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
@DoNotMock("Use ImmutableMap.of or another implementation") @GwtCompatible(serializable=true, emulated=true) public abstract class ImmutableMap<K,V> extends Object implements Map<K,V>, Serializable
AMap
whose contents will never change, with many other important properties detailed atImmutableCollection
.See the Guava User Guide article on immutable collections.
- Since:
- 2.0
- Author:
- Jesse Wilson, Kevin Bourrillion
- See Also:
- Serialized Form
-
-
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.static <K,V>
ImmutableMap.Builder<K,V>builderWithExpectedSize(int expectedSize)
Returns a new builder, expecting the specified number of entries to be added.void
clear()
Deprecated.Unsupported operation.V
compute(K key, BiFunction<? super K,? super @Nullable V,? extends V> remappingFunction)
Deprecated.Unsupported operation.V
computeIfAbsent(K key, Function<? super K,? extends V> mappingFunction)
Deprecated.Unsupported operation.V
computeIfPresent(K key, BiFunction<? super K,? super V,? extends V> remappingFunction)
Deprecated.Unsupported operation.boolean
containsKey(Object key)
Returnstrue
if this map contains a mapping for the specified key.boolean
containsValue(Object value)
Returnstrue
if this map maps one or more keys to the specified value.static <K,V>
ImmutableMap<K,V>copyOf(Iterable<? extends Map.Entry<? extends K,? extends V>> entries)
Returns an immutable map containing the specified entries.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)
Indicates whether some other object is "equal to" this one.abstract V
get(Object key)
Returns the value to which the specified key is mapped, ornull
if this map contains no mapping for the key.V
getOrDefault(Object key, V defaultValue)
Returns the value to which the specified key is mapped, ordefaultValue
if this map contains no mapping for the key.int
hashCode()
Returns a hash code value for the object.boolean
isEmpty()
Returnstrue
if this map contains no key-value mappings.ImmutableSet<K>
keySet()
Returns an immutable set of the keys in this map, in the same order that they appear inentrySet
.V
merge(K key, V value, BiFunction<? super V,? super V,? extends V> remappingFunction)
Deprecated.Unsupported operation.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.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.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.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.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.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.static <K,V>
ImmutableMap<K,V>ofEntries(Map.Entry<? extends K,? extends V>... entries)
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
putIfAbsent(K key, V value)
Deprecated.Unsupported operation.V
remove(Object o)
Deprecated.Unsupported operation.boolean
remove(Object key, Object value)
Deprecated.Unsupported operation.V
replace(K key, V value)
Deprecated.Unsupported operation.boolean
replace(K key, V oldValue, V newValue)
Deprecated.Unsupported operation.void
replaceAll(BiFunction<? super K,? super V,? extends V> function)
Deprecated.Unsupported operation.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 aCollector
that accumulates elements into anImmutableMap
whose keys and values are the result of applying the provided mapping functions to the input elements.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 aCollector
that accumulates elements into anImmutableMap
whose keys and values are the result of applying the provided mapping functions to the input elements.String
toString()
Returns a string representation of the object.ImmutableCollection<V>
values()
Returns an immutable collection of the values in this map, in the same order that they appear inentrySet
.
-
-
-
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 aCollector
that accumulates elements into anImmutableMap
whose keys and values are the result of applying the provided mapping functions to the input elements. Entries appear in the resultImmutableMap
in encounter order.If the mapped keys contain duplicates (according to
Object.equals(Object)
, anIllegalArgumentException
is thrown when the collection operation is performed. (This differs from theCollector
returned byCollectors.toMap(Function, Function)
, which throws anIllegalStateException
.)- Since:
- 21.0
-
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 aCollector
that accumulates elements into anImmutableMap
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. Entries will appear in the encounter order of the first occurrence of the key.- Since:
- 21.0
-
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.Performance note: the instance returned is a singleton.
- Type Parameters:
K
- theMap
's key typeV
- theMap
's value type- Returns:
- an empty
Map
-
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.- Type Parameters:
K
- theMap
's key typeV
- theMap
's value type- Parameters:
k1
- the mapping's keyv1
- the mapping's value- Returns:
- a
Map
containing the specified mapping
-
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.- Type Parameters:
K
- theMap
's key typeV
- theMap
's value type- Parameters:
k1
- the first mapping's keyv1
- the first mapping's valuek2
- the second mapping's keyv2
- the second mapping's value- Returns:
- a
Map
containing the specified mappings - 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.- Type Parameters:
K
- theMap
's key typeV
- theMap
's value type- Parameters:
k1
- the first mapping's keyv1
- the first mapping's valuek2
- the second mapping's keyv2
- the second mapping's valuek3
- the third mapping's keyv3
- the third mapping's value- Returns:
- a
Map
containing the specified mappings - 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.- Type Parameters:
K
- theMap
's key typeV
- theMap
's value type- Parameters:
k1
- the first mapping's keyv1
- the first mapping's valuek2
- the second mapping's keyv2
- the second mapping's valuek3
- the third mapping's keyv3
- the third mapping's valuek4
- the fourth mapping's keyv4
- the fourth mapping's value- Returns:
- a
Map
containing the specified mappings - 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.- Type Parameters:
K
- theMap
's key typeV
- theMap
's value type- Parameters:
k1
- the first mapping's keyv1
- the first mapping's valuek2
- the second mapping's keyv2
- the second mapping's valuek3
- the third mapping's keyv3
- the third mapping's valuek4
- the fourth mapping's keyv4
- the fourth mapping's valuek5
- the fifth mapping's keyv5
- the fifth mapping's value- Returns:
- a
Map
containing the specified mappings - 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.- Type Parameters:
K
- theMap
's key typeV
- theMap
's value type- Parameters:
k1
- the first mapping's keyv1
- the first mapping's valuek2
- the second mapping's keyv2
- the second mapping's valuek3
- the third mapping's keyv3
- the third mapping's valuek4
- the fourth mapping's keyv4
- the fourth mapping's valuek5
- the fifth mapping's keyv5
- the fifth mapping's valuek6
- the sixth mapping's keyv6
- the sixth mapping's value- Returns:
- a
Map
containing the specified mappings - 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.- Type Parameters:
K
- theMap
's key typeV
- theMap
's value type- Parameters:
k1
- the first mapping's keyv1
- the first mapping's valuek2
- the second mapping's keyv2
- the second mapping's valuek3
- the third mapping's keyv3
- the third mapping's valuek4
- the fourth mapping's keyv4
- the fourth mapping's valuek5
- the fifth mapping's keyv5
- the fifth mapping's valuek6
- the sixth mapping's keyv6
- the sixth mapping's valuek7
- the seventh mapping's keyv7
- the seventh mapping's value- Returns:
- a
Map
containing the specified mappings - 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.- Type Parameters:
K
- theMap
's key typeV
- theMap
's value type- Parameters:
k1
- the first mapping's keyv1
- the first mapping's valuek2
- the second mapping's keyv2
- the second mapping's valuek3
- the third mapping's keyv3
- the third mapping's valuek4
- the fourth mapping's keyv4
- the fourth mapping's valuek5
- the fifth mapping's keyv5
- the fifth mapping's valuek6
- the sixth mapping's keyv6
- the sixth mapping's valuek7
- the seventh mapping's keyv7
- the seventh mapping's valuek8
- the eighth mapping's keyv8
- the eighth mapping's value- Returns:
- a
Map
containing the specified mappings - 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.- Type Parameters:
K
- theMap
's key typeV
- theMap
's value type- Parameters:
k1
- the first mapping's keyv1
- the first mapping's valuek2
- the second mapping's keyv2
- the second mapping's valuek3
- the third mapping's keyv3
- the third mapping's valuek4
- the fourth mapping's keyv4
- the fourth mapping's valuek5
- the fifth mapping's keyv5
- the fifth mapping's valuek6
- the sixth mapping's keyv6
- the sixth mapping's valuek7
- the seventh mapping's keyv7
- the seventh mapping's valuek8
- the eighth mapping's keyv8
- the eighth mapping's valuek9
- the ninth mapping's keyv9
- the ninth mapping's value- Returns:
- a
Map
containing the specified mappings - 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.- Type Parameters:
K
- theMap
's key typeV
- theMap
's value type- Parameters:
k1
- the first mapping's keyv1
- the first mapping's valuek2
- the second mapping's keyv2
- the second mapping's valuek3
- the third mapping's keyv3
- the third mapping's valuek4
- the fourth mapping's keyv4
- the fourth mapping's valuek5
- the fifth mapping's keyv5
- the fifth mapping's valuek6
- the sixth mapping's keyv6
- the sixth mapping's valuek7
- the seventh mapping's keyv7
- the seventh mapping's valuek8
- the eighth mapping's keyv8
- the eighth mapping's valuek9
- the ninth mapping's keyv9
- the ninth mapping's valuek10
- the tenth mapping's keyv10
- the tenth mapping's value- Returns:
- a
Map
containing the specified mappings - Throws:
IllegalArgumentException
- if duplicate keys are provided- Since:
- 31.0
-
ofEntries
@SafeVarargs public static <K,V> ImmutableMap<K,V> ofEntries(Map.Entry<? extends K,? extends V>... entries)
Returns an immutable map containing the given entries, in order.- Type Parameters:
K
- theMap
's key typeV
- theMap
's value type- Parameters:
entries
-Map.Entry
s containing the keys and values from which the map is populated- Returns:
- a
Map
containing the specified mappings - Throws:
IllegalArgumentException
- if duplicate keys are provided- Since:
- 31.0
- See Also:
Map.entry()
-
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.
-
builderWithExpectedSize
@Beta 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 beforeImmutableMap.Builder.build(boolean)
is called, the builder is likely to perform better than an unsizedbuilder()
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 asmap
. The returned map iterates over entries in the same order as theentrySet
of the original map. 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.
- Type Parameters:
K
- theMap
's key typeV
- theMap
's value type- Parameters:
map
- aMap
from which entries are drawn, must be non-null- Returns:
- a
Map
containing the entries of the givenMap
- Throws:
NullPointerException
- if any key or value inmap
is null
-
copyOf
@Beta 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 nullIllegalArgumentException
- if two entries have the same key- Since:
- 19.0
-
put
@CanIgnoreReturnValue @Deprecated @CheckForNull 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>
- Parameters:
k
- key with which the specified value is to be associatedv
- value to be associated with the specified key- Returns:
- the previous value associated with
key
, ornull
if there was no mapping forkey
. (Anull
return can also indicate that the map previously associatednull
withkey
, if the implementation supportsnull
values.) - Throws:
UnsupportedOperationException
- always
-
putIfAbsent
@CanIgnoreReturnValue @Deprecated @CheckForNull public final V putIfAbsent(K key, V value)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the map unmodified.- Specified by:
putIfAbsent
in interfaceMap<K,V>
- Parameters:
key
- key with which the specified value is to be associatedvalue
- value to be associated with the specified key- Returns:
- the previous value associated with the specified key, or
null
if there was no mapping for the key. (Anull
return can also indicate that the map previously associatednull
with the key, if the implementation supports null values.) - Throws:
UnsupportedOperationException
- always
-
replace
@Deprecated public final boolean replace(K key, V oldValue, V newValue)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the map unmodified.- Specified by:
replace
in interfaceMap<K,V>
- Parameters:
key
- key with which the specified value is associatedoldValue
- value expected to be associated with the specified keynewValue
- value to be associated with the specified key- Returns:
true
if the value was replaced- Throws:
UnsupportedOperationException
- always
-
replace
@Deprecated @CheckForNull public final V replace(K key, V value)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the map unmodified.- Specified by:
replace
in interfaceMap<K,V>
- Parameters:
key
- key with which the specified value is associatedvalue
- value to be associated with the specified key- Returns:
- the previous value associated with the specified key, or
null
if there was no mapping for the key. (Anull
return can also indicate that the map previously associatednull
with the key, if the implementation supports null values.) - Throws:
UnsupportedOperationException
- always
-
computeIfAbsent
@Deprecated public final V computeIfAbsent(K key, Function<? super K,? extends V> mappingFunction)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the map unmodified.- Specified by:
computeIfAbsent
in interfaceMap<K,V>
- Parameters:
key
- key with which the specified value is to be associatedmappingFunction
- the mapping function to compute a value- Returns:
- the current (existing or computed) value associated with the specified key, or null if the computed value is null
- Throws:
UnsupportedOperationException
- always
-
computeIfPresent
@Deprecated public final V computeIfPresent(K key, BiFunction<? super K,? super V,? extends V> remappingFunction)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the map unmodified.- Specified by:
computeIfPresent
in interfaceMap<K,V>
- Parameters:
key
- key with which the specified value is to be associatedremappingFunction
- the remapping function to compute a value- Returns:
- the new value associated with the specified key, or null if none
- Throws:
UnsupportedOperationException
- always
-
compute
@Deprecated public final V compute(K key, BiFunction<? super K,? super @Nullable V,? extends V> remappingFunction)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the map unmodified.- Specified by:
compute
in interfaceMap<K,V>
- Parameters:
key
- key with which the specified value is to be associatedremappingFunction
- the remapping function to compute a value- Returns:
- the new value associated with the specified key, or null if none
- Throws:
UnsupportedOperationException
- always
-
merge
@Deprecated public final V merge(K key, V value, BiFunction<? super V,? super V,? extends V> remappingFunction)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the map unmodified.- Specified by:
merge
in interfaceMap<K,V>
- Parameters:
key
- key with which the resulting value is to be associatedvalue
- the non-null value to be merged with the existing value associated with the key or, if no existing value or a null value is associated with the key, to be associated with the keyremappingFunction
- the remapping function to recompute a value if present- Returns:
- the new value associated with the specified key, or null if no value is associated with the key
- 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>
- Parameters:
map
- mappings to be stored in this map- Throws:
UnsupportedOperationException
- always
-
replaceAll
@Deprecated public final void replaceAll(BiFunction<? super K,? super V,? extends V> function)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the map unmodified.- Specified by:
replaceAll
in interfaceMap<K,V>
- Parameters:
function
- the function to apply to each entry- Throws:
UnsupportedOperationException
- always
-
remove
@Deprecated @CheckForNull public final V remove(@CheckForNull Object o)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the map unmodified.- Specified by:
remove
in interfaceMap<K,V>
- Parameters:
o
- key whose mapping is to be removed from the map- Returns:
- the previous value associated with
key
, ornull
if there was no mapping forkey
. - Throws:
UnsupportedOperationException
- always
-
remove
@Deprecated public final boolean remove(@CheckForNull Object key, @CheckForNull Object value)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the map unmodified.- Specified by:
remove
in interfaceMap<K,V>
- Parameters:
key
- key with which the specified value is associatedvalue
- value expected to be associated with the specified key- Returns:
true
if the value was removed- 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
-
isEmpty
public boolean isEmpty()
Description copied from interface:java.util.Map
Returnstrue
if this map contains no key-value mappings.
-
containsKey
public boolean containsKey(@CheckForNull Object key)
Description copied from interface:java.util.Map
Returnstrue
if this map contains a mapping for the specified key. More formally, returnstrue
if and only if this map contains a mapping for a keyk
such thatObjects.equals(key, k)
. (There can be at most one such mapping.)- Specified by:
containsKey
in interfaceMap<K,V>
- Parameters:
key
- key whose presence in this map is to be tested- Returns:
true
if this map contains a mapping for the specified key
-
containsValue
public boolean containsValue(@CheckForNull Object value)
Description copied from interface:java.util.Map
Returnstrue
if this map maps one or more keys to the specified value. More formally, returnstrue
if and only if this map contains at least one mapping to a valuev
such thatObjects.equals(value, v)
. This operation will probably require time linear in the map size for most implementations of theMap
interface.- Specified by:
containsValue
in interfaceMap<K,V>
- Parameters:
value
- value whose presence in this map is to be tested- Returns:
true
if this map maps one or more keys to the specified value
-
get
@CheckForNull public abstract V get(@CheckForNull Object key)
Description copied from interface:java.util.Map
Returns the value to which the specified key is mapped, ornull
if this map contains no mapping for the key.More formally, if this map contains a mapping from a key
k
to a valuev
such thatObjects.equals(key, k)
, then this method returnsv
; otherwise it returnsnull
. (There can be at most one such mapping.)If this map permits null values, then a return value of
null
does not necessarily indicate that the map contains no mapping for the key; it's also possible that the map explicitly maps the key tonull
. ThecontainsKey
operation may be used to distinguish these two cases.
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getOrDefault
@CheckForNull public final V getOrDefault(@CheckForNull Object key, @CheckForNull V defaultValue)
Description copied from interface:java.util.Map
Returns the value to which the specified key is mapped, ordefaultValue
if this map contains no mapping for the key.- Specified by:
getOrDefault
in interfaceMap<K,V>
- Parameters:
key
- the key whose associated value is to be returneddefaultValue
- the default mapping of the key- Returns:
- the value to which the specified key is mapped, or
defaultValue
if this map contains no mapping for the key - Since:
- 21.0 (but only since 23.5 in the Android flavor). Note, however, that Java 8 users can call this method with any version and flavor of Guava.
-
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.
-
keySet
public ImmutableSet<K> keySet()
Returns an immutable set of the keys in this map, in the same order that they appear inentrySet
.
-
values
public ImmutableCollection<V> values()
Returns an immutable collection of the values in this map, in the same order that they appear inentrySet
.
-
asMultimap
public ImmutableSetMultimap<K,V> asMultimap()
Returns a multimap view of the map.- Since:
- 14.0
-
equals
public boolean equals(@CheckForNull Object object)
Description copied from class:java.lang.Object
Indicates whether some other object is "equal to" this one.The
equals
method implements an equivalence relation on non-null object references:- It is reflexive: for any non-null reference value
x
,x.equals(x)
should returntrue
. - It is symmetric: for any non-null reference values
x
andy
,x.equals(y)
should returntrue
if and only ify.equals(x)
returnstrue
. - It is transitive: for any non-null reference values
x
,y
, andz
, ifx.equals(y)
returnstrue
andy.equals(z)
returnstrue
, thenx.equals(z)
should returntrue
. - It is consistent: for any non-null reference values
x
andy
, multiple invocations ofx.equals(y)
consistently returntrue
or consistently returnfalse
, provided no information used inequals
comparisons on the objects is modified. - For any non-null reference value
x
,x.equals(null)
should returnfalse
.
The
equals
method for classObject
implements the most discriminating possible equivalence relation on objects; that is, for any non-null reference valuesx
andy
, this method returnstrue
if and only ifx
andy
refer to the same object (x == y
has the valuetrue
).Note that it is generally necessary to override the
hashCode
method whenever this method is overridden, so as to maintain the general contract for thehashCode
method, which states that equal objects must have equal hash codes. - It is reflexive: for any non-null reference value
-
hashCode
public int hashCode()
Description copied from class:java.lang.Object
Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided byHashMap
.The general contract of
hashCode
is:- Whenever it is invoked on the same object more than once during
an execution of a Java application, the
hashCode
method must consistently return the same integer, provided no information used inequals
comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. - If two objects are equal according to the
equals(Object)
method, then calling thehashCode
method on each of the two objects must produce the same integer result. - It is not required that if two objects are unequal
according to the
Object.equals(java.lang.Object)
method, then calling thehashCode
method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.
As much as is reasonably practical, the hashCode method defined by class
Object
does return distinct integers for distinct objects. (The hashCode may or may not be implemented as some function of an object's memory address at some point in time.)- Specified by:
hashCode
in interfaceMap<K,V>
- Overrides:
hashCode
in classObject
- Returns:
- a hash code value for this object.
- See Also:
Object.equals(java.lang.Object)
,System.identityHashCode(java.lang.Object)
- Whenever it is invoked on the same object more than once during
an execution of a Java application, the
-
toString
public String toString()
Description copied from class:java.lang.Object
Returns a string representation of the object. In general, thetoString
method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.The
toString
method for classObject
returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@
', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:getClass().getName() + '@' + Integer.toHexString(hashCode())
-
-