sirius.kernel.commons

Class Tuple<F,S>

java.lang.Object

sirius.kernel.commons.Tuple<F,S>

Type Parameters:

F - defines the first type of the tuple

S - defines the second type of the tuple

Direct Known Subclasses:

ComparableTuple

public class Tuple<F,S>
extends Object

Represents a tuple of two values with two arbitrary types.

If the first type is comparable and should be used to compare the tuples, ComparableTuple can be used.

See Also:

Tuple, Comparable

Constructor Summary

Constructors

Constructor and Description
Tuple(F first, S second) Creates a tuple with a givens value for first and second Can be used to specify the generic types for F and S.

Method Summary

Modifier and Type	Method and Description
static <F,S> Tuple<F,S>	create() Creates a new tuple with both values set to null
static <F,S> Tuple<F,S>	create(F first) Creates a tuple with a given value for first
static <F,S> Tuple<F,S>	create(F first, S second) Creates a tuple with a givens value for first and second
boolean	equals(Object obj)
static <T extends Tuple<K,V>,K,V> List<K>	firsts(Collection<T> tuples) Extracts all first components of the given collection of tuples and returns them as list.
static <K,V> Stream<Tuple<K,V>>	flatten(Map.Entry<K,Collection<V>> entry) Maps an entry which contains a collection as value into a Stream of tuples, containing the key of the entry along with a value of the collection.
static <K,V> List<Tuple<K,V>>	fromMap(Map<K,V> map) Converts a map into a list of tuples.
F	getFirst() Returns the first component of the tuple
S	getSecond() Returns the second component of the tuple
int	hashCode()
static <T extends Tuple<K,V>,K,V> List<V>	seconds(Collection<T> tuples) Extracts all second components of the given collection of tuples and returns them as list.
void	setFirst(F first) Sets the first component of the tuple to the given value.
void	setSecond(S second) Sets the second component of the tuple to the given value.
static <K,V> Map<K,V>	toMap(Collection<Tuple<K,V>> values) Converts a collection of tuples into a map
static <K,V> Collector<Tuple<K,V>,Map<K,V>,Map<K,V>>	toMap(Supplier<Map<K,V>> supplier) Provides a Collector which can be used to collect a Stream of tuples into a Map.
static <K,V> Collector<Tuple<K,V>,Map<K,V>,Map<K,V>>	toMap(Supplier<Map<K,V>> supplier, BinaryOperator<V> merger) Provides a Collector which can be used to collect a Stream of tuples into a Map.
static <K,V> Collector<Tuple<K,V>,MultiMap<K,V>,MultiMap<K,V>>	toMultiMap(Supplier<MultiMap<K,V>> supplier) Provides a Collector which can be used to collect a Stream of tuples into a MultiMap.
String	toString()
static <K,V> Tuple<K,V>	valueOf(Map.Entry<K,V> entry) Converts a Map.Entry into a tuple.

Methods inherited from class java.lang.Object

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

Constructor Detail

Tuple

public Tuple(F first,
             S second)

Creates a tuple with a givens value for first and second

Can be used to specify the generic types for F and S. Otherwise, the create methods can be used.

Parameters:

first - defines the value to be used for the first component of the tuple

second - defines the value to be used for the second component of the tuple

Method Detail

create

public static <F,S> Tuple<F,S> create()

Creates a new tuple with both values set to null

Type Parameters:

F - defines the first type of the tuple

S - defines the second type of the tuple

Returns:

the newly created tuple

create

public static <F,S> Tuple<F,S> create(F first)

Creates a tuple with a given value for first

Type Parameters:

F - defines the first type of the tuple

S - defines the second type of the tuple

Parameters:

first - defines the value to be used for the first component of the tuple

Returns:

the newly created tuple

create

public static <F,S> Tuple<F,S> create(F first,
                                      S second)

Creates a tuple with a givens value for first and second

Type Parameters:

F - defines the first type of the tuple

S - defines the second type of the tuple

Parameters:

first - defines the value to be used for the first component of the tuple

second - defines the value to be used for the second component of the tuple

Returns:

the newly created tuple

getFirst

public F getFirst()

Returns the first component of the tuple

Returns:

the first component of the tuple

setFirst

public void setFirst(F first)

Sets the first component of the tuple to the given value.

Parameters:

first - defines the value to be used as the first component of the tuple

getSecond

public S getSecond()

Returns the second component of the tuple

Returns:

the second component of the tuple

setSecond

public void setSecond(S second)

Sets the second component of the tuple to the given value.

Parameters:

second - defines the value to be used as the second component of the tuple

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

firsts

public static <T extends Tuple<K,V>,K,V> List<K> firsts(@Nonnull
                                                        Collection<T> tuples)

Extracts all first components of the given collection of tuples and returns them as list.

Type Parameters:

T - the type of the tuples involved

K - the type of the first elements of the tuples

V - the type of the second elements of the tuples

Parameters:

tuples - the collection of tuples to process

Returns:

a list containing each first component of the collection of given tuples.

seconds

public static <T extends Tuple<K,V>,K,V> List<V> seconds(@Nonnull
                                                         Collection<T> tuples)

Extracts all second components of the given collection of tuples and returns them as list.

Type Parameters:

T - the type of the tuples involved

K - the type of the first elements of the tuples

V - the type of the second elements of the tuples

Parameters:

tuples - the collection of tuples to process

Returns:

a list containing each second component of the collection of given tuples.

fromMap

public static <K,V> List<Tuple<K,V>> fromMap(@Nonnull
                                             Map<K,V> map)

Converts a map into a list of tuples.

Type Parameters:

K - the key type of the map and therefore the type of the first component of the tuples

V - the value type of the map and therefore the type of the second component of the tuples

Parameters:

map - the map to be converted

Returns:

a list of tuples, containing one tuple per map entry where the first component is the key, and the second component is the value of the map entry.

toMap

public static <K,V> Map<K,V> toMap(@Nonnull
                                   Collection<Tuple<K,V>> values)

Converts a collection of tuples into a map

Type Parameters:

K - the key type of the map and therefore the type of the first component of the tuples

V - the value type of the map and therefore the type of the second component of the tuples

Parameters:

values - the collection of tuples to be converted

Returns:

a map containing an entry for each tuple in the collection, where the key is the first component of the tuple and the value is the second component of the tuple. If two tuples have equal values as first component, the specific map entry will be overridden in the order defined in the given collection.

toMap

public static <K,V> Collector<Tuple<K,V>,Map<K,V>,Map<K,V>> toMap(Supplier<Map<K,V>> supplier,
                                                                  BinaryOperator<V> merger)

Provides a Collector which can be used to collect a Stream of tuples into a Map.

As an example: aStream.collect(Tuple.toMap(HashMap::new, (a, b) -> b)) will transform the stream of tuples into a map where a later key value pair will overwrite earlier ones.

Type Parameters:

K - key type of the tuples being processed

V - value type of the tuples being processed

Parameters:

supplier - factory for generating the result map

merger - used to decide which value to keep on a key collision

Returns:

a Collector which transforms a stream of tuples into a map

See Also:

toMap(java.util.function.Supplier)

toMap

public static <K,V> Collector<Tuple<K,V>,Map<K,V>,Map<K,V>> toMap(Supplier<Map<K,V>> supplier)

Provides a Collector which can be used to collect a Stream of tuples into a Map.

Key collisions are automatically handled by choosing the later entry (updating the map).

Type Parameters:

K - key type of the tuples being processed

V - value type of the tuples being processed

Parameters:

supplier - factory for generating the result map

Returns:

a Collector which transforms a stream of tuples into a map

toMultiMap

public static <K,V> Collector<Tuple<K,V>,MultiMap<K,V>,MultiMap<K,V>> toMultiMap(Supplier<MultiMap<K,V>> supplier)

Provides a Collector which can be used to collect a Stream of tuples into a MultiMap.

The type of MultiMap used can be determined by the supplier. So for example MultiMap::createOrdered will create a map with ordered keys.

Type Parameters:

K - key type of the tuples being processed

V - value type of the tuples being processed

Parameters:

supplier - factory for generating the result map

Returns:

a Collector which transforms a stream of tuples into a multi map

flatten

public static <K,V> Stream<Tuple<K,V>> flatten(Map.Entry<K,Collection<V>> entry)

Maps an entry which contains a collection as value into a Stream of tuples, containing the key of the entry along with a value of the collection.

This method is designed to be used with Stream.flatMap(java.util.function.Function):

 
      map.entrySet().flatMap(e -> Tuple.flatten(e)).forEach(t -> System.out.println(t));
 
 

Type Parameters:

K - the key type of the entry

V - the value type of the entry

Parameters:

entry - the entry to transform

Returns:

a Stream of tuples representing the original entry

valueOf

public static <K,V> Tuple<K,V> valueOf(Map.Entry<K,V> entry)

Converts a Map.Entry into a tuple.

Type Parameters:

K - the key type of the entry

V - the value type of the entry

Parameters:

entry - the entry to convert

Returns:

a tuple containing the key as first and the value as second parameter