public class

DualTreeBidiMap

extends AbstractDualBidiMap
implements Serializable SortedBidiMap
java.lang.Object
   ↳ org.apache.commons.collections.bidimap.AbstractDualBidiMap
     ↳ org.apache.commons.collections.bidimap.DualTreeBidiMap

Class Overview

Implementation of BidiMap that uses two TreeMap instances.

The setValue() method on iterators will succeed only if the new value being set is not already in the bidimap.

When considering whether to use this class, the TreeBidiMap class should also be considered. It implements the interface using a dedicated design, and does not store each object twice, which can save on memory use.

NOTE: From Commons Collections 3.1, all subclasses will use TreeMap and the flawed createMap method is ignored.

Summary

Nested Classes
class DualTreeBidiMap.BidiOrderedMapIterator Inner class MapIterator. 
class DualTreeBidiMap.ViewMap Internal sorted map view. 
Fields
protected final Comparator comparator The comparator to use
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Inherited Fields
From class org.apache.commons.collections.bidimap.AbstractDualBidiMap
Public Constructors
DualTreeBidiMap()
Creates an empty DualTreeBidiMap
DualTreeBidiMap(Map map)
Constructs a DualTreeBidiMap and copies the mappings from specified Map.
DualTreeBidiMap(Comparator comparator)
Constructs a DualTreeBidiMap using the specified Comparator.
Protected Constructors
DualTreeBidiMap(Map normalMap, Map reverseMap, BidiMap inverseBidiMap)
Constructs a DualTreeBidiMap that decorates the specified maps.
Public Methods
Comparator comparator()
Object firstKey()
Gets the first key currently in this map.
SortedMap headMap(Object toKey)
OrderedBidiMap inverseOrderedBidiMap()
Gets a view of this map where the keys and values are reversed.
SortedBidiMap inverseSortedBidiMap()
Gets a view of this map where the keys and values are reversed.
Object lastKey()
Gets the last key currently in this map.
Object nextKey(Object key)
Gets the next key after the one specified.
OrderedMapIterator orderedMapIterator()
Obtains an ordered map iterator.
Object previousKey(Object key)
Gets the previous key before the one specified.
SortedMap subMap(Object fromKey, Object toKey)
SortedMap tailMap(Object fromKey)
Protected Methods
BidiMap createBidiMap(Map normalMap, Map reverseMap, BidiMap inverseMap)
Creates a new instance of this object.
[Expand]
Inherited Methods
From class org.apache.commons.collections.bidimap.AbstractDualBidiMap
From class java.lang.Object
From interface java.util.Map
From interface java.util.SortedMap
From interface org.apache.commons.collections.BidiMap
From interface org.apache.commons.collections.IterableMap
From interface org.apache.commons.collections.OrderedBidiMap
From interface org.apache.commons.collections.OrderedMap
From interface org.apache.commons.collections.SortedBidiMap

Fields

protected final Comparator comparator

The comparator to use

Public Constructors

public DualTreeBidiMap ()

Creates an empty DualTreeBidiMap

public DualTreeBidiMap (Map map)

Constructs a DualTreeBidiMap and copies the mappings from specified Map.

Parameters
map the map whose mappings are to be placed in this map

public DualTreeBidiMap (Comparator comparator)

Constructs a DualTreeBidiMap using the specified Comparator.

Parameters
comparator the Comparator

Protected Constructors

protected DualTreeBidiMap (Map normalMap, Map reverseMap, BidiMap inverseBidiMap)

Constructs a DualTreeBidiMap that decorates the specified maps.

Parameters
normalMap the normal direction map
reverseMap the reverse direction map
inverseBidiMap the inverse BidiMap

Public Methods

public Comparator comparator ()

public Object firstKey ()

Gets the first key currently in this map.

Returns
  • the first key currently in this map

public SortedMap headMap (Object toKey)

public OrderedBidiMap inverseOrderedBidiMap ()

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 equally.

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.

Returns
  • an inverted bidirectional map

public SortedBidiMap inverseSortedBidiMap ()

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 SortedMap.

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.

The inverse map returned by inverseBidiMap() should be the same object as returned by this method.

Returns
  • an inverted bidirectional map

public Object lastKey ()

Gets the last key currently in this map.

Returns
  • the last key currently in this map

public Object nextKey (Object key)

Gets the next key after the one specified.

Parameters
key the key to search for next from
Returns
  • the next key, null if no match or at end

public OrderedMapIterator orderedMapIterator ()

Obtains an ordered map iterator.

This implementation copies the elements to an ArrayList in order to provide the forward/backward behaviour.

Returns
  • a new ordered map iterator

public Object previousKey (Object key)

Gets the previous key before the one specified.

Parameters
key the key to search for previous from
Returns
  • the previous key, null if no match or at start

public SortedMap subMap (Object fromKey, Object toKey)

public SortedMap tailMap (Object fromKey)

Protected Methods

protected BidiMap createBidiMap (Map normalMap, Map reverseMap, BidiMap inverseMap)

Creates a new instance of this object.

Parameters
normalMap the normal direction map
reverseMap the reverse direction map
inverseMap the inverse BidiMap
Returns
  • new bidi map