org.springframework.util

## Class LinkedMultiValueMap<K,V>

- java.lang.Object
- - org.springframework.util.LinkedMultiValueMap<K,V>

- All Implemented Interfaces:
    Serializable, Map<K,List<V>>, MultiValueMap<K,V>

      public class LinkedMultiValueMap<K,V>
      extends Object
      implements MultiValueMap<K,V>, Serializable

  Simple implementation of `MultiValueMap` that wraps a `LinkedHashMap`, storing multiple values in a `LinkedList`.

  This Map implementation is generally not thread-safe. It is primarily designed for data structures exposed from request objects, for use in a single thread only.

  Since:
    3.0
  Author:
    Arjen Poutsma, Juergen Hoeller
  See Also:
    Serialized Form

- - ### Nested Class Summary

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

      `Map.Entry<K,V>`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `LinkedMultiValueMap()` Create a new LinkedMultiValueMap that wraps a `LinkedHashMap`.
    `LinkedMultiValueMap(int initialCapacity)` Create a new LinkedMultiValueMap that wraps a `LinkedHashMap` with the given initial capacity.
    `LinkedMultiValueMap(Map<K,List<V>> otherMap)` Copy constructor: Create a new LinkedMultiValueMap with the same mappings as the specified Map.

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `add(K key, V value)` Add the given single value to the current list of values for the given key.
    `void` | `clear()`
    `boolean` | `containsKey(Object key)`
    `boolean` | `containsValue(Object value)`
    `Set<Map.Entry<K,List<V>>>` | `entrySet()`
    `boolean` | `equals(Object obj)`
    `List<V>` | `get(Object key)`
    `V` | `getFirst(K key)` Return the first value for the given key.
    `int` | `hashCode()`
    `boolean` | `isEmpty()`
    `Set<K>` | `keySet()`
    `List<V>` | `put(K key, List<V> value)`
    `void` | `putAll(Map<? extends K,? extends List<V>> m)`
    `List<V>` | `remove(Object 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.
    `int` | `size()`
    `Map<K,V>` | `toSingleValueMap()` Returns the first values contained in this `MultiValueMap`.
    `String` | `toString()`
    `Collection<List<V>>` | `values()`

    - ### Methods inherited from class java.lang.Object

      `clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

- - ### Constructor Detail

    - #### LinkedMultiValueMap

          public LinkedMultiValueMap()

      Create a new LinkedMultiValueMap that wraps a `LinkedHashMap`.

    - #### LinkedMultiValueMap

          public LinkedMultiValueMap(int initialCapacity)

      Create a new LinkedMultiValueMap that wraps a `LinkedHashMap` with the given initial capacity.
      Parameters:
        `initialCapacity` - the initial capacity

    - #### LinkedMultiValueMap

          public LinkedMultiValueMap(Map<K,List<V>> otherMap)

      Copy constructor: Create a new LinkedMultiValueMap with the same mappings as the specified Map.
      Parameters:
        `otherMap` - the Map whose mappings are to be placed in this Map

  - ### Method Detail

    - #### add

          public void add(K key,
                 V value)

      Description copied from interface: `MultiValueMap`
      Add the given single value to the current list of values for the given key.
      Specified by:
        `add` in interface `MultiValueMap<K,V>`
      Parameters:
        `key` - the key
        `value` - the value to be added

    - #### getFirst

          public V getFirst(K key)

      Description copied from interface: `MultiValueMap`
      Return the first value for the given key.
      Specified by:
        `getFirst` in interface `MultiValueMap<K,V>`
      Parameters:
        `key` - the key
      Returns:
        the first value for the specified key, or `null`

    - #### set

          public void set(K key,
                 V value)

      Description copied from interface: `MultiValueMap`
      Set the given single value under the given key.
      Specified by:
        `set` in interface `MultiValueMap<K,V>`
      Parameters:
        `key` - the key
        `value` - the value to set

    - #### setAll

          public void setAll(Map<K,V> values)

      Description copied from interface: `MultiValueMap`
      Set the given values under.
      Specified by:
        `setAll` in interface `MultiValueMap<K,V>`
      Parameters:
        `values` - the values.

    - #### toSingleValueMap

          public Map<K,V> toSingleValueMap()

      Description copied from interface: `MultiValueMap`
      Returns the first values contained in this `MultiValueMap`.
      Specified by:
        `toSingleValueMap` in interface `MultiValueMap<K,V>`
      Returns:
        a single value representation of this map

    - #### size

          public int size()

      Specified by:
        `size` in interface `Map<K,List<V>>`

    - #### isEmpty

          public boolean isEmpty()

      Specified by:
        `isEmpty` in interface `Map<K,List<V>>`

    - #### containsKey

          public boolean containsKey(Object key)

      Specified by:
        `containsKey` in interface `Map<K,List<V>>`

    - #### containsValue

          public boolean containsValue(Object value)

      Specified by:
        `containsValue` in interface `Map<K,List<V>>`

    - #### get

          public List<V> get(Object key)

      Specified by:
        `get` in interface `Map<K,List<V>>`

    - #### put

          public List<V> put(K key,
                    List<V> value)

      Specified by:
        `put` in interface `Map<K,List<V>>`

    - #### remove

          public List<V> remove(Object key)

      Specified by:
        `remove` in interface `Map<K,List<V>>`

    - #### putAll

          public void putAll(Map<? extends K,? extends List<V>> m)

      Specified by:
        `putAll` in interface `Map<K,List<V>>`

    - #### clear

          public void clear()

      Specified by:
        `clear` in interface `Map<K,List<V>>`

    - #### keySet

          public Set<K> keySet()

      Specified by:
        `keySet` in interface `Map<K,List<V>>`

    - #### values

          public Collection<List<V>> values()

      Specified by:
        `values` in interface `Map<K,List<V>>`

    - #### entrySet

          public Set<Map.Entry<K,List<V>>> entrySet()

      Specified by:
        `entrySet` in interface `Map<K,List<V>>`

    - #### equals

          public boolean equals(Object obj)

      Specified by:
        `equals` in interface `Map<K,List<V>>`
      Overrides:
        `equals` in class `Object`

    - #### hashCode

          public int hashCode()

      Specified by:
        `hashCode` in interface `Map<K,List<V>>`
      Overrides:
        `hashCode` in class `Object`

    - #### toString

          public String toString()

      Overrides:
        `toString` in class `Object`