Class OptionalEnhancementExamples

java.lang.Object

net.jrodolfo.java_evolution.java09.OptionalEnhancementExamples

public class OptionalEnhancementExamples
extends Object

Demonstrates Optional methods added in Java 9.

Java 8 made missing return values explicit with Optional, but some common workflows still needed awkward code: trying a fallback lookup, handling present and missing branches together, and flattening many Optional values into a stream.

Java 9 added Optional.or(java.util.function.Supplier), Optional.ifPresentOrElse(java.util.function.Consumer, Runnable), and Optional.stream() to make those workflows direct.

Constructor Summary

Constructors

Constructor	Description
OptionalEnhancementExamples()

Method Summary

Modifier and Type	Method	Description
String	describe(Optional<String> value)	Uses Optional.ifPresentOrElse(java.util.function.Consumer, Runnable) to handle both branches explicitly.
Optional<String>	preferredEmail(Optional<String> primary, Optional<String> fallback)	Uses Optional.or(java.util.function.Supplier) to try a fallback Optional only when the primary Optional is empty.
List<String>	presentValues(List<Optional<String>> values)	Uses Optional.stream() to flatten Optionals into a stream pipeline.

Methods inherited from class Object

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

Constructor Details

OptionalEnhancementExamples

public OptionalEnhancementExamples()

Method Details

preferredEmail

public Optional<String> preferredEmail(Optional<String> primary,
 Optional<String> fallback)

Uses Optional.or(java.util.function.Supplier) to try a fallback Optional only when the primary Optional is empty.

Parameters:

primary - the preferred value

fallback - the fallback value

Returns:

the primary value when present, otherwise the fallback value

describe

public String describe(Optional<String> value)

Uses Optional.ifPresentOrElse(java.util.function.Consumer, Runnable) to handle both branches explicitly.

Parameters:

value - the Optional to describe

Returns:

text explaining whether the value was present

presentValues

public List<String> presentValues(List<Optional<String>> values)

Uses Optional.stream() to flatten Optionals into a stream pipeline.

Parameters:

values - the Optional values to collect

Returns:

only the values that are present