAll(java.lang.Object) on an empty key.

      Overrides:
      createUnmodifiableEmptyCollection in class AbstractMapBasedMultimap<K,V>
    • unmodifiableCollectionSubclass

      <E> Collection<E> unmodifiableCollectionSubclass(Collection<E> collection)
      Overrides:
      unmodifiableCollectionSubclass in class AbstractMapBasedMultimap<K,V>
    • wrapCollection

      Collection<V> wrapCollection(K key, Collection<V> collection)
      Description copied from class: AbstractMapBasedMultimap
      Generates a decorated collection that remains consistent with the values in the multimap for the provided key. Changes to the multimap may alter the returned collection, and vice versa.
      Overrides:
      wrapCollection in class AbstractMapBasedMultimap<K,V>
    • get

      public List<V> get(K key)
      Returns a view collection of the values associated with key in this multimap, if any. Note that when containsKey(key) is false, this returns an empty collection, not null.

      Changes to the returned collection will update the underlying multimap, and vice versa.

      The returned collection is not serializable.

      Because the values for a given key may have duplicates and follow the insertion ordering, this method returns a List, instead of the Collection specified in the Multimap interface.

      Specified by:
      get in interface ListMultimap<K,V>
      Specified by:
      get in interface Multimap<K,V>
      Overrides:
      get in class AbstractMapBasedMultimap<K,V>
    • removeAll

      public List<V> removeAll(@CheckForNull Object key)
      Removes all values associated with the key key.

      Once this method returns, key will not be mapped to any values, so it will not appear in Multimap.keySet(), Multimap.asMap(), or any other views.

      The returned collection is immutable.

      Because the values for a given key may have duplicates and follow the insertion ordering, this method returns a List, instead of the Collection specified in the Multimap interface.

      Specified by:
      removeAll in interface ListMultimap<K,V>
      Specified by:
      removeAll in interface Multimap<K,V>
      Overrides:
      removeAll in class AbstractMapBasedMultimap<K,V>
      Returns:
      the values that were removed (possibly empty). The returned collection may be modifiable, but updating it will have no effect on the multimap.
    • replaceValues

      public List<V> replaceValues(K key, Iterable<? extends V> values)
      Stores a collection of values with the same key, replacing any existing values for that key.

      If values is empty, this is equivalent to removeAll(key).

      The returned collection is immutable.

      Because the values for a given key may have duplicates and follow the insertion ordering, this method returns a List, instead of the Collection specified in the Multimap interface.

      Specified by:
      replaceValues in interface ListMultimap<K,V>
      Specified by:
      replaceValues in interface Multimap<K,V>
      Overrides:
      replaceValues in class AbstractMapBasedMultimap<K,V>
      Returns:
      the collection of replaced values, or an empty collection if no values were previously associated with the key. The collection may be modifiable, but updating it will have no effect on the multimap.
    • put

      public boolean put(K key, V value)
      Stores a key-value pair in the multimap.
      Specified by:
      put in interface Multimap<K,V>
      Overrides:
      put in class AbstractMapBasedMultimap<K,V>
      Parameters:
      key - key to store in the multimap
      value - value to store in the multimap
      Returns:
      true always
    • asMap

      public Map<K,Collection<V>> asMap()
      Returns a view of this multimap as a Map from each distinct key to the nonempty collection of that key's associated values. Note that this.asMap().get(k) is equivalent to this.get(k) only when k is a key contained in the multimap; otherwise it returns null as opposed to an empty collection.

      Changes to the returned map or the collections that serve as its values will update the underlying multimap, and vice versa. The map does not support put or putAll, nor do its entries support setValue.

      Though the method signature doesn't say so explicitly, the returned map has List values.

      Specified by:
      asMap in interface ListMultimap<K,V>
      Specified by:
      asMap in interface Multimap<K,V>
      Overrides:
      asMap in class AbstractMultimap<K,V>
    • equals

      public boolean equals(@CheckForNull Object object)
      Compares the specified object to this multimap for equality.

      Two ListMultimap instances are equal if, for each key, they contain the same values in the same order. If the value orderings disagree, the multimaps will not be considered equal.

      Specified by:
      equals in interface ListMultimap<K,V>
      Specified by:
      equals in interface Multimap<K,V>
      Overrides:
      equals in class AbstractMultimap<K,V>