Class ImmutableMap.Builder<K,V>

java.lang.Object
com.google.common.collect.ImmutableMap.Builder<K,V>
Direct Known Subclasses:
ImmutableBiMap.Builder, ImmutableSortedMap.Builder
Enclosing class:
ImmutableMap<K,V>

public static class ImmutableMap.Builder<K,V> extends Object
A builder for creating immutable map instances, especially public static final maps ("constant maps"). Example:
   

   static final ImmutableMap<String, Integer> WORD_TO_INT =
       new ImmutableMap.Builder<String, Integer>()
           .put("one", 1)
           .put("two", 2)
           .put("three", 3)
           .build();

For small immutable maps, the ImmutableMap.of() methods are even more convenient.

Builder instances can be reused - it is safe to call build() multiple times to build multiple maps in series. Each map is a superset of the maps created before it.

Since:
2.0
  • Constructor Details

    • Builder

      public Builder()
      Creates a new builder. The returned builder is equivalent to the builder generated by ImmutableMap.builder().
  • Method Details

    • put

      public ImmutableMap.Builder<K,V> put(K key, V value)
      Associates key with value in the built map. Duplicate keys are not allowed, and will cause build() to fail.
    • put

      public ImmutableMap.Builder<K,V> put(Map.Entry<? extends K,? extends V> entry)
      Adds the given entry to the map, making it immutable if necessary. Duplicate keys are not allowed, and will cause build() to fail.
      Since:
      11.0
    • putAll

      public ImmutableMap.Builder<K,V> putAll(Map<? extends K,? extends V> map)
      Associates all of the given map's keys and values in the built map. Duplicate keys are not allowed, and will cause build() to fail.
      Throws:
      NullPointerException - if any key or value in map is null
    • putAll

      @Beta public ImmutableMap.Builder<K,V> putAll(Iterable<? extends Map.Entry<? extends K,? extends V>> entries)
      Adds all of the given entries to the built map. Duplicate keys are not allowed, and will cause build() to fail.
      Throws:
      NullPointerException - if any key, value, or entry is null
      Since:
      19.0
    • orderEntriesByValue

      @Beta public ImmutableMap.Builder<K,V> orderEntriesByValue(Comparator<? super V> valueComparator)
      Configures this Builder to order entries by value according to the specified comparator.

      The sort order is stable, that is, if two entries have values that compare as equivalent, the entry that was inserted first will be first in the built map's iteration order.

      Throws:
      IllegalStateException - if this method was already called
      Since:
      19.0
    • build

      public ImmutableMap<K,V> build()
      Returns a newly-created immutable map.
      Throws:
      IllegalArgumentException - if duplicate keys were added