com.gemalto.idp.mobile.qr.emv

Class OptionalDO<T>

java.lang.Object

com.gemalto.idp.mobile.qr.emv.OptionalDO<T>

public final class OptionalDO<T>
extends Object

Subset implementation of Optional class from Java 8

Since:

5.0

Method Summary

Modifier and Type	Method and Description
static <T> OptionalDO<T>	empty() Returns an empty OptionalDO instance.
T	get() Returns the value if present, otherwise throws NoSuchElementException.
boolean	isPresent() Returns true if present, otherwise false.
static <T> OptionalDO<T>	of(T value) Returns an OptionalDO describing the given non-null value.
static <T> OptionalDO<T>	ofNullable(T value) Returns an OptionalDO describing the given value, if non-null, otherwise returns an empty OptionalDO.
T	orElse(T other) Returns the value if present, otherwise returns other.

Methods inherited from class java.lang.Object

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

Method Detail

empty

public static <T> OptionalDO<T> empty()

Returns an empty OptionalDO instance. No value is present for this OptionalDO.

Type Parameters:

T - The type of the non-existent value

Returns:

an empty OptionalDO

of

public static <T> OptionalDO<T> of(T value)

Returns an OptionalDO describing the given non-null value.

Type Parameters:

T - the type of the value

Parameters:

value - the value to describe, which must be non-null

Returns:

an OptionalDO with the value present

Throws:

NullPointerException - if value is null

ofNullable

public static <T> OptionalDO<T> ofNullable(T value)

Returns an OptionalDO describing the given value, if non-null, otherwise returns an empty OptionalDO.

Type Parameters:

T - the type of the value

Parameters:

value - the possibly-null value to describe

Returns:

an OptionalDO with a present value if the specified value is non-null, otherwise an empty OptionalDO

get

public T get()

Returns the value if present, otherwise throws NoSuchElementException.

Returns:

the non-null value described by this OptionalDO

Throws:

NoSuchElementException - if no value is present

See Also:

isPresent()

isPresent

public boolean isPresent()

Returns true if present, otherwise false.

Returns:

true if a value is present, otherwise false

orElse

public T orElse(T other)

Returns the value if present, otherwise returns other.

Parameters:

other - the value to be returned, if no value is present. May be null.

Returns:

the value, if present, otherwise other