Class ImmutableMultimap<K,V>
- java.lang.Object
-
- com.google.common.collect.ImmutableMultimap<K,V>
-
- All Implemented Interfaces:
Multimap<K,V>
,Serializable
- Direct Known Subclasses:
ImmutableListMultimap
,ImmutableSetMultimap
@GwtCompatible(emulated=true) public abstract class ImmutableMultimap<K,V> extends Object implements Serializable
AMultimap
whose contents will never change, with many other important properties detailed atImmutableCollection
.Warning: avoid direct usage of
ImmutableMultimap
as a type (as withMultimap
itself). Prefer subtypes such asImmutableSetMultimap
orImmutableListMultimap
, which have well-definedMultimap.equals(java.lang.Object)
semantics, thus avoiding a common source of bugs and confusion.Note: every
ImmutableMultimap
offers aninverse()
view, so there is no need for a distinctImmutableBiMultimap
type.Key-grouped iteration. All view collections follow the same iteration order. In all current implementations, the iteration order always keeps multiple entries with the same key together. Any creation method that would customarily respect insertion order (such as
copyOf(Multimap)
) instead preserves key-grouped order by inserting entries for an existing key immediately after the last entry having that key.See the Guava User Guide article on immutable collections.
- Since:
- 2.0
- Author:
- Jared Levy
- See Also:
- Serialized Form
-
-
Nested Class Summary
Nested Classes Modifier and Type Class Description static class
ImmutableMultimap.Builder<K,V>
A builder for creating immutable multimap instances, especiallypublic static final
multimaps ("constant multimaps").
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Method Summary
All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods Modifier and Type Method Description ImmutableMap<K,Collection<V>>
asMap()
Returns an immutable map that associates each key with its corresponding values in the multimap.static <K,V>
ImmutableMultimap.Builder<K,V>builder()
Returns a new builder.void
clear()
Deprecated.Unsupported operation.boolean
containsEntry(Object key, Object value)
Returnstrue
if this multimap contains at least one key-value pair with the keykey
and the valuevalue
.boolean
containsKey(Object key)
Returnstrue
if this multimap contains at least one key-value pair with the keykey
.boolean
containsValue(Object value)
Returnstrue
if this multimap contains at least one key-value pair with the valuevalue
.static <K,V>
ImmutableMultimap<K,V>copyOf(Multimap<? extends K,? extends V> multimap)
Returns an immutable multimap containing the same mappings asmultimap
, in the "key-grouped" iteration order described in the class documentation.static <K,V>
ImmutableMultimap<K,V>copyOf(Iterable<? extends Map.Entry<? extends K,? extends V>> entries)
Returns an immutable multimap containing the specified entries.ImmutableCollection<Map.Entry<K,V>>
entries()
Returns an immutable collection of all key-value pairs in the multimap.boolean
equals(Object object)
Indicates whether some other object is "equal to" this one.abstract ImmutableCollection<V>
get(K key)
Returns an immutable collection of the values for the given key.int
hashCode()
Returns the hash code for this multimap.abstract ImmutableMultimap<V,K>
inverse()
Returns an immutable multimap which is the inverse of this one.boolean
isEmpty()
Returnstrue
if this multimap contains no key-value pairs.ImmutableMultiset<K>
keys()
Returns an immutable multiset containing all the keys in this multimap, in the same order and with the same frequencies as they appear in this multimap; to get only a single occurrence of each key, usekeySet()
.ImmutableSet<K>
keySet()
Returns an immutable set of the distinct keys in this multimap, in the same order as they appear in this multimap.static <K,V>
ImmutableMultimap<K,V>of()
Returns an empty multimap.static <K,V>
ImmutableMultimap<K,V>of(K k1, V v1)
Returns an immutable multimap containing a single entry.static <K,V>
ImmutableMultimap<K,V>of(K k1, V v1, K k2, V v2)
Returns an immutable multimap containing the given entries, in order.static <K,V>
ImmutableMultimap<K,V>of(K k1, V v1, K k2, V v2, K k3, V v3)
Returns an immutable multimap containing the given entries, in the "key-grouped" insertion order described in the class documentation.static <K,V>
ImmutableMultimap<K,V>of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4)
Returns an immutable multimap containing the given entries, in the "key-grouped" insertion order described in the class documentation.static <K,V>
ImmutableMultimap<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 multimap containing the given entries, in the "key-grouped" insertion order described in the class documentation.boolean
put(K key, V value)
Deprecated.Unsupported operation.boolean
putAll(Multimap<? extends K,? extends V> multimap)
Deprecated.Unsupported operation.boolean
putAll(K key, Iterable<? extends V> values)
Deprecated.Unsupported operation.boolean
remove(Object key, Object value)
Deprecated.Unsupported operation.ImmutableCollection<V>
removeAll(Object key)
Deprecated.Unsupported operation.ImmutableCollection<V>
replaceValues(K key, Iterable<? extends V> values)
Deprecated.Unsupported operation.int
size()
Returns the number of key-value pairs in this multimap.String
toString()
Returns a string representation of the multimap, generated by callingtoString
on the map returned byMultimap.asMap()
.ImmutableCollection<V>
values()
Returns an immutable collection of the values in this multimap.
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-
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Method Detail
-
of
public static <K,V> ImmutableMultimap<K,V> of()
Returns an empty multimap.Performance note: the instance returned is a singleton.
-
of
public static <K,V> ImmutableMultimap<K,V> of(K k1, V v1)
Returns an immutable multimap containing a single entry.
-
of
public static <K,V> ImmutableMultimap<K,V> of(K k1, V v1, K k2, V v2)
Returns an immutable multimap containing the given entries, in order.
-
of
public static <K,V> ImmutableMultimap<K,V> of(K k1, V v1, K k2, V v2, K k3, V v3)
Returns an immutable multimap containing the given entries, in the "key-grouped" insertion order described in the class documentation.
-
of
public static <K,V> ImmutableMultimap<K,V> of(K k1, V v1, K k2, V v2, K k3, V v3, K k4, V v4)
Returns an immutable multimap containing the given entries, in the "key-grouped" insertion order described in the class documentation.
-
of
public static <K,V> ImmutableMultimap<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 multimap containing the given entries, in the "key-grouped" insertion order described in the class documentation.
-
builder
public static <K,V> ImmutableMultimap.Builder<K,V> builder()
Returns a new builder. The generated builder is equivalent to the builder created by theImmutableMultimap.Builder
constructor.
-
copyOf
public static <K,V> ImmutableMultimap<K,V> copyOf(Multimap<? extends K,? extends V> multimap)
Returns an immutable multimap containing the same mappings asmultimap
, in the "key-grouped" iteration order described in the class documentation.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 inmultimap
is null
-
copyOf
@Beta public static <K,V> ImmutableMultimap<K,V> copyOf(Iterable<? extends Map.Entry<? extends K,? extends V>> entries)
Returns an immutable multimap containing the specified entries. The returned multimap iterates over keys in the order they were first encountered in the input, and the values for each key are iterated in the order they were encountered.- Throws:
NullPointerException
- if any key, value, or entry is null- Since:
- 19.0
-
removeAll
@CanIgnoreReturnValue @Deprecated public ImmutableCollection<V> removeAll(@CheckForNull Object key)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the multimap unmodified.- Specified by:
removeAll
in interfaceMultimap<K,V>
- Returns:
- the values that were removed (possibly empty). The returned collection may be modifiable, but updating it will have no effect on the multimap.
- Throws:
UnsupportedOperationException
- always
-
replaceValues
@CanIgnoreReturnValue @Deprecated public ImmutableCollection<V> replaceValues(K key, Iterable<? extends V> values)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the multimap unmodified.- Specified by:
replaceValues
in interfaceMultimap<K,V>
- Returns:
- the collection of replaced values, or an empty collection if no values were previously associated with the key. The collection may be modifiable, but updating it will have no effect on the multimap.
- Throws:
UnsupportedOperationException
- always
-
clear
@Deprecated public final void clear()
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the multimap unmodified.- Specified by:
clear
in interfaceMultimap<K,V>
- Throws:
UnsupportedOperationException
- always
-
get
public abstract ImmutableCollection<V> get(K key)
Returns an immutable collection of the values for the given key. If no mappings in the multimap have the provided key, an empty immutable collection is returned. The values are in the same order as the parameters used to build this multimap.
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inverse
public abstract ImmutableMultimap<V,K> inverse()
Returns an immutable multimap which is the inverse of this one. For every key-value mapping in the original, the result will have a mapping with key and value reversed.- Since:
- 11.0
-
put
@CanIgnoreReturnValue @Deprecated public final boolean put(K key, V value)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the multimap unmodified.- Specified by:
put
in interfaceMultimap<K,V>
- Returns:
true
if the method increased the size of the multimap, orfalse
if the multimap already contained the key-value pair and doesn't allow duplicates- Throws:
UnsupportedOperationException
- always
-
putAll
@CanIgnoreReturnValue @Deprecated public final boolean putAll(K key, Iterable<? extends V> values)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the multimap unmodified.- Specified by:
putAll
in interfaceMultimap<K,V>
- Returns:
true
if the multimap changed- Throws:
UnsupportedOperationException
- always
-
putAll
@CanIgnoreReturnValue @Deprecated public final boolean putAll(Multimap<? extends K,? extends V> multimap)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the multimap unmodified.- Specified by:
putAll
in interfaceMultimap<K,V>
- Returns:
true
if the multimap changed- Throws:
UnsupportedOperationException
- always
-
remove
@CanIgnoreReturnValue @Deprecated public final boolean remove(@CheckForNull Object key, @CheckForNull Object value)
Deprecated.Unsupported operation.Guaranteed to throw an exception and leave the multimap unmodified.- Specified by:
remove
in interfaceMultimap<K,V>
- Returns:
true
if the multimap changed- Throws:
UnsupportedOperationException
- always
-
containsKey
public boolean containsKey(@CheckForNull Object key)
Description copied from interface:Multimap
Returnstrue
if this multimap contains at least one key-value pair with the keykey
.- Specified by:
containsKey
in interfaceMultimap<K,V>
-
containsValue
public boolean containsValue(@CheckForNull Object value)
Description copied from interface:Multimap
Returnstrue
if this multimap contains at least one key-value pair with the valuevalue
.- Specified by:
containsValue
in interfaceMultimap<K,V>
-
size
public int size()
Description copied from interface:Multimap
Returns the number of key-value pairs in this multimap.Note: this method does not return the number of distinct keys in the multimap, which is given by
keySet().size()
orasMap().size()
. See the opening section of theMultimap
class documentation for clarification.
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keySet
public ImmutableSet<K> keySet()
Returns an immutable set of the distinct keys in this multimap, in the same order as they appear in this multimap.
-
asMap
public ImmutableMap<K,Collection<V>> asMap()
Returns an immutable map that associates each key with its corresponding values in the multimap. Keys and values appear in the same order as in this multimap.
-
entries
public ImmutableCollection<Map.Entry<K,V>> entries()
Returns an immutable collection of all key-value pairs in the multimap.
-
keys
public ImmutableMultiset<K> keys()
Returns an immutable multiset containing all the keys in this multimap, in the same order and with the same frequencies as they appear in this multimap; to get only a single occurrence of each key, usekeySet()
.
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values
public ImmutableCollection<V> values()
Returns an immutable collection of the values in this multimap. Its iterator traverses the values for the first key, the values for the second key, and so on.
-
isEmpty
public boolean isEmpty()
Description copied from interface:Multimap
Returnstrue
if this multimap contains no key-value pairs. Equivalent tosize() == 0
, but can in some cases be more efficient.
-
containsEntry
public boolean containsEntry(@CheckForNull Object key, @CheckForNull Object value)
Description copied from interface:Multimap
Returnstrue
if this multimap contains at least one key-value pair with the keykey
and the valuevalue
.
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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.- Specified by:
equals
in interfaceMultimap<K extends @Nullable Object,V extends @Nullable Object>
- Overrides:
equals
in classObject
- Parameters:
object
- the reference object with which to compare.- Returns:
true
if this object is the same as the obj argument;false
otherwise.- See Also:
Object.hashCode()
,HashMap
- It is reflexive: for any non-null reference value
-
hashCode
public int hashCode()
Returns the hash code for this multimap.The hash code of a multimap is defined as the hash code of the map view, as returned by
Multimap.asMap()
.
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toString
public String toString()
Returns a string representation of the multimap, generated by callingtoString
on the map returned byMultimap.asMap()
.
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