public static class ImmutableMap.Builder<K,V> extends Object
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.
By default, a Builder
will generate maps that iterate over entries in the order they
were inserted into the builder, equivalently to LinkedHashMap
. For example, in the
above example, WORD_TO_INT.entrySet()
is guaranteed to iterate over the entries in the
order "one"=1, "two"=2, "three"=3
, and keySet()
and values()
respect
the same order. If you want a different order, consider using ImmutableSortedMap
to
sort by keys, or call orderEntriesByValue(Comparator)
, which changes this builder to
sort entries by value.
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.
Constructor and Description |
---|
Builder()
Creates a new builder.
|
Modifier and Type | Method and Description |
---|---|
ImmutableMap<K,V> |
build()
Returns a newly-created immutable map.
|
ImmutableMap.Builder<K,V> |
orderEntriesByValue(Comparator<? super V> valueComparator)
Configures this
Builder to order entries by value according to the specified
comparator. |
ImmutableMap.Builder<K,V> |
put(K key,
V value)
Associates
key with value in the built map. |
ImmutableMap.Builder<K,V> |
put(Map.Entry<? extends K,? extends V> entry)
Adds the given
entry to the map, making it immutable if necessary. |
ImmutableMap.Builder<K,V> |
putAll(Iterable<? extends Map.Entry<? extends K,? extends V>> entries)
Adds all of the given entries to the built map.
|
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.
|
public Builder()
ImmutableMap.builder()
.@CanIgnoreReturnValue public ImmutableMap.Builder<K,V> put(K key, V value)
key
with value
in the built map. Duplicate keys are not allowed,
and will cause build()
to fail.@CanIgnoreReturnValue public ImmutableMap.Builder<K,V> put(Map.Entry<? extends K,? extends V> entry)
entry
to the map, making it immutable if necessary. Duplicate keys are
not allowed, and will cause build()
to fail.@CanIgnoreReturnValue public ImmutableMap.Builder<K,V> putAll(Map<? extends K,? extends V> map)
build()
to fail.NullPointerException
- if any key or value in map
is null@CanIgnoreReturnValue @Beta public ImmutableMap.Builder<K,V> putAll(Iterable<? extends Map.Entry<? extends K,? extends V>> entries)
build()
to fail.NullPointerException
- if any key, value, or entry is null@CanIgnoreReturnValue @Beta public ImmutableMap.Builder<K,V> orderEntriesByValue(Comparator<? super V> valueComparator)
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.
IllegalStateException
- if this method was already calledpublic ImmutableMap<K,V> build()
orderEntriesByValue(java.util.Comparator<? super V>)
was
called, in which case entries are sorted by value.IllegalArgumentException
- if duplicate keys were addedCopyright © 2010–2019. All rights reserved.