oracle.dbtools.plugin.api.collections

Interface MultiMap<K,V>

Type Parameters:

K - the type of keys maintained by this multimap

V - the type of mapped values

public interface MultiMap<K,V>

A MultiMap is like a Map except that a key can be bound to multiple values. It is similar to Map<K,Collection<V>>, but not identical because in a multimap, each key and value is stored as an individual entry. This means that the iteration order and size() will be different. If you actually need the Map<K,Collection<V>> semantics, then call the map() method.

Author:

cdivilly

See Also:

size()

Method Summary

Modifier and Type	Method and Description
default boolean	containsKey(Object key) Test if this object contains the specified key.
Collection<Map.Entry<K,V>>	entries() Get each key value pair in this multi-map.
default V	get(Object key) Get the first value associated with the specified key.
default boolean	isEmpty() Returns true if this MultiMap contains no key-value mappings.
default Set<K>	keySet() The set of keys in this object
Map<K,Collection<V>>	map() Represent this MultiMap as a Map<K,Collection<V>> data structure, where values are grouped by key.
default int	size() The number of entries in this MultiMap.
Collection<V>	values(Object key) Get all the values associated with the specified key.

Method Detail

containsKey

default boolean containsKey(Object key)

Test if this object contains the specified key.

Parameters:

key - The key to search for

Returns:

true if the key exists, false otherwise

entries

Collection<Map.Entry<K,V>> entries()

Get each key value pair in this multi-map.

Returns:

Collection of all Map.Entrys in this multi map.

get

default V get(Object key)

Get the first value associated with the specified key.

Parameters:

key - The key to search for

Returns:

The first value associated with the key, or null if no values are associated with the key

isEmpty

default boolean isEmpty()

Returns true if this MultiMap contains no key-value mappings.

Returns:

true if this MultiMap contains no key-value mappings

keySet

default Set<K> keySet()

The set of keys in this object

Returns:

The key set

map

Map<K,Collection<V>> map()

Represent this MultiMap as a Map<K,Collection<V>> data structure, where values are grouped by key.

Returns:

Map instance

size

default int size()

The number of entries in this MultiMap. Note that this method returns the number of entries, not the number of keys as a Map would. Consider the following MultiMap

 { a = b, c = d, a = e }
 

The size() of this MultiMap is 3. Note that the Map.size() value returned by the Map instance returned from the map() method would be 2, because there are only two distinct keys.

Returns:

the number of values in the multimap

values

Collection<V> values(Object key)

Get all the values associated with the specified key.

Parameters:

key - The name of the key

Returns:

The values associated with the key, or returns null if the key is not present in the MultiMap