org.jjoost.collections
Interface Map<K,V>

All Superinterfaces:

AnyMap<K,V>, AnyReadMap<K,V>, Function<K,V>, java.io.Serializable

All Known Implementing Classes:

AdapterFromJDKMap, BiMapOneToMany, BiMapOneToOne, DefaultFactoryMap, DefaultFunctionMap, LockFreeHashMap, LockFreeLinkedHashMap, ScalarHashMap, SerialHashMap, SerialLinkedHashMap, SynchronizedMap

public interface Map<K,V>
extends AnyMap<K,V>, Function<K,V>

This interface declares a map that permits each key to map to at most one value

Author:

b.elliottsmith

Method Summary

Map<K,V>	copy() Returns a copy of the map.
V	ensureAndGet(K key, Factory<? extends V> putIfNotPresent) Equivalent to putIfAbsent(key, putIfNotPresent), except that instead of returning the value previously associated with the key, returns the value associated with the key as the method is exiting; i.e.
V	ensureAndGet(K key, Function<? super K,? extends V> putIfNotPresent) Equivalent to putIfAbsent(key, putIfNotPresent.create(key)), except that putIfNotPresent.create() is only executed if there is no key associated with the value.
Set<java.util.Map.Entry<K,V>>	entries() Returns a set representing all the key->value pairs in this map.
V	get(K key) A convenience method, equivalent to first(key)
Set<K>	keys() Returns a set representing all the keys in the domain of this map.
V	put(K key, V val) Ensures that the provided key binds to the provided value, removing and returning the value currently associated with the key, or null if none.
V	putIfAbsent(K key, Function<? super K,? extends V> putIfNotPresent) Equivalent to putIfAbsent(key, putIfNotPresent.create()), except that putIfNotPresent.create() is only executed if there is no key associated with the value.
V	putIfAbsent(K key, V val) Attempts to bind the provided key to the provided value.
int	size() A convenience method, equivalent to both totalCount() and uniqueKeyCount()
UnitarySet<V>	values(K key) Returns a set representing the values associated with the provided key in this map.

Methods inherited from interface org.jjoost.collections.AnyMap

add, clear, clearAndReturn, inverse, remove, remove, removeAndReturn, removeAndReturn, removeAndReturnFirst, shrink, values

Methods inherited from interface org.jjoost.collections.AnyReadMap

contains, contains, count, count, entries, first, isEmpty, list, permitsDuplicateKeys, totalCount, uniqueKeyCount

Methods inherited from interface org.jjoost.util.Function

apply

Method Detail

put

V put(K key,
      V val)

Ensures that the provided key binds to the provided value, removing and returning the value currently associated with the key, or null if none.

Specified by:

put in interface AnyMap<K,V>

Parameters:

key - the key

val - the val

Returns:

the value of any maplet removed as a result of this action

putIfAbsent

V putIfAbsent(K key,
              V val)

Attempts to bind the provided key to the provided value. If the key does not occur in the map then the value will be associated with it and null returned. If the key occurs in the map and is bound to a different value then this existing value will be returned

Specified by:

putIfAbsent in interface AnyMap<K,V>

Parameters:

key - the key

val - the val

Returns:

the value already associated with the key in the map, or null if none

putIfAbsent

V putIfAbsent(K key,
              Function<? super K,? extends V> putIfNotPresent)

Equivalent to putIfAbsent(key, putIfNotPresent.create()), except that putIfNotPresent.create() is only executed if there is no key associated with the value. In concurrent maps this is not a guarantee, but a best effort, as it is possible for another thread to set a value for the key after this has executed but before the record can be inserted.

Parameters:

key - the key

putIfNotPresent - the put if not present

Returns:

the value associated with the provided key pre method

ensureAndGet

V ensureAndGet(K key,
               Factory<? extends V> putIfNotPresent)

Equivalent to putIfAbsent(key, putIfNotPresent), except that instead of returning the value previously associated with the key, returns the value associated with the key as the method is exiting; i.e. if a new value is associated with the key as a result of this method, this new value will be returned, otherwise the existing value will be

Parameters:

key - the key

putIfNotPresent - the put if not present

Returns:

the value associated with the provided key post method

ensureAndGet

V ensureAndGet(K key,
               Function<? super K,? extends V> putIfNotPresent)

Equivalent to putIfAbsent(key, putIfNotPresent.create(key)), except that

1. putIfNotPresent.create() is only executed if there is no key associated with the value. In concurrent maps this is not a guarantee, but a best effort, as it is possible for another thread to set a value for the key after this has executed but before the record can be inserted
2. instead of returning the value previously associated with the key, returns the value associated with the key as the method is exiting; i.e. if a new value is associated with the key as a result of this method, this new value will be returned, otherwise the existing value will be

Parameters:

key - the key

putIfNotPresent - put if not present

Returns:

the value associated with the key post method

get

V get(K key)

A convenience method, equivalent to first(key)

Parameters:

key - the key

Returns:

the value associated with the key, or null if none

size

int size()

A convenience method, equivalent to both totalCount() and uniqueKeyCount()

Returns:

the int

values

UnitarySet<V> values(K key)

Description copied from interface: AnyReadMap

Returns a set representing the values associated with the provided key in this map. This set should always reflect changes to the map, and changes to the set should be reflected in the map also. Otherwise, this set should behave exactly as a regular set does.

Note that in a regular (scalar) map the set returned will be a UnitarySet, which contains at most one value. put() operations on such a set will override any existing value regardless of if it is equal to the one already present.

Specified by:

values in interface AnyMap<K,V>

Specified by:

values in interface AnyReadMap<K,V>

Returns:

the set of values mapped to by provided key

copy

Map<K,V> copy()

Description copied from interface: AnyMap

Returns a copy of the map. Note that this method may not necessarily return an object of the same class as the one it is called upon, but will return one indistinguishable from it with respect to all method calls.

Specified by:

copy in interface AnyMap<K,V>

Returns:

the any map< k, v>

entries

Set<java.util.Map.Entry<K,V>> entries()

Description copied from interface: AnyReadMap

Returns a set representing all the key->value pairs in this map. In a ListMap this will be a MultiSet. This set should always reflect changes to the map, and changes to the set should be reflected in the map also. Otherwise, this set should behave exactly as a regular set does.

Specified by:

entries in interface AnyMap<K,V>

Specified by:

entries in interface AnyReadMap<K,V>

Returns:

the entry set< k>

keys

Set<K> keys()

Description copied from interface: AnyReadMap

Returns a set representing all the keys in the domain of this map. In a MultiMap or ListMap this will be a MultiSet. This set should always reflect changes to the map, and changes to the set should be reflected in the map also. Otherwise, this set should behave exactly as a regular set does. The key equality used by this map can be obtained from this set.

Depending on the implementation of map, this key set may contain every occurrence of equal keys provided to the map, or may contain a subset thereof with repetitions to bring the number of occurrences in line with the number provided.

Note that the put() methods on this set will always fail, because no value can be provided to update the map with.

Specified by:

keys in interface AnyMap<K,V>

Specified by:

keys in interface AnyReadMap<K,V>

Returns:

the key set< k>