Class ImmutableSetMultimap<K,V>

All Implemented Interfaces:
Multimap<K,V>, SetMultimap<K,V>, Serializable
Direct Known Subclasses:
EmptyImmutableSetMultimap

public class ImmutableSetMultimap<K,V> extends ImmutableMultimap<K,V> implements SetMultimap<K,V>
A SetMultimap whose contents will never change, with many other important properties detailed at ImmutableCollection.

Warning: As in all SetMultimaps, do not modify either a key or a value of a ImmutableSetMultimap in a way that affects its Object.equals(java.lang.Object) behavior. Undefined behavior and bugs will result.

See the Guava User Guide article on immutable collections.

Since:
2.0
See Also:
  • Field Details

    • emptySet

      private final transient ImmutableSet<V> emptySet
      Returned by get() when a missing key is provided. Also holds the comparator, if any, used for values.
    • inverse

      @CheckForNull private transient ImmutableSetMultimap<V,K> inverse
    • entries

      @CheckForNull private transient ImmutableSet<Map.Entry<K,V>> entries
    • serialVersionUID

      private static final long serialVersionUID
      See Also:
  • Constructor Details

  • Method Details

    • toImmutableSetMultimap

      public static <T, K, V> Collector<T,?,ImmutableSetMultimap<K,V>> toImmutableSetMultimap(Function<? super T,? extends K> keyFunction, Function<? super T,? extends V> valueFunction)
      Returns a Collector that accumulates elements into an ImmutableSetMultimap whose keys and values are the result of applying the provided mapping functions to the input elements.

      For streams with defined encounter order (as defined in the Ordering section of the java.util.stream Javadoc), that order is preserved, but entries are grouped by key.

      Example:

      
       static final Multimap<Character, String> FIRST_LETTER_MULTIMAP =
           Stream.of("banana", "apple", "carrot", "asparagus", "cherry")
               .collect(toImmutableSetMultimap(str -> str.charAt(0), str -> str.substring(1)));
      
       // is equivalent to
      
       static final Multimap<Character, String> FIRST_LETTER_MULTIMAP =
           new ImmutableSetMultimap.Builder<Character, String>()
               .put('b', "anana")
               .putAll('a', "pple", "sparagus")
               .putAll('c', "arrot", "herry")
               .build();
       
      Since:
      21.0
    • flatteningToImmutableSetMultimap

      public static <T, K, V> Collector<T,?,ImmutableSetMultimap<K,V>> flatteningToImmutableSetMultimap(Function<? super T,? extends K> keyFunction, Function<? super T,? extends Stream<? extends V>> valuesFunction)
      Returns a Collector accumulating entries into an ImmutableSetMultimap. Each input element is mapped to a key and a stream of values, each of which are put into the resulting Multimap, in the encounter order of the stream and the encounter order of the streams of values.

      Example:

      
       static final ImmutableSetMultimap<Character, Character> FIRST_LETTER_MULTIMAP =
           Stream.of("banana", "apple", "carrot", "asparagus", "cherry")
               .collect(
                   flatteningToImmutableSetMultimap(
                        str -> str.charAt(0),
                        str -> str.substring(1).chars().mapToObj(c -> (char) c));
      
       // is equivalent to
      
       static final ImmutableSetMultimap<Character, Character> FIRST_LETTER_MULTIMAP =
           ImmutableSetMultimap.<Character, Character>builder()
               .putAll('b', Arrays.asList('a', 'n', 'a', 'n', 'a'))
               .putAll('a', Arrays.asList('p', 'p', 'l', 'e'))
               .putAll('c', Arrays.asList('a', 'r', 'r', 'o', 't'))
               .putAll('a', Arrays.asList('s', 'p', 'a', 'r', 'a', 'g', 'u', 's'))
               .putAll('c', Arrays.asList('h', 'e', 'r', 'r', 'y'))
               .build();
      
       // after deduplication, the resulting multimap is equivalent to
      
       static final ImmutableSetMultimap<Character, Character> FIRST_LETTER_MULTIMAP =
           ImmutableSetMultimap.<Character, Character>builder()
               .putAll('b', Arrays.asList('a', 'n'))
               .putAll('a', Arrays.asList('p', 'l', 'e', 's', 'a', 'r', 'g', 'u'))
               .putAll('c', Arrays.asList('a', 'r', 'o', 't', 'h', 'e', 'y'))
               .build();
       
       }
      Since:
      21.0
    • of

      public static <K, V> ImmutableSetMultimap<K,V> of()
      Returns the empty multimap.

      Performance note: the instance returned is a singleton.

    • of

      public static <K, V> ImmutableSetMultimap<K,V> of(K k1, V v1)
      Returns an immutable multimap containing a single entry.
    • of

      public static <K, V> ImmutableSetMultimap<K,V> of(K k1, V v1, K k2, V v2)
      Returns an immutable multimap containing the given entries, in order. Repeated occurrences of an entry (according to Object.equals(java.lang.Object)) after the first are ignored.
    • of

      public static <K, V> ImmutableSetMultimap<K,V> of(K k1, V v1, K k2, V v2, K k3, V v3)
      Returns an immutable multimap containing the given entries, in order. Repeated occurrences of an entry (according to Object.equals(java.lang.Object)) after the first are ignored.
    • of

      public static <K, V> ImmutableSetMultimap<K,V> of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4)
      Returns an immutable multimap containing the given entries, in order. Repeated occurrences of an entry (according to Object.equals(java.lang.Object)) after the first are ignored.
    • of

      public static <K, V> ImmutableSetMultimap<K,V> of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4, K k5, V v5)
      Returns an immutable multimap containing the given entries, in order. Repeated occurrences of an entry (according to Object.equals(java.lang.Object)) after the first are ignored.
    • builder

      public static <K, V> ImmutableSetMultimap.Builder<K,V> builder()
    • builderWithExpectedKeys

      public static <K, V> ImmutableSetMultimap.Builder<K,V> builderWithExpectedKeys(int expectedKeys)
      Returns a new builder with a hint for how many distinct keys are expected to be added. The generated builder is equivalent to that returned by builder(), but may perform better if expectedKeys is a good estimate.
      Throws:
      IllegalArgumentException - if expectedKeys is negative
      Since:
      33.3.0
    • copyOf

      public static <K, V> ImmutableSetMultimap<K,V> copyOf(Multimap<? extends K,? extends V> multimap)
      Returns an immutable set multimap containing the same mappings as multimap. The generated multimap's key and value orderings correspond to the iteration ordering of the multimap.asMap() view. Repeated occurrences of an entry in the multimap after the first are ignored.

      Despite the method name, this method attempts to avoid actually copying the data when it is safe to do so. The exact circumstances under which a copy will or will not be performed are undocumented and subject to change.

      Throws:
      NullPointerException - if any key or value in multimap is null
    • copyOf

      private static <K, V> ImmutableSetMultimap<K,V> copyOf(Multimap<? extends K,? extends V> multimap, @CheckForNull Comparator<? super V> valueComparator)
    • copyOf

      public static <K, V> ImmutableSetMultimap<K,V> copyOf(Iterable<? extends Map.Entry<? extends K,? extends V>> entries)
      Returns an immutable multimap containing the specified entries. The returned multimap iterates over keys in the order they were first encountered in the input, and the values for each key are iterated in the order they were encountered. If two values for the same key are equal, the first value encountered is used.
      Throws:
      NullPointerException - if any key, value, or entry is null
      Since:
      19.0
    • fromMapEntries

      static <K, V> ImmutableSetMultimap<K,V> fromMapEntries(Collection<? extends Map.Entry<? extends K,? extends Collection<? extends V>>> mapEntries, @CheckForNull Comparator<? super V> valueComparator)
      Creates an ImmutableSetMultimap from an asMap.entrySet.
    • fromMapBuilderEntries

      static <K, V> ImmutableSetMultimap<K,V> fromMapBuilderEntries(Collection<? extends Map.Entry<K,ImmutableCollection.Builder<V>>> mapEntries, @CheckForNull Comparator<? super V> valueComparator)
      Creates an ImmutableSetMultimap from a map to builders.
    • get

      public ImmutableSet<V> get(K key)
      Returns an immutable set of the values for the given key. If no mappings in the multimap have the provided key, an empty immutable set is returned. The values are in the same order as the parameters used to build this multimap.
      Specified by:
      get in interface Multimap<K,V>
      Specified by:
      get in interface SetMultimap<K,V>
      Specified by:
      get in class ImmutableMultimap<K,V>
    • inverse

      public ImmutableSetMultimap<V,K> inverse()
      Returns an immutable multimap which is the inverse of this one. For every key-value mapping in the original, the result will have a mapping with key and value reversed.

      Because an inverse of a set multimap cannot contain multiple pairs with the same key and value, this method returns an ImmutableSetMultimap rather than the ImmutableMultimap specified in the ImmutableMultimap class.

      Specified by:
      inverse in class ImmutableMultimap<K,V>
    • invert

      private ImmutableSetMultimap<V,K> invert()
    • removeAll

      @Deprecated public final ImmutableSet<V> removeAll(@CheckForNull Object key)
      Deprecated.
      Unsupported operation.
      Guaranteed to throw an exception and leave the multimap unmodified.
      Specified by:
      removeAll in interface Multimap<K,V>
      Specified by:
      removeAll in interface SetMultimap<K,V>
      Overrides:
      removeAll in class ImmutableMultimap<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.
      Throws:
      UnsupportedOperationException - always
    • replaceValues

      @Deprecated public final ImmutableSet<V> replaceValues(K key, Iterable<? extends V> values)
      Deprecated.
      Unsupported operation.
      Guaranteed to throw an exception and leave the multimap unmodified.
      Specified by:
      replaceValues in interface Multimap<K,V>
      Specified by:
      replaceValues in interface SetMultimap<K,V>
      Overrides:
      replaceValues in class ImmutableMultimap<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.
      Throws:
      UnsupportedOperationException - always
    • entries

      public ImmutableSet<Map.Entry<K,V>> entries()
      Returns an immutable collection of all key-value pairs in the multimap. Its iterator traverses the values for the first key, the values for the second key, and so on.
      Specified by:
      entries in interface Multimap<K,V>
      Specified by:
      entries in interface SetMultimap<K,V>
      Overrides:
      entries in class ImmutableMultimap<K,V>
    • valueSet

      private static <V> ImmutableSet<V> valueSet(@CheckForNull Comparator<? super V> valueComparator, Collection<? extends V> values)
    • emptySet

      private static <V> ImmutableSet<V> emptySet(@CheckForNull Comparator<? super V> valueComparator)
    • valuesBuilder

      private static <V> ImmutableSet.Builder<V> valuesBuilder(@CheckForNull Comparator<? super V> valueComparator)
    • writeObject

      private void writeObject(ObjectOutputStream stream) throws IOException
      Throws:
      IOException
    • valueComparator

      @CheckForNull Comparator<? super V> valueComparator()
    • readObject

      private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException
      Throws:
      IOException
      ClassNotFoundException