Class AbstractMultimap<K,V>

java.lang.Object
com.google.common.collect.AbstractMultimap<K,V>
All Implemented Interfaces:
Multimap<K,V>
Direct Known Subclasses:
AbstractMapBasedMultimap, BaseImmutableMultimap, FilteredEntryMultimap, FilteredKeyMultimap, LinkedListMultimap, Multimaps.MapMultimap, Multimaps.TransformedEntriesMultimap

abstract class AbstractMultimap<K,V> extends Object implements Multimap<K,V>
A skeleton Multimap implementation, not necessarily in terms of a Map.
  • Field Details

    • entries

      @CheckForNull private transient Collection<Map.Entry<K,V>> entries
    • keySet

      @CheckForNull private transient Set<K> keySet
    • keys

      @CheckForNull private transient Multiset<K> keys
    • values

      @CheckForNull private transient Collection<V> values
    • asMap

      @CheckForNull private transient Map<K,Collection<V>> asMap
  • Constructor Details

    • AbstractMultimap

      AbstractMultimap()
  • Method Details

    • isEmpty

      public boolean isEmpty()
      Description copied from interface: Multimap
      Returns true if this multimap contains no key-value pairs. Equivalent to size() == 0, but can in some cases be more efficient.
      Specified by:
      isEmpty in interface Multimap<K,V>
    • containsValue

      public boolean containsValue(@CheckForNull Object value)
      Description copied from interface: Multimap
      Returns true if this multimap contains at least one key-value pair with the value value.
      Specified by:
      containsValue in interface Multimap<K,V>
    • containsEntry

      public boolean containsEntry(@CheckForNull Object key, @CheckForNull Object value)
      Description copied from interface: Multimap
      Returns true if this multimap contains at least one key-value pair with the key key and the value value.
      Specified by:
      containsEntry in interface Multimap<K,V>
    • remove

      public boolean remove(@CheckForNull Object key, @CheckForNull Object value)
      Description copied from interface: Multimap
      Removes a single key-value pair with the key key and the value value from this multimap, if such exists. If multiple key-value pairs in the multimap fit this description, which one is removed is unspecified.
      Specified by:
      remove in interface Multimap<K,V>
      Returns:
      true if the multimap changed
    • put

      public boolean put(K key, V value)
      Description copied from interface: Multimap
      Stores a key-value pair in this multimap.

      Some multimap implementations allow duplicate key-value pairs, in which case put always adds a new key-value pair and increases the multimap size by 1. Other implementations prohibit duplicates, and storing a key-value pair that's already in the multimap has no effect.

      Specified by:
      put in interface Multimap<K,V>
      Returns:
      true if the method increased the size of the multimap, or false if the multimap already contained the key-value pair and doesn't allow duplicates
    • putAll

      public boolean putAll(K key, Iterable<? extends V> values)
      Description copied from interface: Multimap
      Stores a key-value pair in this multimap for each of values, all using the same key, key. Equivalent to (but expected to be more efficient than):
      
       for (V value : values) {
         put(key, value);
       }
       

      In particular, this is a no-op if values is empty.

      Specified by:
      putAll in interface Multimap<K,V>
      Returns:
      true if the multimap changed
    • putAll

      public boolean putAll(Multimap<? extends K,? extends V> multimap)
      Description copied from interface: Multimap
      Stores all key-value pairs of multimap in this multimap, in the order returned by multimap.entries().
      Specified by:
      putAll in interface Multimap<K,V>
      Returns:
      true if the multimap changed
    • replaceValues

      public Collection<V> replaceValues(K key, Iterable<? extends V> values)
      Description copied from interface: Multimap
      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).

      Specified by:
      replaceValues in interface Multimap<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.
    • entries

      public Collection<Map.Entry<K,V>> entries()
      Description copied from interface: Multimap
      Returns a view collection of all key-value pairs contained in this multimap, as Map.Entry instances.

      Changes to the returned collection or the entries it contains will update the underlying multimap, and vice versa. However, adding to the returned collection is not possible.

      Specified by:
      entries in interface Multimap<K,V>
    • createEntries

      abstract Collection<Map.Entry<K,V>> createEntries()
    • entryIterator

      abstract Iterator<Map.Entry<K,V>> entryIterator()
    • entrySpliterator

      Spliterator<Map.Entry<K,V>> entrySpliterator()
    • keySet

      public Set<K> keySet()
      Description copied from interface: Multimap
      Returns a view collection of all distinct keys contained in this multimap. Note that the key set contains a key if and only if this multimap maps that key to at least one value.

      Changes to the returned set will update the underlying multimap, and vice versa. However, adding to the returned set is not possible.

      Specified by:
      keySet in interface Multimap<K,V>
    • createKeySet

      abstract Set<K> createKeySet()
    • keys

      public Multiset<K> keys()
      Description copied from interface: Multimap
      Returns a view collection containing the key from each key-value pair in this multimap, without collapsing duplicates. This collection has the same size as this multimap, and keys().count(k) == get(k).size() for all k.

      Changes to the returned multiset will update the underlying multimap, and vice versa. However, adding to the returned collection is not possible.

      Specified by:
      keys in interface Multimap<K,V>
    • createKeys

      abstract Multiset<K> createKeys()
    • values

      public Collection<V> values()
      Description copied from interface: Multimap
      Returns a view collection containing the value from each key-value pair contained in this multimap, without collapsing duplicates (so values().size() == size()).

      Changes to the returned collection will update the underlying multimap, and vice versa. However, adding to the returned collection is not possible.

      Specified by:
      values in interface Multimap<K,V>
    • createValues

      abstract Collection<V> createValues()
    • valueIterator

      Iterator<V> valueIterator()
    • valueSpliterator

      Spliterator<V> valueSpliterator()
    • asMap

      public Map<K,Collection<V>> asMap()
      Description copied from interface: Multimap
      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.

      Specified by:
      asMap in interface Multimap<K,V>
    • createAsMap

      abstract Map<K,Collection<V>> createAsMap()
    • equals

      public boolean equals(@CheckForNull Object object)
      Description copied from interface: Multimap
      Compares the specified object with this multimap for equality. Two multimaps are equal when their map views, as returned by Multimap.asMap(), are also equal.

      In general, two multimaps with identical key-value mappings may or may not be equal, depending on the implementation. For example, two SetMultimap instances with the same key-value mappings are equal, but equality of two ListMultimap instances depends on the ordering of the values for each key.

      A non-empty SetMultimap cannot be equal to a non-empty ListMultimap, since their Multimap.asMap() views contain unequal collections as values. However, any two empty multimaps are equal, because they both have empty Multimap.asMap() views.

      Specified by:
      equals in interface Multimap<K,V>
      Overrides:
      equals in class Object
    • hashCode

      public int hashCode()
      Returns the hash code for this multimap.

      The hash code of a multimap is defined as the hash code of the map view, as returned by Multimap.asMap().

      Specified by:
      hashCode in interface Multimap<K,V>
      Overrides:
      hashCode in class Object
      See Also:
    • toString

      public String toString()
      Returns a string representation of the multimap, generated by calling toString on the map returned by Multimap.asMap().
      Overrides:
      toString in class Object
      Returns:
      a string representation of the multimap