Package org.apache.commons.collections.bidimap

Class UnmodifiableBidiMap

    • Nested Class Summary

      • Nested classes/interfaces inherited from interface java.util.Map

        java.util.Map.Entry<K extends java.lang.Object,​V extends java.lang.Object>

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void clear()  
      static BidiMap decorate​(BidiMap map)
      Factory method to create an unmodifiable map.
      java.util.Set entrySet()  
      BidiMap inverseBidiMap()
      Gets a view of this map where the keys and values are reversed.
      java.util.Set keySet()  
      MapIterator mapIterator()
      Obtains a MapIterator over the map.
      java.lang.Object put​(java.lang.Object key, java.lang.Object value)
      Puts the key-value pair into the map, replacing any previous pair.
      void putAll​(java.util.Map mapToCopy)  
      java.lang.Object remove​(java.lang.Object key)  
      java.lang.Object removeValue​(java.lang.Object value)
      Removes the key-value pair that is currently mapped to the specified value (optional operation).
      java.util.Collection values()  

      • Methods inherited from class java.lang.Object

        getClass, notify, notifyAll, wait, wait, wait

      • Methods inherited from interface java.util.Map

        compute, computeIfAbsent, computeIfPresent, containsKey, containsValue, equals, forEach, get, getOrDefault, hashCode, isEmpty, merge, putIfAbsent, remove, replace, replace, replaceAll, size

    • Method Detail

      • decorate

        public static BidiMap decorate​(BidiMap map)
        Factory method to create an unmodifiable map.

        If the map passed in is already unmodifiable, it is returned.

        Parameters:
        map - the map to decorate, must not be null
        Returns:
        an unmodifiable BidiMap
        Throws:
        java.lang.IllegalArgumentException - if map is null

      • clear

        public void clear()
        Specified by:
        clear in interface java.util.Map
        Overrides:
        clear in class AbstractMapDecorator

      • put

        public java.lang.Object put​(java.lang.Object key,
                            java.lang.Object value)
        Description copied from interface: BidiMap
        Puts the key-value pair into the map, replacing any previous pair.

        When adding a key-value pair, the value may already exist in the map against a different key. That mapping is removed, to ensure that the value only occurs once in the inverse map. 

          BidiMap map1 = new DualHashBidiMap();
  map.put("A","B");  // contains A mapped to B, as per Map
  map.put("A","C");  // contains A mapped to C, as per Map
 
  BidiMap map2 = new DualHashBidiMap();
  map.put("A","B");  // contains A mapped to B, as per Map
  map.put("C","B");  // contains C mapped to B, key A is removed
        Specified by:
        put in interface BidiMap
        Specified by:
        put in interface java.util.Map
        Overrides:
        put in class AbstractMapDecorator
        Parameters:
        key - the key to store
        value - the value to store
        Returns:
        the previous value mapped to this key

      • putAll

        public void putAll​(java.util.Map mapToCopy)
        Specified by:
        putAll in interface java.util.Map
        Overrides:
        putAll in class AbstractMapDecorator

      • remove

        public java.lang.Object remove​(java.lang.Object key)
        Specified by:
        remove in interface java.util.Map
        Overrides:
        remove in class AbstractMapDecorator

      • entrySet

        public java.util.Set entrySet()
        Specified by:
        entrySet in interface java.util.Map
        Overrides:
        entrySet in class AbstractMapDecorator

      • keySet

        public java.util.Set keySet()
        Specified by:
        keySet in interface java.util.Map
        Overrides:
        keySet in class AbstractMapDecorator

      • values

        public java.util.Collection values()
        Specified by:
        values in interface java.util.Map
        Overrides:
        values in class AbstractMapDecorator

      • removeValue

        public java.lang.Object removeValue​(java.lang.Object value)
        Description copied from interface: BidiMap
        Removes the key-value pair that is currently mapped to the specified value (optional operation).

        If the value is not contained in the map, null is returned.

        Implementations should seek to make this method perform equally as well as remove(Object).

        Specified by:
        removeValue in interface BidiMap
        Overrides:
        removeValue in class AbstractBidiMapDecorator
        Parameters:
        value - the value to find the key-value pair for
        Returns:
        the key that was removed, null if nothing removed

      • mapIterator

        public MapIterator mapIterator()
        Description copied from interface: BidiMap
        Obtains a MapIterator over the map.

        A map iterator is an efficient way of iterating over maps. It does not require that the map is stored using Map Entry objects which can increase performance. 

         BidiMap map = new DualHashBidiMap();
 MapIterator it = map.mapIterator();
 while (it.hasNext()) {
   Object key = it.next();
   Object value = it.getValue();
   it.setValue("newValue");
 }
        Specified by:
        mapIterator in interface BidiMap
        Specified by:
        mapIterator in interface IterableMap
        Overrides:
        mapIterator in class AbstractBidiMapDecorator
        Returns:
        a map iterator

      • inverseBidiMap

        public BidiMap inverseBidiMap()
        Description copied from interface: BidiMap
        Gets a view of this map where the keys and values are reversed.

        Changes to one map will be visible in the other and vice versa. This enables both directions of the map to be accessed as a Map.

        Implementations should seek to avoid creating a new object every time this method is called. See AbstractMap.values() etc. Calling this method on the inverse map should return the original.

        Specified by:
        inverseBidiMap in interface BidiMap
        Overrides:
        inverseBidiMap in class AbstractBidiMapDecorator
        Returns:
        an inverted bidirectional map