Summary: Ctors | Methods | Inherited Methods | [Expand All]

public class

TreeMap

extends AbstractMap<K, V>
implements Serializable Cloneable SortedMap<K, V>

java.lang.Object
↳	java.util.AbstractMap<K, V>
	↳	java.util.TreeMap<K, V>

Class Overview

TreeMap is an implementation of SortedMap. All optional operations are supported, adding and removing. The values can be any objects. The keys can be any objects which are comparable to each other either using their natural order or a specified Comparator.

Summary

Public Constructors
	TreeMap() Constructs a new empty instance of TreeMap.
	TreeMap(Comparator<? super K> comparator) Constructs a new empty instance of TreeMap which uses the specified Comparator.
	TreeMap(Map<? extends K, ? extends V> map) Constructs a new instance of TreeMap containing the mappings from the specified Map and using the natural ordering.
	TreeMap(SortedMap<K, ? extends V> map) Constructs a new instance of TreeMap containing the mappings from the specified SortedMap and using the same Comparator.

Public Methods
void	clear() Removes all mappings from this TreeMap, leaving it empty.
Object	clone() Returns a new TreeMap with the same mappings, size and comparator as this TreeMap.
Comparator<? super K>	comparator() Returns the Comparator used to compare elements in this TreeMap.
boolean	containsKey(Object key) Searches this TreeMap for the specified key.
boolean	containsValue(Object value) Searches this TreeMap for the specified value.
Set<Entry<K, V>>	entrySet() Returns a Set of the mappings contained in this TreeMap.
K	firstKey() Answer the first sorted key in this TreeMap.
V	get(Object key) Returns the value of the mapping with the specified key.
SortedMap<K, V>	headMap(K endKey) Returns a SortedMap of the specified portion of this TreeMap which contains keys less than the end key.
Set<K>	keySet() Returns a Set of the keys contained in this TreeMap.
K	lastKey() Answer the last sorted key in this TreeMap.
V	put(K key, V value) Maps the specified key to the specified value.
void	putAll(Map<? extends K, ? extends V> map) Copies every mapping in the specified Map to this TreeMap.
V	remove(Object key) Removes a mapping with the specified key from this TreeMap.
int	size() Returns the number of mappings in this TreeMap.
SortedMap<K, V>	subMap(K startKey, K endKey) Returns a SortedMap of the specified portion of this TreeMap which contains keys greater or equal to the start key but less than the end key.
SortedMap<K, V>	tailMap(K startKey) Returns a SortedMap of the specified portion of this TreeMap which contains keys greater or equal to the start key.
Collection<V>	values() Returns a Collection of the values contained in this TreeMap.

[Expand]

Inherited Methods

From class java.util.AbstractMap

void	clear() Removes all elements from this Map, leaving it empty.
Object	clone() Returns a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
boolean	containsKey(Object key) Searches this Map for the specified key.
boolean	containsValue(Object value) Searches this Map for the specified value.
abstract Set<Entry<K, V>>	entrySet() Returns a set view of the mappings contained in this map.
boolean	equals(Object object) Compares the specified object to this Map and answer if they are equal.
V	get(Object key) Returns the value of the mapping with the specified key.
int	hashCode() Returns an integer hash code for the receiver.
boolean	isEmpty() Returns if this Map has no elements, a size of zero.
Set<K>	keySet() Returns a Set of the keys contained in this Map.
V	put(K key, V value) Maps the specified key to the specified value.
void	putAll(Map<? extends K, ? extends V> map) Copies every mapping in the specified Map to this Map.
V	remove(Object key) Removes a mapping with the specified key from this Map.
int	size() Returns the number of elements in this Map.
String	toString() Returns the string representation of this Map.
Collection<V>	values() Returns a collection of the values contained in this map.

From class java.lang.Object

Object	clone() Returns a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
boolean	equals(Object o) Compares the argument to the receiver, and returns true if they represent the same object using a class specific comparison.
void	finalize() Called by the virtual machine when there are no longer any (non-weak) references to the receiver.
final Class<? extends Object>	getClass() Returns the unique instance of java.lang.Class which represents the class of the receiver.
int	hashCode() Returns an integer hash code for the receiver.
final void	notify() Causes one thread which is `wait` ing on the receiver to be made ready to run.
final void	notifyAll() Causes all threads which are `wait` ing on the receiver to be made ready to run.
String	toString() Returns a string containing a concise, human-readable description of the receiver.
final void	wait(long time, int frac) Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by `notify` or `notifyAll`) or the expiration of the timeout.
final void	wait(long time) Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by `notify` or `notifyAll`) or the expiration of the timeout.
final void	wait() Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by `notify` or `notifyAll`).

From interface java.util.Map

abstract void	clear() Removes all elements from this Map, leaving it empty.
abstract boolean	containsKey(Object key) Searches this Map for the specified key.
abstract boolean	containsValue(Object value) Searches this Map for the specified value.
abstract Set<Entry<K, V>>	entrySet() Returns a `Set` whose elements comprise all of the mappings that are to be found in this `Map`.
abstract boolean	equals(Object object) Compares the argument to the receiver, and returns true if they represent the same object using a class specific comparison.
abstract V	get(Object key) Returns the value of the mapping with the specified key.
abstract int	hashCode() Returns an integer hash code for the receiver.
abstract boolean	isEmpty() Returns if this Map has no elements, a size of zero.
abstract Set<K>	keySet() Returns a Set of the keys contained in this Map.
abstract V	put(K key, V value) Maps the specified key to the specified value.
abstract void	putAll(Map<? extends K, ? extends V> map) Copies every mapping in the specified Map to this Map.
abstract V	remove(Object key) Removes a mapping with the specified key from this Map.
abstract int	size() Returns the number of elements in this Map.
abstract Collection<V>	values() Returns all of the current `Map` values in a `Collection`.

From interface java.util.SortedMap

Public Constructors

public TreeMap ()

Constructs a new empty instance of TreeMap.

public TreeMap (Comparator<? super K> comparator)

Constructs a new empty instance of TreeMap which uses the specified Comparator.

Parameters

comparator	the Comparator

public TreeMap (Map<? extends K, ? extends V> map)

Constructs a new instance of TreeMap containing the mappings from the specified Map and using the natural ordering.

Parameters

map	the mappings to add

Throws

ClassCastException	when a key in the Map does not implement the Comparable interface, or they keys in the Map cannot be compared

public TreeMap (SortedMap<K, ? extends V> map)

Constructs a new instance of TreeMap containing the mappings from the specified SortedMap and using the same Comparator.

Parameters

map	the mappings to add

Public Methods

public void clear ()

Removes all mappings from this TreeMap, leaving it empty.

public Object clone ()

Returns a new TreeMap with the same mappings, size and comparator as this TreeMap.

Returns

a shallow copy of this TreeMap

public Comparator<? super K> comparator ()

Returns the Comparator used to compare elements in this TreeMap.

Returns

a Comparator or null if the natural ordering is used

public boolean containsKey (Object key)

Searches this TreeMap for the specified key.

Parameters

key	the object to search for

Returns

true if key is a key of this TreeMap, false otherwise

Throws

ClassCastException	when the key cannot be compared with the keys in this TreeMap
NullPointerException	when the key is null and the comparator cannot handle null

public boolean containsValue (Object value)

Searches this TreeMap for the specified value.

Parameters

value	the object to search for

Returns

true if value is a value of this TreeMap, false otherwise

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

Returns a Set of the mappings contained in this TreeMap. Each element in the set is a Map.Entry. The set is backed by this TreeMap so changes to one are reflected by the other. The set does not support adding.

Returns

a Set of the mappings

public K firstKey ()

Answer the first sorted key in this TreeMap.

Returns

the first sorted key

Throws

NoSuchElementException	when this TreeMap is empty

public V get (Object key)

Returns the value of the mapping with the specified key.

Parameters

key	the key

Returns

the value of the mapping with the specified key

Throws

ClassCastException	when the key cannot be compared with the keys in this TreeMap
NullPointerException	when the key is null and the comparator cannot handle null

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

Returns a SortedMap of the specified portion of this TreeMap which contains keys less than the end key. The returned SortedMap is backed by this TreeMap so changes to one are reflected by the other.

Parameters

endKey	the end key

Returns

a sub-map where the keys are less than endKey

Throws

ClassCastException	when the end key cannot be compared with the keys in this TreeMap
NullPointerException	when the end key is null and the comparator cannot handle null

public Set<K> keySet ()

Returns a Set of the keys contained in this TreeMap. The set is backed by this TreeMap so changes to one are reflected by the other. The set does not support adding.

Returns

a Set of the keys

public K lastKey ()

Answer the last sorted key in this TreeMap.

Returns

the last sorted key

Throws

NoSuchElementException	when this TreeMap is empty

public V put (K key, V value)

Maps the specified key to the specified value.

Parameters

key	the key
value	the value

Returns

the value of any previous mapping with the specified key or null if there was no mapping

Throws

ClassCastException	when the key cannot be compared with the keys in this TreeMap
NullPointerException	when the key is null and the comparator cannot handle null

public void putAll (Map<? extends K, ? extends V> map)

Copies every mapping in the specified Map to this TreeMap.

Parameters

map	the Map to copy mappings from

Throws

ClassCastException	when a key in the Map cannot be compared with the keys in this TreeMap
NullPointerException	when a key in the Map is null and the comparator cannot handle null

public V remove (Object key)

Removes a mapping with the specified key from this TreeMap.

Parameters

key	the key of the mapping to remove

Returns

the value of the removed mapping or null if key is not a key in this TreeMap

Throws

ClassCastException	when the key cannot be compared with the keys in this TreeMap
NullPointerException	when the key is null and the comparator cannot handle null

public int size ()

Returns the number of mappings in this TreeMap.

Returns

the number of mappings in this TreeMap

public SortedMap<K, V> subMap (K startKey, K endKey)

Returns a SortedMap of the specified portion of this TreeMap which contains keys greater or equal to the start key but less than the end key. The returned SortedMap is backed by this TreeMap so changes to one are reflected by the other.

Parameters

startKey	the start key
endKey	the end key

Returns

a sub-map where the keys are greater or equal to startKey and less than endKey

Throws

ClassCastException	when the start or end key cannot be compared with the keys in this TreeMap
NullPointerException	when the start or end key is null and the comparator cannot handle null

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

Returns a SortedMap of the specified portion of this TreeMap which contains keys greater or equal to the start key. The returned SortedMap is backed by this TreeMap so changes to one are reflected by the other.

Parameters

startKey	the start key

Returns

a sub-map where the keys are greater or equal to startKey

Throws

ClassCastException	when the start key cannot be compared with the keys in this TreeMap
NullPointerException	when the start key is null and the comparator cannot handle null

public Collection<V> values ()

Returns a Collection of the values contained in this TreeMap. The collection is backed by this TreeMap so changes to one are reflected by the other. The collection does not support adding.

Returns

a Collection of the values

Jan	FEB	Mar
	18
2008	2009	2010

Interfaces

Classes

Enums

Exceptions

TreeMap

Class Overview

Summary

Public Constructors

public TreeMap ()

public TreeMap (Comparator<? super K> comparator)

Parameters

public TreeMap (Map<? extends K, ? extends V> map)

Parameters

Throws

public TreeMap (SortedMap<K, ? extends V> map)

Parameters

Public Methods

public void clear ()

See Also

public Object clone ()

Returns

See Also

public Comparator<? super K> comparator ()

Returns

public boolean containsKey (Object key)

Parameters

Returns

Throws

public boolean containsValue (Object value)

Parameters

Returns

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

Returns

public K firstKey ()

Returns

Throws

public V get (Object key)

Parameters

Returns

Throws

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

Parameters

Returns

Throws

public Set<K> keySet ()

Returns

public K lastKey ()

Returns

Throws

public V put (K key, V value)

Parameters

Returns

Throws

public void putAll (Map<? extends K, ? extends V> map)

Parameters

Throws

public V remove (Object key)

Parameters

Returns

Throws

public int size ()

Returns

public SortedMap<K, V> subMap (K startKey, K endKey)

Parameters

Returns

Throws

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

Parameters

Returns

Throws

public Collection<V> values ()

Returns