Class ImmutableMap<K,​V>

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  ImmutableMap.Builder<K,​V>
      A builder for creating immutable map instances, especially public static final maps ("constant maps").
    • Method Detail

      • toImmutableMap

        public static <T extends @Nullable Object,​K,​V> Collector<T,​?,​ImmutableMap<K,​V>> toImmutableMap​(Function<? super T,​? extends K> keyFunction,
                                                                                                                                     Function<? super T,​? extends V> valueFunction)
        Returns a Collector that accumulates elements into an ImmutableMap whose keys and values are the result of applying the provided mapping functions to the input elements. Entries appear in the result ImmutableMap in encounter order.

        If the mapped keys contain duplicates (according to Object.equals(Object), an IllegalArgumentException is thrown when the collection operation is performed. (This differs from the Collector returned by Collectors.toMap(Function, Function), which throws an IllegalStateException.)

        Since:
        33.2.0 (available since 21.0 in guava-jre)
      • toImmutableMap

        public static <T extends @Nullable Object,​K,​V> Collector<T,​?,​ImmutableMap<K,​V>> toImmutableMap​(Function<? super T,​? extends K> keyFunction,
                                                                                                                                     Function<? super T,​? extends V> valueFunction,
                                                                                                                                     BinaryOperator<V> mergeFunction)
        Returns a Collector that accumulates elements into an ImmutableMap whose keys and values are the result of applying the provided mapping functions to the input elements.

        If the mapped keys contain duplicates (according to Object.equals(Object)), the values are merged using the specified merging function. If the merging function returns null, then the collector removes the value that has been computed for the key thus far (though future occurrences of the key would reinsert it).

        Entries will appear in the encounter order of the first occurrence of the key.

        Since:
        33.2.0 (available since 21.0 in guava-jre)
      • of

        public static <K,​V> ImmutableMap<K,​V> of()
        Returns the empty map. This map behaves and performs comparably to Collections.emptyMap(), and is preferable mainly for consistency and maintainability of your code.

        Performance note: the instance returned is a singleton.

      • of

        public static <K,​V> ImmutableMap<K,​V> of​(K k1,
                                                             V v1)
        Returns an immutable map containing a single entry. This map behaves and performs comparably to Collections.singletonMap(K, V) but will not accept a null key or value. It is preferable mainly for consistency and maintainability of your code.
      • of

        public static <K,​V> ImmutableMap<K,​V> of​(K k1,
                                                             V v1,
                                                             K k2,
                                                             V v2)
        Returns an immutable map containing the given entries, in order.
        Throws:
        IllegalArgumentException - if duplicate keys are provided
      • of

        public static <K,​V> ImmutableMap<K,​V> of​(K k1,
                                                             V v1,
                                                             K k2,
                                                             V v2,
                                                             K k3,
                                                             V v3)
        Returns an immutable map containing the given entries, in order.
        Throws:
        IllegalArgumentException - if duplicate keys are provided
      • of

        public static <K,​V> ImmutableMap<K,​V> of​(K k1,
                                                             V v1,
                                                             K k2,
                                                             V v2,
                                                             K k3,
                                                             V v3,
                                                             K k4,
                                                             V v4)
        Returns an immutable map containing the given entries, in order.
        Throws:
        IllegalArgumentException - if duplicate keys are provided
      • of

        public static <K,​V> ImmutableMap<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 map containing the given entries, in order.
        Throws:
        IllegalArgumentException - if duplicate keys are provided
      • of

        public static <K,​V> ImmutableMap<K,​V> of​(K k1,
                                                             V v1,
                                                             K k2,
                                                             V v2,
                                                             K k3,
                                                             V v3,
                                                             K k4,
                                                             V v4,
                                                             K k5,
                                                             V v5,
                                                             K k6,
                                                             V v6)
        Returns an immutable map containing the given entries, in order.
        Throws:
        IllegalArgumentException - if duplicate keys are provided
        Since:
        31.0
      • of

        public static <K,​V> ImmutableMap<K,​V> of​(K k1,
                                                             V v1,
                                                             K k2,
                                                             V v2,
                                                             K k3,
                                                             V v3,
                                                             K k4,
                                                             V v4,
                                                             K k5,
                                                             V v5,
                                                             K k6,
                                                             V v6,
                                                             K k7,
                                                             V v7)
        Returns an immutable map containing the given entries, in order.
        Throws:
        IllegalArgumentException - if duplicate keys are provided
        Since:
        31.0
      • of

        public static <K,​V> ImmutableMap<K,​V> of​(K k1,
                                                             V v1,
                                                             K k2,
                                                             V v2,
                                                             K k3,
                                                             V v3,
                                                             K k4,
                                                             V v4,
                                                             K k5,
                                                             V v5,
                                                             K k6,
                                                             V v6,
                                                             K k7,
                                                             V v7,
                                                             K k8,
                                                             V v8)
        Returns an immutable map containing the given entries, in order.
        Throws:
        IllegalArgumentException - if duplicate keys are provided
        Since:
        31.0
      • of

        public static <K,​V> ImmutableMap<K,​V> of​(K k1,
                                                             V v1,
                                                             K k2,
                                                             V v2,
                                                             K k3,
                                                             V v3,
                                                             K k4,
                                                             V v4,
                                                             K k5,
                                                             V v5,
                                                             K k6,
                                                             V v6,
                                                             K k7,
                                                             V v7,
                                                             K k8,
                                                             V v8,
                                                             K k9,
                                                             V v9)
        Returns an immutable map containing the given entries, in order.
        Throws:
        IllegalArgumentException - if duplicate keys are provided
        Since:
        31.0
      • of

        public static <K,​V> ImmutableMap<K,​V> of​(K k1,
                                                             V v1,
                                                             K k2,
                                                             V v2,
                                                             K k3,
                                                             V v3,
                                                             K k4,
                                                             V v4,
                                                             K k5,
                                                             V v5,
                                                             K k6,
                                                             V v6,
                                                             K k7,
                                                             V v7,
                                                             K k8,
                                                             V v8,
                                                             K k9,
                                                             V v9,
                                                             K k10,
                                                             V v10)
        Returns an immutable map containing the given entries, in order.
        Throws:
        IllegalArgumentException - if duplicate keys are provided
        Since:
        31.0
      • builderWithExpectedSize

        public static <K,​V> ImmutableMap.Builder<K,​V> builderWithExpectedSize​(int expectedSize)
        Returns a new builder, expecting the specified number of entries to be added.

        If expectedSize is exactly the number of entries added to the builder before ImmutableMap.Builder.build(boolean) is called, the builder is likely to perform better than an unsized builder() would have.

        It is not specified if any performance benefits apply if expectedSize is close to, but not exactly, the number of entries added to the builder.

        Since:
        23.1
      • copyOf

        public static <K,​V> ImmutableMap<K,​V> copyOf​(Map<? extends K,​? extends V> map)
        Returns an immutable map containing the same entries as map. The returned map iterates over entries in the same order as the entrySet of the original map. If map somehow contains entries with duplicate keys (for example, if it is a SortedMap whose comparator is not consistent with equals), the results of this method are undefined.

        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 map is null
      • copyOf

        public static <K,​V> ImmutableMap<K,​V> copyOf​(Iterable<? extends Map.Entry<? extends K,​? extends V>> entries)
        Returns an immutable map containing the specified entries. The returned map iterates over entries in the same order as the original iterable.
        Throws:
        NullPointerException - if any key, value, or entry is null
        IllegalArgumentException - if two entries have the same key
        Since:
        19.0
      • entrySet

        public ImmutableSet<Map.Entry<K,​V>> entrySet()
        Returns an immutable set of the mappings in this map. The iteration order is specified by the method used to create this map. Typically, this is insertion order.
        Specified by:
        entrySet in interface Map<K,​V>
      • keySet

        public ImmutableSet<KkeySet()
        Returns an immutable set of the keys in this map, in the same order that they appear in entrySet.
        Specified by:
        keySet in interface Map<K,​V>
      • values

        public ImmutableCollection<Vvalues()
        Returns an immutable collection of the values in this map, in the same order that they appear in entrySet.
        Specified by:
        values in interface Map<K,​V>