software.amazon.smithy.utils

Class OptionalUtils

java.lang.Object

software.amazon.smithy.utils.OptionalUtils

public final class OptionalUtils
extends java.lang.Object

Functions that make working with optionals easier.

Method Summary

Modifier and Type	Method and Description
static <T> void	ifPresentOrElse(java.util.Optional<T> value, java.util.function.Consumer<T> action, java.lang.Runnable emptyAction) Invokes a consumer if the Optional has a value, otherwise invoked a Runnable when the Optional is empty.
static <T> java.util.Optional<T>	or(java.util.Optional<T> value, java.util.function.Supplier<java.util.Optional<? extends T>> supplier) Retrieves the value of the optional if present or invokes the supplier for a value.
static <T> java.util.stream.Stream<T>	stream(java.util.Optional<T> value) Converts an Optional into a Stream that can be used in a flatmap.

Methods inherited from class java.lang.Object

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

Method Detail

or

public static <T> java.util.Optional<T> or(java.util.Optional<T> value,
                                           java.util.function.Supplier<java.util.Optional<? extends T>> supplier)

Retrieves the value of the optional if present or invokes the supplier for a value.

Type Parameters:

T - Type of value.

Parameters:

value - Value to check.

supplier - Supplier for a value if no value is present.

Returns:

A value of type T.

stream

public static <T> java.util.stream.Stream<T> stream(java.util.Optional<T> value)

Converts an Optional into a Stream that can be used in a flatmap.

This is a polyfill of Java 9's Optional#stream.

Type Parameters:

T - Value type.

Parameters:

value - Value to convert to a stream.

Returns:

A stream that contains a present value or a stream that is empty.

ifPresentOrElse

public static <T> void ifPresentOrElse(java.util.Optional<T> value,
                                       java.util.function.Consumer<T> action,
                                       java.lang.Runnable emptyAction)

Invokes a consumer if the Optional has a value, otherwise invoked a Runnable when the Optional is empty.

Type Parameters:

T - Type of value.

Parameters:

value - Value to check.

action - Action to invoke if a value is present.

emptyAction - Runnable to invoke if a value is not present.