Package org.jboss.weld.util.collections

Interface Multimap<K,V>

Type Parameters:
K - The key
V - The value
All Known Implementing Classes:
ListMultimap, SetMultimap
public interface Multimap<K,V>
A collection-like structure that maps keys to collections of values.
Author:
Martin Kouba

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    clear()
    Removes all of the mappings.
    boolean
    containsKey(Object key)
     
    Set<Map.Entry<K,Collection<V>>>
    entrySet()
    Map.Entry.getValue() always returns an unmodifiable collection.
    Collection<V>
    get(K key)
    This method never returns null.
    boolean
    isEmpty()
     
    Set<K>
    keySet()
     
    boolean
    put(K key, V value)
     
    boolean
    putAll(K key, Collection<? extends V> values)
     
    Collection<V>
    replaceValues(K key, Iterable<? extends V> values)
    Note that the original collection of values is completely replaced by a new collection which contains all elements from the given iterable.
    int
    size()
    Unlike Guava'sMultimap#size() this method returns the number of key-value mappings.
    Set<V>
    uniqueValues()
     
    List<V>
    values()
    The list may include the same value multiple times if it occurs in multiple mappings or if the collection of values for the mapping allows duplicate elements.

  • Method Details

    • size

      int size()
      Unlike Guava'sMultimap#size() this method returns the number of key-value mappings.
      Returns:
      the number of key-value mappings

    • isEmpty

      boolean isEmpty()
      Returns:
      true if there are no key-value mappings

    • get

      Collection<V> get(K key)
      This method never returns null. If no collection of values for a given key exists a new value collection is initialized.
      Parameters:
      key -
      Returns:
      the collection of values for the given key

    • put

      boolean put(K key, V value)
      Parameters:
      key -
      value -
      Returns:
      true if the the size of the collection associated with the given key increased, false otherwise (e.g. if the collection of values doesn't allow duplicates)

    • putAll

      boolean putAll(K key, Collection<? extends V> values)
      Parameters:
      key -
      values -
      Returns:
      true if the the size of the collection associated with the given key increased, false otherwise (e.g. if the collection of values doesn't allow duplicates)

    • replaceValues

      Collection<V> replaceValues(K key, Iterable<? extends V> values)
      Note that the original collection of values is completely replaced by a new collection which contains all elements from the given iterable. If the collection of values doesn't allow duplicates, these elements are removed.
      Parameters:
      key -
      values -
      Returns:
      the collection of replaced values

    • containsKey

      boolean containsKey(Object key)
      Parameters:
      key -
      Returns:
      true if the multimap contains a mapping for the given key

    • keySet

      Set<K> keySet()
      Returns:
      an immutable set of keys

    • values

      List<V> values()
      The list may include the same value multiple times if it occurs in multiple mappings or if the collection of values for the mapping allows duplicate elements.
      Returns:
      an immutable list of all the values in the multimap

    • uniqueValues

      Set<V> uniqueValues()
      Returns:
      an immutable set of all the values in the multimap

    • entrySet

      Set<Map.Entry<K,Collection<V>>> entrySet()
      Map.Entry.getValue() always returns an unmodifiable collection. Map.Entry.setValue(Object) operation is not supported.
      Returns:
      an immutable set of all key-value pairs

    • clear

      void clear()
      Removes all of the mappings.