Class ImmutableMap<K,V>
- java.lang.Object
-
- com.google.common.collect.ImmutableMap<K,V>
-
- All Implemented Interfaces:
Serializable
,Map<K,V>
- Direct Known Subclasses:
ImmutableBiMap
,ImmutableSortedMap
@GwtCompatible(serializable=true, emulated=true) public abstract class ImmutableMap<K,V> extends Object implements Map<K,V>, Serializable
An immutable, hash-basedMap
with reliable user-specified iteration order. Does not permit null keys or values.Unlike
Collections.unmodifiableMap(java.util.Map<? extends K, ? extends V>)
, which is a view of a separate map which can still change, an instance ofImmutableMap
contains its own data and will never change.ImmutableMap
is convenient forpublic static final
maps ("constant maps") and also lets you easily make a "defensive copy" of a map provided to your class by a caller.Performance notes: unlike
HashMap
,ImmutableMap
is not optimized for element types that have slowObject.equals(java.lang.Object)
orObject.hashCode()
implementations. You can get better performance by having your element type cache its own hash codes, and by making use of the cached values to short-circuit a slowequals
algorithm.See the Guava User Guide article on immutable collections.
- Since:
- 2.0 (imported from Google Collections Library)
- See Also:
- Serialized Form
-
-
Nested Class Summary
Nested Classes Modifier and Type Class Description static class
ImmutableMap.Builder<K,V>
A builder for creating immutable map instances, especiallypublic static final
maps ("constant maps").
-
Method Summary
All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods Modifier and Type Method Description ImmutableSetMultimap<K,V>
asMultimap()
Returns a multimap view of the map.static <K,V>
ImmutableMap.Builder<K,V>builder()
Returns a new builder.void
clear()
Deprecated.Unsupported operation.boolean
containsKey(Object key)
boolean
containsValue(Object value)
static <K,V>
ImmutableMap<K,V>copyOf(Map<? extends K,? extends V> map)
Returns an immutable map containing the same entries asmap
.ImmutableSet<Map.Entry<K,V>>
entrySet()
Returns an immutable set of the mappings in this map.boolean
equals(Object object)
abstract V
get(Object key)
int
hashCode()
boolean
isEmpty()
ImmutableSet<K>
keySet()
Returns an immutable set of the keys in this map.static <K,V>
ImmutableMap<K,V>of()
Returns the empty map.static <K,V>
ImmutableMap<K,V>of(K k1, V v1)
Returns an immutable map containing a single entry.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.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.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.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.V
put(K k, V v)
Deprecated.Unsupported operation.void
putAll(Map<? extends K,? extends V> map)
Deprecated.Unsupported operation.V
remove(Object o)
Deprecated.Unsupported operation.String
toString()
ImmutableCollection<V>
values()
Returns an immutable collection of the values in this map.-
Methods inherited from interface java.util.Map
compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll, size
-
-
-
-
Method Detail
-
of
public static <K,V> ImmutableMap<K,V> of()
Returns the empty map. This map behaves and performs comparably toCollections.emptyMap()
, and is preferable mainly for consistency and maintainability of your code.
-
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 toCollections.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
-
builder
public static <K,V> ImmutableMap.Builder<K,V> builder()
Returns a new builder. The generated builder is equivalent to the builder created by theImmutableMap.Builder
constructor.
-
copyOf
public static <K,V> ImmutableMap<K,V> copyOf(Map<? extends K,? extends V> map)
Returns an immutable map containing the same entries asmap
. Ifmap
somehow contains entries with duplicate keys (for example, if it is aSortedMap
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 inmap
is null
-
put
@Deprecated public final V put(K k, V v)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the map unmodified.- Specified by:
put
in interfaceMap<K,V>
- Throws:
UnsupportedOperationException
- always
-
remove
@Deprecated public final V remove(Object o)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the map unmodified.- Specified by:
remove
in interfaceMap<K,V>
- Throws:
UnsupportedOperationException
- always
-
putAll
@Deprecated public final void putAll(Map<? extends K,? extends V> map)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the map unmodified.- Specified by:
putAll
in interfaceMap<K,V>
- Throws:
UnsupportedOperationException
- always
-
clear
@Deprecated public final void clear()
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the map unmodified.- Specified by:
clear
in interfaceMap<K,V>
- Throws:
UnsupportedOperationException
- always
-
containsKey
public boolean containsKey(@Nullable Object key)
- Specified by:
containsKey
in interfaceMap<K,V>
-
containsValue
public boolean containsValue(@Nullable Object value)
- Specified by:
containsValue
in interfaceMap<K,V>
-
entrySet
public ImmutableSet<Map.Entry<K,V>> entrySet()
Returns an immutable set of the mappings in this map. The entries are in the same order as the parameters used to build this map.
-
keySet
public ImmutableSet<K> keySet()
Returns an immutable set of the keys in this map. These keys are in the same order as the parameters used to build this map.
-
values
public ImmutableCollection<V> values()
Returns an immutable collection of the values in this map. The values are in the same order as the parameters used to build this map.
-
asMultimap
@Beta public ImmutableSetMultimap<K,V> asMultimap()
Returns a multimap view of the map.- Since:
- 14.0
-
hashCode
public int hashCode()
-
-