MultiValueMap (Spring Framework 4.3.30.RELEASE API)

类型参数:
K - the key type
V - the value element type
所有超级接口:
Map<K,List<V>>
所有已知实现类:
HttpHeaders, LinkedMultiValueMap, StompHeaders, WebSocketHttpHeaders
```
public interface MultiValueMap<K,V>
extends Map<K,List<V>>
```
Extension of the Map interface that stores multiple values.
从以下版本开始:
3.0
作者:
Arjen Poutsma

嵌套类概要
- 从接口继承的嵌套类/接口 java.util.Map
  Map.Entry<K extends Object,V extends Object>

方法概要

所有方法实例方法抽象方法
修饰符和类型	方法	说明
`void`	`add(K key, V value)`	Add the given single value to the current list of values for the given key.
`V`	`getFirst(K key)`	Return the first value for the given key.
`void`	`set(K key, V value)`	Set the given single value under the given key.
`void`	`setAll(Map<K,V> values)`	Set the given values under.
`Map<K,V>`	`toSingleValueMap()`	Return a `Map` with the first values contained in this `MultiValueMap`.

从接口继承的方法 java.util.Map
clear, compute, computeIfAbsent, computeIfPresent, containsKey, containsValue, entrySet, equals, forEach, get, getOrDefault, hashCode, isEmpty, keySet, merge, put, putAll, putIfAbsent, remove, remove, replace, replace, replaceAll, size, values

- 方法详细资料
  - getFirst
```
V getFirst(K key)
```
    Return the first value for the given key.
    参数:
    key - the key
    返回:
    the first value for the specified key, or null if none
  - add
```
void add(K key,
         V value)
```
    Add the given single value to the current list of values for the given key.
    参数:
    key - the key
    value - the value to be added
  - set
```
void set(K key,
         V value)
```
    Set the given single value under the given key.
    参数:
    key - the key
    value - the value to set
  - setAll
```
void setAll(Map<K,V> values)
```
    Set the given values under.
    参数:
    values - the values.
  - toSingleValueMap
```
Map<K,V> toSingleValueMap()
```
    Return a Map with the first values contained in this MultiValueMap.
    返回:
    a single value representation of this map