Package org.apache.flink.util

Class LinkedOptionalMap<K,V>

java.lang.Object

org.apache.flink.util.LinkedOptionalMap<K,V>

@Internal
public final class LinkedOptionalMap<K,V>
extends Object

A LinkedOptionalMap is an order preserving map (like LinkedHashMap) where keys have a unique string name, but are optionally present, and the values are optional.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	LinkedOptionalMap.ConsumerWithException<K,V,E extends Throwable>	A Consumer that throws exceptions.
static class	LinkedOptionalMap.KeyValue<K,V>	Key-value pairs stored by the underlying map.
static class	LinkedOptionalMap.MergeResult<K,V>	The result of merging two LinkedOptionalMaps using mergeRightIntoLeft(LinkedOptionalMap, LinkedOptionalMap).

Constructor Summary

Constructors

Constructor	Description
LinkedOptionalMap()
LinkedOptionalMap(int initialSize)

Method Summary

Modifier and Type	Method	Description
Set<String>	absentKeysOrValues()	Returns the key names of any keys or values that are absent.
<E extends Throwable> void	forEach(LinkedOptionalMap.ConsumerWithException<K,V,E> consumer)
Set<LinkedOptionalMap.KeyValue<K,V>>	getPresentEntries()
boolean	hasAbsentKeysOrValues()	Checks whether there are entries with absent keys or values.
Set<String>	keyNames()	Returns the key names added to this map.
static <K,V> LinkedOptionalMap.MergeResult<K,V>	mergeRightIntoLeft(LinkedOptionalMap<K,V> left, LinkedOptionalMap<K,V> right)	Tries to merges the keys and the values of @right into @left.
static <K,V> LinkedOptionalMap<K,V>	optionalMapOf(Map<K,V> sourceMap, Function<K,String> keyNameGetter)	Creates an LinkedOptionalMap from the provided map.
void	put(String keyName, K key, V value)
int	size()
LinkedHashMap<K,V>	unwrapOptionals()	Assuming all the entries of this map are present (keys and values) this method would return a map with these key and values, stripped from their Optional wrappers.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LinkedOptionalMap

public LinkedOptionalMap()

LinkedOptionalMap

public LinkedOptionalMap(int initialSize)

Method Detail

optionalMapOf

public static <K,V> LinkedOptionalMap<K,V> optionalMapOf(Map<K,V> sourceMap,
                                                                     Function<K,String> keyNameGetter)

Creates an LinkedOptionalMap from the provided map.

This method is the equivalent of Optional.of(Object) but for maps. To support more than one NULL key, an optional map requires a unique string name to be associated with each key (provided by keyNameGetter)

Type Parameters:

K - key type

V - value type

Parameters:

sourceMap - a source map to wrap as an optional map.

keyNameGetter - function that assigns a unique name to the keys of the source map.

Returns:

an LinkedOptionalMap with optional named keys, and optional values.

mergeRightIntoLeft

public static <K,V> LinkedOptionalMap.MergeResult<K,V> mergeRightIntoLeft(LinkedOptionalMap<K,V> left,
                                                                                      LinkedOptionalMap<K,V> right)

Tries to merges the keys and the values of @right into @left.

size

public int size()

put

public void put(String keyName,
                @Nullable
                K key,
                @Nullable
                V value)

absentKeysOrValues

public Set<String> absentKeysOrValues()

Returns the key names of any keys or values that are absent.

hasAbsentKeysOrValues

public boolean hasAbsentKeysOrValues()

Checks whether there are entries with absent keys or values.

forEach

public <E extends Throwable> void forEach(LinkedOptionalMap.ConsumerWithException<K,V,E> consumer)
                                   throws E extends Throwable

Throws:

E extends Throwable

getPresentEntries

public Set<LinkedOptionalMap.KeyValue<K,V>> getPresentEntries()

unwrapOptionals

public LinkedHashMap<K,V> unwrapOptionals()

Assuming all the entries of this map are present (keys and values) this method would return a map with these key and values, stripped from their Optional wrappers. NOTE: please note that if any of the key or values are absent this method would throw an IllegalStateException.

keyNames

public Set<String> keyNames()

Returns the key names added to this map.