Module fr.dufrenoy.util

Package fr.dufrenoy.util

Class UnsynchronizedMultiMap<K,V>

java.lang.Object

fr.dufrenoy.util.UnsynchronizedMultiMap<K,V>

Type Parameters:

K - the type of keys at this level

V - the type of values at this level (may be another MultiMap)

All Implemented Interfaces:

MultiMap<K,V>, Serializable

public class UnsynchronizedMultiMap<K,V>
extends Object
implements MultiMap<K,V>, Serializable

A non-thread-safe implementation of MultiMap backed by a HashMap. Each UnsynchronizedMultiMap<K, V> associates keys of type K to values of type V, where V may itself be another MultiMap, enabling multi-level key hierarchies.

Iterators returned by the view methods (keySet(), values(), entrySet()) are fail-fast: if the map is structurally modified after the iterator is created, the iterator throws ConcurrentModificationException.

Null keys and null values are forbidden. All methods that accept keys or values throw NullPointerException if a null argument is passed.

This implementation is not thread-safe. For concurrent access, use SynchronizedMultiMap.

See Also:

MultiMap, SynchronizedMultiMap, Serialized Form

Constructor Summary

Constructors

Constructor	Description
UnsynchronizedMultiMap()	Creates a new empty UnsynchronizedMultiMap with default initial capacity.
UnsynchronizedMultiMap(int initialCapacity)	Creates a new empty UnsynchronizedMultiMap with the specified initial capacity.
UnsynchronizedMultiMap(MultiMap<? extends K,? extends V> source)	Creates a new UnsynchronizedMultiMap containing the same mappings as the specified MultiMap.
UnsynchronizedMultiMap(Map<? extends K,? extends V> source)	Creates a new UnsynchronizedMultiMap containing the same mappings as the specified map.

Method Summary

Modifier and Type	Method	Description
void	clear()	Removes all mappings from this map.
boolean	containsKey(K key)	Returns true if this map contains a mapping for the specified key.
Set<Map.Entry<K,V>>	entrySet()	Returns a Set view of the mappings contained in this map.
boolean	equals(Object obj)
V	get(K key)	Returns the value associated with the specified key, or null if no mapping exists.
Optional<V>	getOpt(K key)	Returns the value associated with the specified key wrapped in an Optional, or an empty Optional if no mapping exists.
V	getOrCreate(K key, Supplier<V> factory)	Returns the value associated with the specified key.
int	hashCode()
boolean	isEmpty()	Returns true if this map contains no mappings.
Set<K>	keySet()	Returns a Set view of the keys contained in this map.
V	put(K key, V value)	Associates the specified value with the specified key.
V	remove(K key)	Removes the mapping for the specified key, if present.
int	size()	Returns the number of key-value mappings at this level.
String	toString()
Collection<V>	values()	Returns a Collection view of the values contained in this map.

Methods inherited from class java.lang.Object

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

Constructor Detail

UnsynchronizedMultiMap

public UnsynchronizedMultiMap()

Creates a new empty UnsynchronizedMultiMap with default initial capacity.

UnsynchronizedMultiMap

public UnsynchronizedMultiMap(int initialCapacity)

Creates a new empty UnsynchronizedMultiMap with the specified initial capacity.

Parameters:

initialCapacity - the initial capacity

Throws:

IllegalArgumentException - if initialCapacity is negative

UnsynchronizedMultiMap

public UnsynchronizedMultiMap(Map<? extends K,? extends V> source)

Creates a new UnsynchronizedMultiMap containing the same mappings as the specified map. Null keys and null values in the source map cause a NullPointerException.

Parameters:

source - the map whose mappings are to be copied

Throws:

NullPointerException - if source is null, or if it contains null keys or null values

UnsynchronizedMultiMap

public UnsynchronizedMultiMap(MultiMap<? extends K,? extends V> source)

Creates a new UnsynchronizedMultiMap containing the same mappings as the specified MultiMap.

Parameters:

source - the multi-map whose mappings are to be copied

Throws:

NullPointerException - if source is null

Method Detail

get

public V get(K key)

Description copied from interface: MultiMap

Returns the value associated with the specified key, or null if no mapping exists. This method is designed for chained lookups across multiple levels.

Specified by:

get in interface MultiMap<K,V>

Parameters:

key - the key whose associated value is to be returned

Returns:

the value associated with key, or null

getOpt

public Optional<V> getOpt(K key)

Description copied from interface: MultiMap

Returns the value associated with the specified key wrapped in an Optional, or an empty Optional if no mapping exists.

Specified by:

getOpt in interface MultiMap<K,V>

Parameters:

key - the key whose associated value is to be returned

Returns:

an Optional containing the value, or empty

getOrCreate

public V getOrCreate(K key,
                     Supplier<V> factory)

Description copied from interface: MultiMap

Returns the value associated with the specified key. If no mapping exists, creates one using the given factory, inserts it, and returns the new value. This method is designed for chained writes across multiple levels.

Specified by:

getOrCreate in interface MultiMap<K,V>

Parameters:

key - the key whose associated value is to be returned or created

factory - the supplier used to create a new value if absent

Returns:

the existing or newly created value

containsKey

public boolean containsKey(K key)

Description copied from interface: MultiMap

Returns true if this map contains a mapping for the specified key.

Specified by:

containsKey in interface MultiMap<K,V>

Parameters:

key - the key whose presence is to be tested

Returns:

true if this map contains a mapping for key

put

public V put(K key,
             V value)

Description copied from interface: MultiMap

Associates the specified value with the specified key. If a mapping already exists for this key, the old value is replaced.

Specified by:

put in interface MultiMap<K,V>

Parameters:

key - the key with which the value is to be associated

value - the value to associate

Returns:

the previous value associated with key, or null if there was no mapping

remove

public V remove(K key)

Description copied from interface: MultiMap

Removes the mapping for the specified key, if present.

Specified by:

remove in interface MultiMap<K,V>

Parameters:

key - the key whose mapping is to be removed

Returns:

the previous value associated with key, or null if there was no mapping

clear

public void clear()

Description copied from interface: MultiMap

Removes all mappings from this map.

Specified by:

clear in interface MultiMap<K,V>

size

public int size()

Description copied from interface: MultiMap

Returns the number of key-value mappings at this level.

Specified by:

size in interface MultiMap<K,V>

Returns:

the number of mappings

isEmpty

public boolean isEmpty()

Description copied from interface: MultiMap

Returns true if this map contains no mappings.

Specified by:

isEmpty in interface MultiMap<K,V>

Returns:

true if empty

keySet

public Set<K> keySet()

Description copied from interface: MultiMap

Returns a Set view of the keys contained in this map.

Specified by:

keySet in interface MultiMap<K,V>

Returns:

a set view of the keys

values

public Collection<V> values()

Description copied from interface: MultiMap

Returns a Collection view of the values contained in this map.

Specified by:

values in interface MultiMap<K,V>

Returns:

a collection view of the values

entrySet

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

Description copied from interface: MultiMap

Returns a Set view of the mappings contained in this map. Each element is a Map.Entry<K, V>.

Specified by:

entrySet in interface MultiMap<K,V>

Returns:

a set view of the mappings

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object