Type Parameters:

K - The type of key objects

V - The type of value objects

All Superinterfaces:

Map<K,V>

All Known Subinterfaces:

Form
```
public interface MultiValueMap<K,V>
extends Map<K,V>
```
A map that may contain multiple values for a given key, but typically only one value.
Unlike other multi map types, this type is optimized for the case where there is only one value for a key. The map acts just like a normal Map, but has extra methods for getting all values for a key.
All implementations of this type are immutable. Mutating operations throw UnsupportedOperationException.
Where there is multiple values for a given key, retrieving a single value will return the first value, where the first value is intrinsic to the service in which the map is being used.

Nested Class Summary
- Nested classes/interfaces inherited from interface java.util.Map
  Map.Entry<K extends Object,V extends Object>

Method Summary

All Methods Static Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`com.google.common.collect.ListMultimap<K,V>`	`asMultimap()`
`void`	`clear()`	Throws `UnsupportedOperationException`.
`static <K,V> MultiValueMap<K,V>`	`empty()`
`V`	`get(Object key)`	Get the first value for the key, or `null` if there are no values for the key.
`Map<K,List<V>>`	`getAll()`	Returns a new view of the map where each map value is a list of all the values for the given key (i.e.
`List<V>`	`getAll(K key)`	All of the values for the given key.
`V`	`put(K key, V value)`	Throws `UnsupportedOperationException`.
`void`	`putAll(Map<? extends K,? extends V> m)`	Throws `UnsupportedOperationException`.
`V`	`remove(Object key)`	Throws `UnsupportedOperationException`.

Methods inherited from interface java.util.Map
compute, computeIfAbsent, computeIfPresent, containsKey, containsValue, entrySet, equals, forEach, getOrDefault, hashCode, isEmpty, keySet, merge, putIfAbsent, remove, replace, replace, replaceAll, size, values

- Method Detail
  - empty
```
static <K,V> MultiValueMap<K,V> empty()
```
  - getAll
```
List<V> getAll(K key)
```
    All of the values for the given key. An empty list if there are no values for the key.
    The returned list is immutable.
    
    Parameters:
    
    key - The key to return all values of
    
    Returns:
    
    all of the values for the given key, or an empty list if there are no values for the key.
  - getAll
```
Map<K,List<V>> getAll()
```
    Returns a new view of the map where each map value is a list of all the values for the given key (i.e. a traditional multi map).
    The returned map is immutable.
    
    Returns:
    
    A new view of the map where each map value is a list of all the values for the given key
  - get
```
@Nullable
V get(Object key)
```
    Get the first value for the key, or null if there are no values for the key.
    
    Specified by:
    
    get in interface Map<K,V>
    
    Parameters:
    
    key - The key to obtain the first value for
    
    Returns:
    
    The first value for the given key, or null if there are no values for the given key
  - put
```
V put(K key,
      V value)
```
    Throws UnsupportedOperationException.
    
    Specified by:
    
    put in interface Map<K,V>
  - remove
```
V remove(Object key)
```
    Throws UnsupportedOperationException.
    
    Specified by:
    
    remove in interface Map<K,V>
  - putAll
```
void putAll(Map<? extends K,? extends V> m)
```
    Throws UnsupportedOperationException.
    
    Specified by:
    
    putAll in interface Map<K,V>
  - clear
```
void clear()
```
    Throws UnsupportedOperationException.
    
    Specified by:
    
    clear in interface Map<K,V>
  - asMultimap
```
com.google.common.collect.ListMultimap<K,V> asMultimap()
```

Interface MultiValueMap<K,​V>

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Method Summary

Methods inherited from interface java.util.Map

Method Detail

empty

getAll

getAll

get

put

remove

putAll

clear

asMultimap

Interface MultiValueMap<K,V>