Package com.google.common.collect

Class ForwardingNavigableMap.StandardDescendingMap

java.lang.Object

com.google.common.collect.ForwardingObject

com.google.common.collect.ForwardingMap<K,V>

com.google.common.collect.ForwardingNavigableMap.StandardDescendingMap

All Implemented Interfaces:

Map<K,V>, NavigableMap<K,V>, SortedMap<K,V>

Enclosing class:

ForwardingNavigableMap<K,V>

@Beta
protected class ForwardingNavigableMap.StandardDescendingMap
extends ForwardingMap<K,V>

A sensible implementation of NavigableMap.descendingMap() in terms of the methods of this NavigableMap. In many cases, you may wish to override ForwardingNavigableMap.descendingMap() to forward to this implementation or a subclass thereof.

In particular, this map iterates over entries with repeated calls to NavigableMap.lowerEntry(K). If a more efficient means of iteration is available, you may wish to override the entryIterator() method of this class.

Since:

12.0

Nested Class Summary

Nested classes/interfaces inherited from class com.google.common.collect.ForwardingMap

ForwardingMap.StandardEntrySet, ForwardingMap.StandardKeySet, ForwardingMap.StandardValues

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

Map.Entry<K,V>

Constructor Summary

Constructors

Constructor	Description
StandardDescendingMap()	Constructor for use by subclasses.

Method Summary

Modifier and Type	Method	Description
Map.Entry<K,V>	ceilingEntry(K key)	Returns a key-value mapping associated with the least key greater than or equal to the given key, or null if there is no such key.
K	ceilingKey(K key)	Returns the least key greater than or equal to the given key, or null if there is no such key.
Comparator<? super K>	comparator()	Returns the comparator used to order the keys in this map, or null if this map uses the natural ordering of its keys.
protected Map<K,V>	delegate()	Returns the backing delegate instance that methods are forwarded to.
NavigableSet<K>	descendingKeySet()	Returns a reverse order NavigableSet view of the keys contained in this map.
NavigableMap<K,V>	descendingMap()	Returns a reverse order view of the mappings contained in this map.
protected Iterator<Map.Entry<K,V>>	entryIterator()
Set<Map.Entry<K,V>>	entrySet()	Returns a Set view of the mappings contained in this map.
Map.Entry<K,V>	firstEntry()	Returns a key-value mapping associated with the least key in this map, or null if the map is empty.
K	firstKey()	Returns the first (lowest) key currently in this map.
Map.Entry<K,V>	floorEntry(K key)	Returns a key-value mapping associated with the greatest key less than or equal to the given key, or null if there is no such key.
K	floorKey(K key)	Returns the greatest key less than or equal to the given key, or null if there is no such key.
SortedMap<K,V>	headMap(K toKey)	Returns a view of the portion of this map whose keys are strictly less than toKey.
NavigableMap<K,V>	headMap(K toKey, boolean inclusive)	Returns a view of the portion of this map whose keys are less than (or equal to, if inclusive is true) toKey.
Map.Entry<K,V>	higherEntry(K key)	Returns a key-value mapping associated with the least key strictly greater than the given key, or null if there is no such key.
K	higherKey(K key)	Returns the least key strictly greater than the given key, or null if there is no such key.
Set<K>	keySet()	Returns a Set view of the keys contained in this map.
Map.Entry<K,V>	lastEntry()	Returns a key-value mapping associated with the greatest key in this map, or null if the map is empty.
K	lastKey()	Returns the last (highest) key currently in this map.
Map.Entry<K,V>	lowerEntry(K key)	Returns a key-value mapping associated with the greatest key strictly less than the given key, or null if there is no such key.
K	lowerKey(K key)	Returns the greatest key strictly less than the given key, or null if there is no such key.
NavigableSet<K>	navigableKeySet()	Returns a NavigableSet view of the keys contained in this map.
Map.Entry<K,V>	pollFirstEntry()	Removes and returns a key-value mapping associated with the least key in this map, or null if the map is empty.
Map.Entry<K,V>	pollLastEntry()	Removes and returns a key-value mapping associated with the greatest key in this map, or null if the map is empty.
NavigableMap<K,V>	subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive)	Returns a view of the portion of this map whose keys range from fromKey to toKey.
SortedMap<K,V>	subMap(K fromKey, K toKey)	Returns a view of the portion of this map whose keys range from fromKey, inclusive, to toKey, exclusive.
SortedMap<K,V>	tailMap(K fromKey)	Returns a view of the portion of this map whose keys are greater than or equal to fromKey.
NavigableMap<K,V>	tailMap(K fromKey, boolean inclusive)	Returns a view of the portion of this map whose keys are greater than (or equal to, if inclusive is true) fromKey.
String	toString()	Returns the string representation generated by the delegate's toString method.
Collection<V>	values()	Returns a Collection view of the values contained in this map.

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

clear, containsKey, containsValue, equals, get, hashCode, isEmpty, put, putAll, remove, size, standardClear, standardContainsKey, standardContainsValue, standardEquals, standardHashCode, standardIsEmpty, standardPutAll, standardRemove, standardToString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

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

Constructor Detail

StandardDescendingMap

public StandardDescendingMap()

Constructor for use by subclasses.

Method Detail

entryIterator

protected Iterator<Map.Entry<K,V>> entryIterator()

delegate

protected final Map<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 ForwardingMap<K,V>

comparator

public Comparator<? super K> comparator()

Description copied from interface: java.util.SortedMap

Returns the comparator used to order the keys in this map, or null if this map uses the natural ordering of its keys.

Specified by:

comparator in interface SortedMap<K,V>

Returns:

the comparator used to order the keys in this map, or null if this map uses the natural ordering of its keys

firstKey

public K firstKey()

Description copied from interface: java.util.SortedMap

Returns the first (lowest) key currently in this map.

Specified by:

firstKey in interface SortedMap<K,V>

Returns:

the first (lowest) key currently in this map

lastKey

public K lastKey()

Description copied from interface: java.util.SortedMap

Returns the last (highest) key currently in this map.

Specified by:

lastKey in interface SortedMap<K,V>

Returns:

the last (highest) key currently in this map

lowerEntry

public Map.Entry<K,V> lowerEntry(K key)

Description copied from interface: java.util.NavigableMap

Returns a key-value mapping associated with the greatest key strictly less than the given key, or null if there is no such key.

Specified by:

lowerEntry in interface NavigableMap<K,V>

Parameters:

key - the key

Returns:

an entry with the greatest key less than key, or null if there is no such key

lowerKey

public K lowerKey(K key)

Description copied from interface: java.util.NavigableMap

Returns the greatest key strictly less than the given key, or null if there is no such key.

Specified by:

lowerKey in interface NavigableMap<K,V>

Parameters:

key - the key

Returns:

the greatest key less than key, or null if there is no such key

floorEntry

public Map.Entry<K,V> floorEntry(K key)

Description copied from interface: java.util.NavigableMap

Returns a key-value mapping associated with the greatest key less than or equal to the given key, or null if there is no such key.

Specified by:

floorEntry in interface NavigableMap<K,V>

Parameters:

key - the key

Returns:

an entry with the greatest key less than or equal to key, or null if there is no such key

floorKey

public K floorKey(K key)

Description copied from interface: java.util.NavigableMap

Returns the greatest key less than or equal to the given key, or null if there is no such key.

Specified by:

floorKey in interface NavigableMap<K,V>

Parameters:

key - the key

Returns:

the greatest key less than or equal to key, or null if there is no such key

ceilingEntry

public Map.Entry<K,V> ceilingEntry(K key)

Description copied from interface: java.util.NavigableMap

Returns a key-value mapping associated with the least key greater than or equal to the given key, or null if there is no such key.

Specified by:

ceilingEntry in interface NavigableMap<K,V>

Parameters:

key - the key

Returns:

an entry with the least key greater than or equal to key, or null if there is no such key

ceilingKey

public K ceilingKey(K key)

Description copied from interface: java.util.NavigableMap

Returns the least key greater than or equal to the given key, or null if there is no such key.

Specified by:

ceilingKey in interface NavigableMap<K,V>

Parameters:

key - the key

Returns:

the least key greater than or equal to key, or null if there is no such key

higherEntry

public Map.Entry<K,V> higherEntry(K key)

Description copied from interface: java.util.NavigableMap

Returns a key-value mapping associated with the least key strictly greater than the given key, or null if there is no such key.

Specified by:

higherEntry in interface NavigableMap<K,V>

Parameters:

key - the key

Returns:

an entry with the least key greater than key, or null if there is no such key

higherKey

public K higherKey(K key)

Description copied from interface: java.util.NavigableMap

Returns the least key strictly greater than the given key, or null if there is no such key.

Specified by:

higherKey in interface NavigableMap<K,V>

Parameters:

key - the key

Returns:

the least key greater than key, or null if there is no such key

firstEntry

public Map.Entry<K,V> firstEntry()

Description copied from interface: java.util.NavigableMap

Returns a key-value mapping associated with the least key in this map, or null if the map is empty.

Specified by:

firstEntry in interface NavigableMap<K,V>

Returns:

an entry with the least key, or null if this map is empty

lastEntry

public Map.Entry<K,V> lastEntry()

Description copied from interface: java.util.NavigableMap

Returns a key-value mapping associated with the greatest key in this map, or null if the map is empty.

Specified by:

lastEntry in interface NavigableMap<K,V>

Returns:

an entry with the greatest key, or null if this map is empty

pollFirstEntry

public Map.Entry<K,V> pollFirstEntry()

Description copied from interface: java.util.NavigableMap

Removes and returns a key-value mapping associated with the least key in this map, or null if the map is empty.

Specified by:

pollFirstEntry in interface NavigableMap<K,V>

Returns:

the removed first entry of this map, or null if this map is empty

pollLastEntry

public Map.Entry<K,V> pollLastEntry()

Description copied from interface: java.util.NavigableMap

Removes and returns a key-value mapping associated with the greatest key in this map, or null if the map is empty.

Specified by:

pollLastEntry in interface NavigableMap<K,V>

Returns:

the removed last entry of this map, or null if this map is empty

descendingMap

public NavigableMap<K,V> descendingMap()

Description copied from interface: java.util.NavigableMap

Returns a reverse order view of the mappings contained in this map. The descending map is backed by this map, so changes to the map are reflected in the descending map, and vice-versa. If either map is modified while an iteration over a collection view of either map is in progress (except through the iterator's own remove operation), the results of the iteration are undefined.

The returned map has an ordering equivalent to Collections.reverseOrder(comparator()). The expression m.descendingMap().descendingMap() returns a view of m essentially equivalent to m.

Specified by:

descendingMap in interface NavigableMap<K,V>

Returns:

a reverse order view of this map

entrySet

public Set<Map.Entry<K,V>> entrySet()

Description copied from interface: java.util.Map

Returns a Set view of the mappings contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own remove operation, or through the setValue operation on a map entry returned by the iterator) the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Set.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.

Specified by:

entrySet in interface Map<K,V>

Specified by:

entrySet in interface SortedMap<K,V>

Overrides:

entrySet in class ForwardingMap<K,V>

Returns:

a set view of the mappings contained in this map

keySet

public Set<K> keySet()

Description copied from interface: java.util.Map

Returns a Set view of the keys contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Set.remove, removeAll, retainAll, and clear operations. It does not support the add or addAll operations.

Specified by:

keySet in interface Map<K,V>

Specified by:

keySet in interface SortedMap<K,V>

Overrides:

keySet in class ForwardingMap<K,V>

Returns:

a set view of the keys contained in this map

navigableKeySet

public NavigableSet<K> navigableKeySet()

Description copied from interface: java.util.NavigableMap

Returns a NavigableSet view of the keys contained in this map. The set's iterator returns the keys in ascending order. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Set.remove, removeAll, retainAll, and clear operations. It does not support the add or addAll operations.

Specified by:

navigableKeySet in interface NavigableMap<K,V>

Returns:

a navigable set view of the keys in this map

descendingKeySet

public NavigableSet<K> descendingKeySet()

Description copied from interface: java.util.NavigableMap

Returns a reverse order NavigableSet view of the keys contained in this map. The set's iterator returns the keys in descending order. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Set.remove, removeAll, retainAll, and clear operations. It does not support the add or addAll operations.

Specified by:

descendingKeySet in interface NavigableMap<K,V>

Returns:

a reverse order navigable set view of the keys in this map

subMap

public NavigableMap<K,V> subMap(K fromKey,
                                      boolean fromInclusive,
                                      K toKey,
                                      boolean toInclusive)

Description copied from interface: java.util.NavigableMap

Returns a view of the portion of this map whose keys range from fromKey to toKey. If fromKey and toKey are equal, the returned map is empty unless fromInclusive and toInclusive are both true. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports.

The returned map will throw an IllegalArgumentException on an attempt to insert a key outside of its range, or to construct a submap either of whose endpoints lie outside its range.

Specified by:

subMap in interface NavigableMap<K,V>

Parameters:

fromKey - low endpoint of the keys in the returned map

fromInclusive - true if the low endpoint is to be included in the returned view

toKey - high endpoint of the keys in the returned map

toInclusive - true if the high endpoint is to be included in the returned view

Returns:

a view of the portion of this map whose keys range from fromKey to toKey

subMap

public SortedMap<K,V> subMap(K fromKey,
                                   K toKey)

Description copied from interface: java.util.NavigableMap

Returns a view of the portion of this map whose keys range from fromKey, inclusive, to toKey, exclusive. (If fromKey and toKey are equal, the returned map is empty.) The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports.

The returned map will throw an IllegalArgumentException on an attempt to insert a key outside its range.

Equivalent to subMap(fromKey, true, toKey, false).

Specified by:

subMap in interface NavigableMap<K,V>

Specified by:

subMap in interface SortedMap<K,V>

Parameters:

fromKey - low endpoint (inclusive) of the keys in the returned map

toKey - high endpoint (exclusive) of the keys in the returned map

Returns:

a view of the portion of this map whose keys range from fromKey, inclusive, to toKey, exclusive

headMap

public NavigableMap<K,V> headMap(K toKey,
                                       boolean inclusive)

Description copied from interface: java.util.NavigableMap

Returns a view of the portion of this map whose keys are less than (or equal to, if inclusive is true) toKey. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports.

The returned map will throw an IllegalArgumentException on an attempt to insert a key outside its range.

Specified by:

headMap in interface NavigableMap<K,V>

Parameters:

toKey - high endpoint of the keys in the returned map

inclusive - true if the high endpoint is to be included in the returned view

Returns:

a view of the portion of this map whose keys are less than (or equal to, if inclusive is true) toKey

headMap

public SortedMap<K,V> headMap(K toKey)

Description copied from interface: java.util.NavigableMap

Returns a view of the portion of this map whose keys are strictly less than toKey. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports.

The returned map will throw an IllegalArgumentException on an attempt to insert a key outside its range.

Equivalent to headMap(toKey, false).

Specified by:

headMap in interface NavigableMap<K,V>

Specified by:

headMap in interface SortedMap<K,V>

Parameters:

toKey - high endpoint (exclusive) of the keys in the returned map

Returns:

a view of the portion of this map whose keys are strictly less than toKey

tailMap

public NavigableMap<K,V> tailMap(K fromKey,
                                       boolean inclusive)

Description copied from interface: java.util.NavigableMap

Returns a view of the portion of this map whose keys are greater than (or equal to, if inclusive is true) fromKey. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports.

The returned map will throw an IllegalArgumentException on an attempt to insert a key outside its range.

Specified by:

tailMap in interface NavigableMap<K,V>

Parameters:

fromKey - low endpoint of the keys in the returned map

inclusive - true if the low endpoint is to be included in the returned view

Returns:

a view of the portion of this map whose keys are greater than (or equal to, if inclusive is true) fromKey

tailMap

public SortedMap<K,V> tailMap(K fromKey)

Description copied from interface: java.util.NavigableMap

Returns a view of the portion of this map whose keys are greater than or equal to fromKey. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports.

The returned map will throw an IllegalArgumentException on an attempt to insert a key outside its range.

Equivalent to tailMap(fromKey, true).

Specified by:

tailMap in interface NavigableMap<K,V>

Specified by:

tailMap in interface SortedMap<K,V>

Parameters:

fromKey - low endpoint (inclusive) of the keys in the returned map

Returns:

a view of the portion of this map whose keys are greater than or equal to fromKey

values

public Collection<V> values()

Description copied from interface: java.util.Map

Returns a Collection view of the values contained in this map. The collection is backed by the map, so changes to the map are reflected in the collection, and vice-versa. If the map is modified while an iteration over the collection is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The collection supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Collection.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.

Specified by:

values in interface Map<K,V>

Specified by:

values in interface SortedMap<K,V>

Overrides:

values in class ForwardingMap<K,V>

Returns:

a collection view of the values contained in this map

toString

public String toString()

Description copied from class: ForwardingObject

Returns the string representation generated by the delegate's toString method.

Overrides:

toString in class ForwardingObject

Returns:

a string representation of the object.