Modul de.sft.base

Package de.s42.base.functional

Klasse Either<FirstType,SecondType>

java.lang.Object

de.s42.base.functional.Either<FirstType,SecondType>

Typparameter:

FirstType - Type of the first value

SecondType - Type of the second value

public final class Either<FirstType,SecondType>
extends Object

Either is an implementation of the either monad. You can encode either 1 of 2 values (first, second) to be contained. It provides many powerful ways to interact with it.

Autor:

Benjamin Schiller

Feldübersicht

Felder

Modifizierer und Typ	Feld	Beschreibung
private final FirstType	first	Stores the first final.
private final SecondType	second	Stores the second final.

Konstruktorübersicht

Konstruktoren

Modifizierer	Konstruktor	Beschreibung
private	Either(FirstType first, SecondType second)	Internal constructor for an Either.

Methodenübersicht

Modifizierer und Typ	Methode	Beschreibung
void	either(Consumer<FirstType> actionFirst, Consumer<SecondType> actionSecond)	Calls on of the actions.
boolean	equals(Object obj)	Either is equal if first and second are equal.
Optional<FirstType>	first()	Returns a nullable Optional of first.
FirstType	firstOrElse(FirstType other)	Returns first if first is not null or other if first is null.
Object	firstOrSecond()	Returns either the first or the second value.
FirstType	firstOrThrow()	Returns a Optional of first or throws a exception if first is null.
int	hashCode()	The combined hashcode of first and second.
void	ifFirst(Consumer<FirstType> action)	Calls the action if first is not null with first as parameter.
void	ifSecond(Consumer<SecondType> action)	Calls the action if second is not null with second as parameter.
boolean	isFirst()	Returns true if first is not null.
boolean	isSecond()	Returns true if second is not null.
static <FirstType, SecondType> Either<FirstType,SecondType>	ofEither(FirstType first, SecondType second)	Create an Either with one of the given values being non null.
static <FirstType, SecondType> Either<FirstType,SecondType>	ofFirst(FirstType first)	Create an Either with first.
static <FirstType, SecondType> Either<FirstType,SecondType>	ofSecond(SecondType second)	Create an Either with second.
Optional<SecondType>	second()	Returns a nullable Optional of second.
SecondType	secondOrElse(SecondType other)	Returns second if second is not null or other if second is null.
SecondType	secondOrThrow()	Returns a Optional of second or throws a exception if second is null.
Stream<?>	stream()	Allows to get a stream either streaming first or second
String	toString()	Returns the first.toString() if first not null otherwise second.toString().

Von Klasse geerbte Methoden java.lang.Object

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

Felddetails

first

private final FirstType first

Stores the first final.

second

private final SecondType second

Stores the second final.

Konstruktordetails

Either

private Either(FirstType first,
 SecondType second)

Internal constructor for an Either.

Parameter:

first - First value

second - Second value

Methodendetails

ofEither

public static <FirstType,
SecondType>
Either<FirstType,SecondType> ofEither(FirstType first,
 SecondType second)
                               throws IllegalArgumentException

Create an Either with one of the given values being non null.

Typparameter:

FirstType - Type of the first value

SecondType - Type of the second value

Parameter:

first - First value

second - Second value

Gibt zurück:

Either of type <FirstType, SecondType>

Löst aus:

IllegalArgumentException - if both or none is null (first != null ^ second != null)

ofFirst

public static <FirstType,
SecondType>
Either<FirstType,SecondType> ofFirst(FirstType first)
                              throws NullPointerException

Create an Either with first.

Typparameter:

FirstType - Type of the first value

SecondType - Type of the second value

Parameter:

first - First value

Gibt zurück:

An Either of first value

Löst aus:

NullPointerException - if first is null

ofSecond

public static <FirstType,
SecondType>
Either<FirstType,SecondType> ofSecond(SecondType second)
                               throws NullPointerException

Create an Either with second.

Typparameter:

FirstType - Type of the first value

SecondType - Type of the second value

Parameter:

second - Second value

Gibt zurück:

An Either of second value

Löst aus:

NullPointerException - if second is null

ifFirst

public void ifFirst(Consumer<FirstType> action)

Calls the action if first is not null with first as parameter.

Parameter:

action - Called if first is not null

ifSecond

public void ifSecond(Consumer<SecondType> action)

Calls the action if second is not null with second as parameter.

Parameter:

action - Called if second is not null

either

public void either(Consumer<FirstType> actionFirst,
 Consumer<SecondType> actionSecond)

Calls on of the actions. Either actionFirst with first as parameter if first is not null or actionSecond with second as parameter.

Parameter:

actionFirst - Called if first is not null

actionSecond - Called if second is not null

isFirst

public boolean isFirst()

Returns true if first is not null.

Gibt zurück:

True if first is not null

isSecond

public boolean isSecond()

Returns true if second is not null.

Gibt zurück:

True if second is not null

first

public Optional<FirstType> first()

Returns a nullable Optional of first.

Gibt zurück:

A nullable Optional of first

firstOrThrow

public FirstType firstOrThrow()
                       throws NullPointerException

Returns a Optional of first or throws a exception if first is null.

Gibt zurück:

Optional of first or throws a exception if first is null

Löst aus:

NullPointerException - If first is null

firstOrElse

public FirstType firstOrElse(FirstType other)

Returns first if first is not null or other if first is null.

Parameter:

other - Value that will be returned if first is null

Gibt zurück:

first if first is not null or other if first is null

second

public Optional<SecondType> second()

Returns a nullable Optional of second.

Gibt zurück:

A nullable Optional of second

secondOrThrow

public SecondType secondOrThrow()
                         throws NullPointerException

Returns a Optional of second or throws a exception if second is null.

Gibt zurück:

Optional of second or throws a exception if second is null

Löst aus:

NullPointerException - If second is null

secondOrElse

public SecondType secondOrElse(SecondType other)

Returns second if second is not null or other if second is null.

Parameter:

other - Value that will be returned if second is null

Gibt zurück:

Second if second is not null or other if second is null

firstOrSecond

public Object firstOrSecond()

Returns either the first or the second value. Allows to unwrap easily.

Gibt zurück:

The first if not null or second

stream

public Stream<?> stream()

Allows to get a stream either streaming first or second

Gibt zurück:

A stream that either streams first or second

toString

public String toString()

Returns the first.toString() if first not null otherwise second.toString().

Setzt außer Kraft:

toString in Klasse Object

Gibt zurück:

String Of either first of second

hashCode

public int hashCode()

The combined hashcode of first and second.

Setzt außer Kraft:

hashCode in Klasse Object

Gibt zurück:

Combined hashcode of first and second

equals

public boolean equals(Object obj)

Either is equal if first and second are equal.

Setzt außer Kraft:

equals in Klasse Object

Parameter:

obj - Other Either

Gibt zurück:

True if first and second are equal