Class UnmodifiableMap<K,​V>

    • Method Detail

      • unmodifiableMap

        public static <K,​V> Map<K,​V> unmodifiableMap​(Map<? extends K,​? extends V> map)
        Factory method to create an unmodifiable map.
        Type Parameters:
        K - the key type
        V - the value type
        Parameters:
        map - the map to decorate, must not be null
        Returns:
        a new unmodifiable map
        Throws:
        NullPointerException - if map is null
        Since:
        4.0
      • put

        public V put​(K key,
                     V value)
        Description copied from interface: Put
        Note that the return type is Object, rather than V as in the Map interface. See the class Javadoc for further info.
        Specified by:
        put in interface Map<K,​V>
        Specified by:
        put in interface Put<K,​V>
        Overrides:
        put in class AbstractMapDecorator<K,​V>
        Parameters:
        key - key with which the specified value is to be associated
        value - value to be associated with the specified key
        Returns:
        the previous value associated with key, or null if there was no mapping for key. (A null return can also indicate that the map previously associated null with key, if the implementation supports null values.)
        See Also:
        Map.put(Object, Object)
      • remove

        public V remove​(Object key)
        Specified by:
        remove in interface Get<K,​V>
        Specified by:
        remove in interface Map<K,​V>
        Overrides:
        remove in class AbstractMapDecorator<K,​V>
        Parameters:
        key - key whose mapping is to be removed from the map
        Returns:
        the previous value associated with key, or null if there was no mapping for key.
        See Also:
        Map.remove(Object)
      • mapIterator

        public MapIterator<K,​V> mapIterator()
        Description copied from class: AbstractIterableMap
        Obtains a MapIterator over the map.

        A map iterator is an efficient way of iterating over maps. There is no need to access the entry set or use Map Entry objects.

         IterableMap<String,Integer> map = new HashedMap<String,Integer>();
         MapIterator<String,Integer> it = map.mapIterator();
         while (it.hasNext()) {
           String key = it.next();
           Integer value = it.getValue();
           it.setValue(value + 1);
         }
         
        Specified by:
        mapIterator in interface IterableGet<K,​V>
        Overrides:
        mapIterator in class AbstractIterableMap<K,​V>
        Returns:
        a map iterator