Class IndexedTreeMap<K,V>
- Type Parameters:
K
- the type of keys maintained by this mapV
- the type of mapped values
- All Implemented Interfaces:
IndexedNavigableMap<K,
,V> Cloneable
,Map<K,
,V> NavigableMap<K,
,V> SortedMap<K,
V>
NavigableMap
implementation.
The map is sorted according to the natural
ordering of its keys, or by a Comparator
provided at map
creation time, depending on which constructor is used.
This implementation provides guaranteed log(n) time cost for the containsKey, get, put and remove operations. Algorithms are adaptations of those in Cormen, Leiserson, and Rivest's Introduction to Algorithms.
Note that the ordering maintained by a sorted map (whether or not an explicit comparator is provided) must be consistent with equals if this sorted map is to correctly implement the Map interface. (See Comparable or Comparator for a precise definition of consistent with equals.) This is so because the Map interface is defined in terms of the equals operation, but a map performs all key comparisons using its compareTo (or compare) method, so two keys that are deemed equal by this method are, from the standpoint of the sorted map, equal. The behavior of a sorted map is well-defined even if its ordering is inconsistent with equals; it just fails to obey the general contract of the Map interface.
Note that this implementation is not synchronized.
If multiple threads access a map concurrently, and at least one of the
threads modifies the map structurally, it must be synchronized
externally. (A structural modification is any operation that adds or
deletes one or more mappings; merely changing the value associated
with an existing key is not a structural modification.) This is
typically accomplished by synchronizing on some object that naturally
encapsulates the map.
If no such object exists, the map should be "wrapped" using the
Collections.synchronizedSortedMap
method. This is best done at creation time, to prevent accidental
unsynchronized access to the map:
SortedMap m = Collections.synchronizedSortedMap(new IndexedTreeMap(...));
The iterators returned by the iterator method of the collections
returned by all of this class's "collection view methods" are
fail-fast: if the map is structurally modified at any time after the
iterator is created, in any way except through the iterator's own
remove method, the iterator will throw a ConcurrentModificationException
. Thus, in the face of concurrent
modification, the iterator fails quickly and cleanly, rather than risking
arbitrary, non-deterministic behavior at an undetermined time in the future.
Note that the fail-fast behavior of an iterator cannot be guaranteed as it is, generally speaking, impossible to make any hard guarantees in the presence of unsynchronized concurrent modification. Fail-fast iterators throw ConcurrentModificationException on a best-effort basis. Therefore, it would be wrong to write a program that depended on this exception for its correctness: the fail-fast behavior of iterators should be used only to detect bugs.
All Map.Entry pairs returned by methods in this class and its views represent snapshots of mappings at the time they were produced. They do not support the Entry.setValue method. (Note however that it is possible to change mappings in the associated map using put.)
This class is a member of the Java Collections Framework.
- Since:
- 1.2
- See Also:
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Nested Class Summary
Nested classes/interfaces inherited from class com.macrofocus.utils.AbstractMap
AbstractMap.SimpleEntry<K,
V>, AbstractMap.SimpleImmutableEntry<K, V> -
Constructor Summary
ConstructorsConstructorDescriptionConstructs a new, empty tree map, using the natural ordering of its keys.IndexedTreeMap
(Comparator<? super K> comparator) Constructs a new, empty tree map, ordered according to the given comparator. -
Method Summary
Modifier and TypeMethodDescriptionceilingEntry
(K key) ceilingKey
(K key) void
clear()
Removes all of the mappings from this map.Comparator<? super K>
boolean
containsKey
(Object key) Returns true if this map contains a mapping for the specified key.boolean
containsValue
(Object value) Returns true if this map maps one or more keys to the specified value.void
dbg()
void
debug()
entrySet()
Returns aSet
view of the mappings contained in this map.exactEntry
(int index) Returns a key-value mapping associated with the key located at the index offset from the beginning of the sorted mapexactKey
(int index) Returns the key located at the index offset from the beginning of the sorted mapfirstKey()
floorEntry
(K key) Returns the value to which the specified key is mapped, ornull
if this map contains no mapping for the key.higherEntry
(K key) int
Searches the specified tree map for the specified key using the put algorithm.keySet()
Returns aSet
view of the keys contained in this map.lastKey()
lowerEntry
(K key) Associates the specified value with the specified key in this map.void
Copies all of the mappings from the specified map to this map.Removes the mapping for this key from this IndexedTreeMap if present.int
size()
Returns the number of key-value mappings in this map.values()
Returns aCollection
view of the values contained in this map.Methods inherited from class com.macrofocus.utils.AbstractMap
equals, hashCode, isEmpty, toString
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Methods inherited from interface java.util.Map
compute, computeIfAbsent, computeIfPresent, equals, forEach, getOrDefault, hashCode, isEmpty, merge, putIfAbsent, remove, replace, replace, replaceAll
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Constructor Details
-
IndexedTreeMap
public IndexedTreeMap()Constructs a new, empty tree map, using the natural ordering of its keys. All keys inserted into the map must implement theComparable
interface. Furthermore, all such keys must be mutually comparable: k1.compareTo(k2) must not throw a ClassCastException for any keys k1 and k2 in the map. If the user attempts to put a key into the map that violates this constraint (for example, the user attempts to put a string key into a map whose keys are integers), the put(Object key, Object value) call will throw a ClassCastException. -
IndexedTreeMap
Constructs a new, empty tree map, ordered according to the given comparator. All keys inserted into the map must be mutually comparable by the given comparator: comparator.compare(k1, k2) must not throw a ClassCastException for any keys k1 and k2 in the map. If the user attempts to put a key into the map that violates this constraint, the put(Object key, Object value) call will throw a ClassCastException.- Parameters:
comparator
- the comparator that will be used to order this map. If null, the natural ordering of the keys will be used.
-
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Method Details
-
size
public int size()Returns the number of key-value mappings in this map. -
containsKey
Returns true if this map contains a mapping for the specified key.- Specified by:
containsKey
in interfaceMap<K,
V> - Overrides:
containsKey
in classAbstractMap<K,
V> - Parameters:
key
- key whose presence in this map is to be tested- Returns:
- true if this map contains a mapping for the specified key
- Throws:
ClassCastException
- if the specified key cannot be compared with the keys currently in the mapNullPointerException
- if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys
-
containsValue
Returns true if this map maps one or more keys to the specified value. More formally, returns true if and only if this map contains at least one mapping to a value v such that (value==null ? v==null : value.equals(v)). This operation will probably require time linear in the map size for most implementations.- Specified by:
containsValue
in interfaceMap<K,
V> - Overrides:
containsValue
in classAbstractMap<K,
V> - Parameters:
value
- value whose presence in this map is to be tested- Returns:
- true if a mapping to value exists; false otherwise
- Since:
- 1.2
-
get
Returns the value to which the specified key is mapped, ornull
if this map contains no mapping for the key.More formally, if this map contains a mapping from a key
k
to a valuev
such thatkey
compares equal tok
according to the map's ordering, then this method returnsv
; otherwise it returnsnull
. (There can be at most one such mapping.)A return value of
null
does not necessarily indicate that the map contains no mapping for the key; it's also possible that the map explicitly maps the key tonull
. ThecontainsKey
operation may be used to distinguish these two cases.- Specified by:
get
in interfaceMap<K,
V> - Overrides:
get
in classAbstractMap<K,
V> - Throws:
ClassCastException
- if the specified key cannot be compared with the keys currently in the mapNullPointerException
- if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys
-
comparator
- Specified by:
comparator
in interfaceSortedMap<K,
V>
-
firstKey
- Specified by:
firstKey
in interfaceSortedMap<K,
V> - Throws:
NoSuchElementException
-
lastKey
- Specified by:
lastKey
in interfaceSortedMap<K,
V> - Throws:
NoSuchElementException
-
putAll
Copies all of the mappings from the specified map to this map. These mappings replace any mappings that this map had for any of the keys currently in the specified map.- Specified by:
putAll
in interfaceMap<K,
V> - Overrides:
putAll
in classAbstractMap<K,
V> - Parameters:
map
- mappings to be stored in this map- Throws:
ClassCastException
- if the class of a key or value in the specified map prevents it from being stored in this mapNullPointerException
- if the specified map is null or the specified map contains a null key and this map does not permit null keys
-
debug
- Throws:
Exception
-
dbg
public void dbg() -
put
Associates the specified value with the specified key in this map. If the map previously contained a mapping for the key, the old value is replaced.- Specified by:
put
in interfaceMap<K,
V> - Overrides:
put
in classAbstractMap<K,
V> - Parameters:
key
- key with which the specified value is to be associatedvalue
- 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.)
- Throws:
ClassCastException
- if the specified key cannot be compared with the keys currently in the mapNullPointerException
- if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys
-
remove
Removes the mapping for this key from this IndexedTreeMap if present.- Specified by:
remove
in interfaceMap<K,
V> - Overrides:
remove
in classAbstractMap<K,
V> - Parameters:
key
- key for which mapping should be removed- 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.)
- Throws:
ClassCastException
- if the specified key cannot be compared with the keys currently in the mapNullPointerException
- if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys
-
clear
public void clear()Removes all of the mappings from this map. The map will be empty after this call returns. -
firstEntry
- Specified by:
firstEntry
in interfaceNavigableMap<K,
V> - Since:
- 1.6
-
lastEntry
- Specified by:
lastEntry
in interfaceNavigableMap<K,
V> - Since:
- 1.6
-
pollFirstEntry
- Specified by:
pollFirstEntry
in interfaceNavigableMap<K,
V> - Since:
- 1.6
-
pollLastEntry
- Specified by:
pollLastEntry
in interfaceNavigableMap<K,
V> - Since:
- 1.6
-
lowerEntry
- Specified by:
lowerEntry
in interfaceNavigableMap<K,
V> - Throws:
ClassCastException
NullPointerException
- if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys- Since:
- 1.6
-
lowerKey
- Specified by:
lowerKey
in interfaceNavigableMap<K,
V> - Throws:
ClassCastException
NullPointerException
- if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys- Since:
- 1.6
-
floorEntry
- Specified by:
floorEntry
in interfaceNavigableMap<K,
V> - Throws:
ClassCastException
NullPointerException
- if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys- Since:
- 1.6
-
floorKey
- Specified by:
floorKey
in interfaceNavigableMap<K,
V> - Throws:
ClassCastException
NullPointerException
- if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys- Since:
- 1.6
-
ceilingEntry
- Specified by:
ceilingEntry
in interfaceNavigableMap<K,
V> - Throws:
ClassCastException
NullPointerException
- if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys- Since:
- 1.6
-
ceilingKey
- Specified by:
ceilingKey
in interfaceNavigableMap<K,
V> - Throws:
ClassCastException
NullPointerException
- if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys- Since:
- 1.6
-
higherEntry
- Specified by:
higherEntry
in interfaceNavigableMap<K,
V> - Throws:
ClassCastException
NullPointerException
- if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys- Since:
- 1.6
-
higherKey
- Specified by:
higherKey
in interfaceNavigableMap<K,
V> - Throws:
ClassCastException
NullPointerException
- if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys- Since:
- 1.6
-
exactKey
Description copied from interface:IndexedNavigableMap
Returns the key located at the index offset from the beginning of the sorted map- Specified by:
exactKey
in interfaceIndexedNavigableMap<K,
V> - Parameters:
index
- index of the key- Returns:
- the key
key
located at the index (@code index) offset from the beginning of the sorted map
-
keyIndex
Description copied from interface:IndexedNavigableMap
Searches the specified tree map for the specified key using the put algorithm. Calculates its offset from the beginning of the sorted map using weights.- Specified by:
keyIndex
in interfaceIndexedNavigableMap<K,
V> - Parameters:
key
- the key- Returns:
- index of the search key, if it is contained in the tree map; otherwise a NullPointerException is thrown
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exactEntry
Description copied from interface:IndexedNavigableMap
Returns a key-value mapping associated with the key located at the index offset from the beginning of the sorted map- Specified by:
exactEntry
in interfaceIndexedNavigableMap<K,
V> - Parameters:
index
- index of the key- Returns:
- the entry with the key
key
located at the index (@code index) offset from the beginning of the sorted map
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keySet
Returns aSet
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. -
descendingKeySet
- Specified by:
descendingKeySet
in interfaceNavigableMap<K,
V> - Since:
- 1.6
-
values
Returns aCollection
view of the values contained in this map. The collection's iterator returns the values in ascending order of the corresponding keys. 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. -
entrySet
Returns aSet
view of the mappings contained in this map. The set's iterator returns the entries in ascending key 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, 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. -
descendingMap
- Specified by:
descendingMap
in interfaceNavigableMap<K,
V> - Since:
- 1.6
-
subMap
- Specified by:
subMap
in interfaceNavigableMap<K,
V> - Throws:
ClassCastException
NullPointerException
- if fromKey or toKey is null and this map uses natural ordering, or its comparator does not permit null keysIllegalArgumentException
- Since:
- 1.6
-
headMap
- Specified by:
headMap
in interfaceNavigableMap<K,
V> - Throws:
ClassCastException
NullPointerException
- if toKey is null and this map uses natural ordering, or its comparator does not permit null keysIllegalArgumentException
- Since:
- 1.6
-
tailMap
- Specified by:
tailMap
in interfaceNavigableMap<K,
V> - Throws:
ClassCastException
NullPointerException
- if fromKey is null and this map uses natural ordering, or its comparator does not permit null keysIllegalArgumentException
- Since:
- 1.6
-
subMap
- Specified by:
subMap
in interfaceNavigableMap<K,
V> - Specified by:
subMap
in interfaceSortedMap<K,
V> - Throws:
ClassCastException
NullPointerException
- if fromKey or toKey is null and this map uses natural ordering, or its comparator does not permit null keysIllegalArgumentException
-
headMap
- Specified by:
headMap
in interfaceNavigableMap<K,
V> - Specified by:
headMap
in interfaceSortedMap<K,
V> - Throws:
ClassCastException
NullPointerException
- if toKey is null and this map uses natural ordering, or its comparator does not permit null keysIllegalArgumentException
-
tailMap
- Specified by:
tailMap
in interfaceNavigableMap<K,
V> - Specified by:
tailMap
in interfaceSortedMap<K,
V> - Throws:
ClassCastException
NullPointerException
- if fromKey is null and this map uses natural ordering, or its comparator does not permit null keysIllegalArgumentException
-