Class ImmutableListMultimap<K,V>

java.lang.Object
com.google.common.collect.ImmutableMultimap<K,V>
com.google.common.collect.ImmutableListMultimap<K,V>
All Implemented Interfaces:
ListMultimap<K,V>, Multimap<K,V>, Serializable
@GwtCompatible(serializable=true, emulated=true) public class ImmutableListMultimap<K,V> extends ImmutableMultimap<K,V> implements ListMultimap<K,V>
A ListMultimap whose contents will never change, with many other important properties detailed at ImmutableCollection.

See the Guava User Guide article on immutable collections.

Since:
2.0
Author:
Jared Levy
See Also:

  • Method Details

    • toImmutableListMultimap

      public static <T extends @Nullable Object, K, V> Collector<T,?,ImmutableListMultimap<K,V>> toImmutableListMultimap(Function<? super T,? extends K> keyFunction, Function<? super T,? extends V> valueFunction)
      Returns a Collector that accumulates elements into an ImmutableListMultimap 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(toImmutableListMultimap(str -> str.charAt(0), str -> str.substring(1)));

 // is equivalent to

 static final Multimap<Character, String> FIRST_LETTER_MULTIMAP =
     new ImmutableListMultimap.Builder<Character, String>()
         .put('b', "anana")
         .putAll('a', "pple", "sparagus")
         .putAll('c', "arrot", "herry")
         .build();
      Since:
      21.0

    • flatteningToImmutableListMultimap

      public static <T extends @Nullable Object, K, V> Collector<T,?,ImmutableListMultimap<K,V>> flatteningToImmutableListMultimap(Function<? super T,? extends K> keyFunction, Function<? super T,? extends Stream<? extends V>> valuesFunction)
      Returns a Collector accumulating entries into an ImmutableListMultimap. 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 ImmutableListMultimap<Character, Character> FIRST_LETTER_MULTIMAP =
     Stream.of("banana", "apple", "carrot", "asparagus", "cherry")
         .collect(
             flatteningToImmutableListMultimap(
                  str -> str.charAt(0),
                  str -> str.substring(1).chars().mapToObj(c -> (char) c));

 // is equivalent to

 static final ImmutableListMultimap<Character, Character> FIRST_LETTER_MULTIMAP =
     ImmutableListMultimap.<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();
 
 }
      Since:
      21.0

    • of

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

      Performance note: the instance returned is a singleton.

    • of

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

    • of

      public static <K, V> ImmutableListMultimap<K,V> of(K k1, V v1, K k2, V v2)
      Returns an immutable multimap containing the given entries, in order.

    • of

      public static <K, V> ImmutableListMultimap<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.

    • of

      public static <K, V> ImmutableListMultimap<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.

    • of

      public static <K, V> ImmutableListMultimap<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.

    • builder

      public static <K, V> ImmutableListMultimap.Builder<K,V> builder()
      Returns a new builder. The generated builder is equivalent to the builder created by the ImmutableListMultimap.Builder constructor.

    • builderWithExpectedKeys

      public static <K, V> ImmutableListMultimap.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> ImmutableListMultimap<K,V> copyOf(Multimap<? extends K,? extends V> multimap)
      Returns an immutable 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.

      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

      public static <K, V> ImmutableListMultimap<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.
      Throws:
      NullPointerException - if any key, value, or entry is null
      Since:
      19.0

    • get

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

    • inverse

      public ImmutableListMultimap<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 list multimap can contain multiple pairs with the same key and value, this method returns an ImmutableListMultimap rather than the ImmutableMultimap specified in the ImmutableMultimap class.

      Specified by:
      inverse in class ImmutableMultimap<K,V>
      Since:
      11.0

    • removeAll

      @CanIgnoreReturnValue @Deprecated public final ImmutableList<V> removeAll(@Nullable Object key)
      Deprecated.
      Unsupported operation.
      Guaranteed to throw an exception and leave the multimap unmodified.
      Specified by:
      removeAll in interface ListMultimap<K,V>
      Specified by:
      removeAll in interface Multimap<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

      @CanIgnoreReturnValue @Deprecated public final ImmutableList<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 ListMultimap<K,V>
      Specified by:
      replaceValues in interface Multimap<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

    • 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 extends @Nullable Object,V extends @Nullable Object>

    • containsEntry

      public boolean containsEntry(@Nullable Object key, @Nullable 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 extends @Nullable Object,V extends @Nullable Object>

    • equals

      public boolean equals(@Nullable 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 extends @Nullable Object,V extends @Nullable Object>
      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 extends @Nullable Object,V extends @Nullable Object>
      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