ForwardingMultimap (Guava: Google Core Libraries for Java 23.4-jre API)

java.lang.Object
- com.google.common.collect.ForwardingObject
- - com.google.common.collect.ForwardingMultimap<K,V>

All Implemented Interfaces:

Multimap<K,V>

Direct Known Subclasses:

ForwardingListMultimap, ForwardingSetMultimap
```
@GwtCompatible
public abstract class ForwardingMultimap<K,V>
extends ForwardingObject
implements Multimap<K,V>
```
A multimap which forwards all its method calls to another multimap. Subclasses should override one or more methods to modify the behavior of the backing multimap as desired per the decorator pattern.
default method warning: This class does not forward calls to default methods. Instead, it inherits their default implementations. When those implementations invoke methods, they invoke methods on the ForwardingMultimap.

Since:

2.0

Author:

Robert Konigsberg

Constructor Summary

Constructors
Modifier Constructor and Description

protected ForwardingMultimap()
Constructor for use by subclasses.

Constructors
Modifier	Constructor and Description
`protected`	`ForwardingMultimap()` Constructor for use by subclasses.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`Map<K,Collection<V>>`	`asMap()` Returns a view of this multimap as a `Map` from each distinct key to the nonempty collection of that key's associated values.
`void`	`clear()` Removes all key-value pairs from the multimap, leaving it empty.
`boolean`	`containsEntry(Object key, Object value)` Returns `true` if this multimap contains at least one key-value pair with the key `key` and the value `value`.
`boolean`	`containsKey(Object key)` Returns `true` if this multimap contains at least one key-value pair with the key `key`.
`boolean`	`containsValue(Object value)` Returns `true` if this multimap contains at least one key-value pair with the value `value`.
`protected abstract Multimap<K,V>`	`delegate()` Returns the backing delegate instance that methods are forwarded to.
`Collection<Map.Entry<K,V>>`	`entries()` Returns a view collection of all key-value pairs contained in this multimap, as `Map.Entry` instances.
`boolean`	`equals(Object object)` Compares the specified object with this multimap for equality.
`Collection<V>`	`get(K key)` Returns a view collection of the values associated with `key` in this multimap, if any.
`int`	`hashCode()` Returns the hash code for this multimap.
`boolean`	`isEmpty()` Returns `true` if this multimap contains no key-value pairs.
`Multiset<K>`	`keys()` Returns a view collection containing the key from each key-value pair in this multimap, without collapsing duplicates.
`Set<K>`	`keySet()` Returns a view collection of all distinct keys contained in this multimap.
`boolean`	`put(K key, V value)` Stores a key-value pair in this multimap.
`boolean`	`putAll(K key, Iterable<? extends V> values)` Stores a key-value pair in this multimap for each of `values`, all using the same key, `key`.
`boolean`	`putAll(Multimap<? extends K,? extends V> multimap)` Stores all key-value pairs of `multimap` in this multimap, in the order returned by `multimap.entries()`.
`boolean`	`remove(Object key, Object value)` Removes a single key-value pair with the key `key` and the value `value` from this multimap, if such exists.
`Collection<V>`	`removeAll(Object key)` Removes all values associated with the key `key`.
`Collection<V>`	`replaceValues(K key, Iterable<? extends V> values)` Stores a collection of values with the same key, replacing any existing values for that key.
`int`	`size()` Returns the number of key-value pairs in this multimap.
`Collection<V>`	`values()` Returns a view collection containing the value from each key-value pair contained in this multimap, without collapsing duplicates (so `values().size() == size()`).

Methods inherited from class com.google.common.collect.ForwardingObject
toString

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.google.common.collect.Multimap
forEach

- Constructor Detail
  - ForwardingMultimap
```
protected ForwardingMultimap()
```
    Constructor for use by subclasses.
- Method Detail
  - delegate
```
protected abstract Multimap<K,V> delegate()
```
    Description copied from class: ForwardingObject
    
    Returns the backing delegate instance that methods are forwarded to. Abstract subclasses generally override this method with an abstract method that has a more specific return type, such as ForwardingSet.delegate(). Concrete subclasses override this method to supply the instance being decorated.
    
    Specified by:
    
    delegate in class ForwardingObject
  - asMap
```
public Map<K,Collection<V>> asMap()
```
    Description copied from interface: Multimap
    
    Returns a view of this multimap as a Map from each distinct key to the nonempty collection of that key's associated values. Note that this.asMap().get(k) is equivalent to this.get(k) only when k is a key contained in the multimap; otherwise it returns null as opposed to an empty collection.
    Changes to the returned map or the collections that serve as its values will update the underlying multimap, and vice versa. The map does not support put or putAll, nor do its entries support setValue.
    
    Specified by:
    
    asMap in interface Multimap<K,V>
  - clear
```
public void clear()
```
    Description copied from interface: Multimap
    
    Removes all key-value pairs from the multimap, leaving it empty.
    
    Specified by:
    
    clear in interface Multimap<K,V>
  - containsEntry
```
public boolean containsEntry(@Nullable
                             Object key,
                             @Nullable
                             Object value)
```
    Description copied from interface: Multimap
    
    Returns true if this multimap contains at least one key-value pair with the key key and the value value.
    
    Specified by:
    
    containsEntry in interface Multimap<K,V>
  - containsKey
```
public boolean containsKey(@Nullable
                           Object key)
```
    Description copied from interface: Multimap
    
    Returns true if this multimap contains at least one key-value pair with the key key.
    
    Specified by:
    
    containsKey in interface Multimap<K,V>
  - containsValue
```
public boolean containsValue(@Nullable
                             Object value)
```
    Description copied from interface: Multimap
    
    Returns true if this multimap contains at least one key-value pair with the value value.
    
    Specified by:
    
    containsValue in interface Multimap<K,V>
  - entries
```
public Collection<Map.Entry<K,V>> entries()
```
    Description copied from interface: Multimap
    
    Returns a view collection of all key-value pairs contained in this multimap, as Map.Entry instances.
    Changes to the returned collection or the entries it contains will update the underlying multimap, and vice versa. However, adding to the returned collection is not possible.
    
    Specified by:
    
    entries in interface Multimap<K,V>
  - get
```
public Collection<V> get(@Nullable
                         K key)
```
    Description copied from interface: Multimap
    
    Returns a view collection of the values associated with key in this multimap, if any. Note that when containsKey(key) is false, this returns an empty collection, not null.
    Changes to the returned collection will update the underlying multimap, and vice versa.
    
    Specified by:
    
    get in interface Multimap<K,V>
  - isEmpty
```
public boolean isEmpty()
```
    Description copied from interface: Multimap
    
    Returns true if this multimap contains no key-value pairs. Equivalent to size() == 0, but can in some cases be more efficient.
    
    Specified by:
    
    isEmpty in interface Multimap<K,V>
  - keys
```
public Multiset<K> keys()
```
    Description copied from interface: Multimap
    
    Returns a view collection containing the key from each key-value pair in this multimap, without collapsing duplicates. This collection has the same size as this multimap, and keys().count(k) == get(k).size() for all k.
    Changes to the returned multiset will update the underlying multimap, and vice versa. However, adding to the returned collection is not possible.
    
    Specified by:
    
    keys in interface Multimap<K,V>
  - keySet
```
public Set<K> keySet()
```
    Description copied from interface: Multimap
    
    Returns a view collection of all distinct keys contained in this multimap. Note that the key set contains a key if and only if this multimap maps that key to at least one value.
    Changes to the returned set will update the underlying multimap, and vice versa. However, adding to the returned set is not possible.
    
    Specified by:
    
    keySet in interface Multimap<K,V>
  - put
```
public boolean put(K key,
                   V value)
```
    Description copied from interface: Multimap
    
    Stores a key-value pair in this multimap.
    Some multimap implementations allow duplicate key-value pairs, in which case put always adds a new key-value pair and increases the multimap size by 1. Other implementations prohibit duplicates, and storing a key-value pair that's already in the multimap has no effect.
    
    Specified by:
    
    put in interface Multimap<K,V>
    
    Returns:
    
    true if the method increased the size of the multimap, or false if the multimap already contained the key-value pair and doesn't allow duplicates
  - putAll
```
public boolean putAll(K key,
                      Iterable<? extends V> values)
```
    Description copied from interface: Multimap
    Stores a key-value pair in this multimap for each of values, all using the same key, key. Equivalent to (but expected to be more efficient than):
```
   

   for (V value : values) {
     put(key, value);
   }
```
    In particular, this is a no-op if values is empty.
    Specified by:
    
    putAll in interface Multimap<K,V>
    
    Returns:
    
    true if the multimap changed
  - putAll
```
public boolean putAll(Multimap<? extends K,? extends V> multimap)
```
    Description copied from interface: Multimap
    
    Stores all key-value pairs of multimap in this multimap, in the order returned by multimap.entries().
    
    Specified by:
    
    putAll in interface Multimap<K,V>
    
    Returns:
    
    true if the multimap changed
  - remove
```
public boolean remove(@Nullable
                      Object key,
                      @Nullable
                      Object value)
```
    Description copied from interface: Multimap
    
    Removes a single key-value pair with the key key and the value value from this multimap, if such exists. If multiple key-value pairs in the multimap fit this description, which one is removed is unspecified.
    
    Specified by:
    
    remove in interface Multimap<K,V>
    
    Returns:
    
    true if the multimap changed
  - removeAll
```
public Collection<V> removeAll(@Nullable
                               Object key)
```
    Description copied from interface: Multimap
    
    Removes all values associated with the key key.
    Once this method returns, key will not be mapped to any values, so it will not appear in Multimap.keySet(), Multimap.asMap(), or any other views.
    
    Specified by:
    
    removeAll in interface Multimap<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.
  - replaceValues
```
public Collection<V> replaceValues(K key,
                                   Iterable<? extends V> values)
```
    Description copied from interface: Multimap
    
    Stores a collection of values with the same key, replacing any existing values for that key.
    If values is empty, this is equivalent to removeAll(key).
    
    Specified by:
    
    replaceValues in interface Multimap<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.
  - 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() or asMap().size(). See the opening section of the Multimap class documentation for clarification.
    
    Specified by:
    
    size in interface Multimap<K,V>
  - values
```
public Collection<V> values()
```
    Description copied from interface: Multimap
    
    Returns a view collection containing the value from each key-value pair contained in this multimap, without collapsing duplicates (so values().size() == size()).
    Changes to the returned collection will update the underlying multimap, and vice versa. However, adding to the returned collection is not possible.
    
    Specified by:
    
    values in interface Multimap<K,V>
  - equals
```
public boolean equals(@Nullable
                      Object object)
```
    Description copied from interface: Multimap
    
    Compares the specified object with this multimap for equality. Two multimaps are equal when their map views, as returned by Multimap.asMap(), are also equal.
    In general, two multimaps with identical key-value mappings may or may not be equal, depending on the implementation. For example, two SetMultimap instances with the same key-value mappings are equal, but equality of two ListMultimap instances depends on the ordering of the values for each key.
    A non-empty SetMultimap cannot be equal to a non-empty ListMultimap, since their Multimap.asMap() views contain unequal collections as values. However, any two empty multimaps are equal, because they both have empty Multimap.asMap() views.
    
    Specified by:
    
    equals in interface Multimap<K,V>
    
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Description copied from interface: Multimap
    
    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().
    In general, two multimaps with identical key-value mappings may or may not have the same hash codes, depending on the implementation. For example, two SetMultimap instances with the same key-value mappings will have the same hashCode, but the hashCode of ListMultimap instances depends on the ordering of the values for each key.
    
    Specified by:
    
    hashCode in interface Multimap<K,V>
    
    Overrides:
    
    hashCode in class Object

Class ForwardingMultimap<K,V>

Constructor Summary

Method Summary

Methods inherited from class com.google.common.collect.ForwardingObject

Methods inherited from class java.lang.Object

Methods inherited from interface com.google.common.collect.Multimap

Constructor Detail

ForwardingMultimap

Method Detail

delegate

asMap

clear

containsEntry

containsKey

containsValue

entries

get

isEmpty

keys

keySet

put

putAll

putAll

remove

removeAll

replaceValues

size

values

equals

hashCode