Package com.github.mizool.core

Class Optionals

java.lang.Object

com.github.mizool.core.Optionals

public final class Optionals
extends Object

Method Summary

Modifier and Type	Method	Description
static <T> Stream<T>	streamPresentValue(@NonNull Optional<T> optional)	Used in streams to flat-map each Optional to its value if present. This method is intended to be used as follows:
static <T> Function<Optional<T>,T>	unwrapRequiredObject(@NonNull Class<T> classOfT)	Used when an object can be reasonably expected to exist, resulting in a DataInconsistencyException if it does not exist.
static <T> T	unwrapRequiredObject(@NonNull Optional<T> wrapped, @NonNull Class<T> classOfT)	Used when an object can be reasonably expected to exist, resulting in a DataInconsistencyException if it does not exist.
static <T> Function<Optional<T>,T>	unwrapUserMentionedObject(@NonNull Class<T> classOfT)	Used when a user-submitted entity refers to another object, resulting in a UnprocessableEntityException if that object does not exist.
static <T> T	unwrapUserMentionedObject(@NonNull Optional<T> wrapped, @NonNull Class<T> classOfT)	Used when a user-submitted entity refers to another object, resulting in a UnprocessableEntityException if that object does not exist.
static <T> Function<Optional<T>,T>	unwrapUserRequestedObject(@NonNull Class<T> classOfT)	Used when a user directly requests an object, resulting in an ObjectNotFoundException if it does not exist.
static <T> T	unwrapUserRequestedObject(@NonNull Optional<T> wrapped, @NonNull Class<T> classOfT)	Used when a user directly requests an object, resulting in an ObjectNotFoundException if it does not exist.

Methods inherited from class java.lang.Object

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

Method Details

unwrapUserRequestedObject

public static <T> T unwrapUserRequestedObject(@NonNull
 @NonNull Optional<T> wrapped,
 @NonNull
 @NonNull Class<T> classOfT)

Used when a user directly requests an object, resulting in an ObjectNotFoundException if it does not exist.

unwrapUserRequestedObject

public static <T> Function<Optional<T>,T> unwrapUserRequestedObject(@NonNull
 @NonNull Class<T> classOfT)

Used when a user directly requests an object, resulting in an ObjectNotFoundException if it does not exist.

unwrapRequiredObject

public static <T> T unwrapRequiredObject(@NonNull
 @NonNull Optional<T> wrapped,
 @NonNull
 @NonNull Class<T> classOfT)

Used when an object can be reasonably expected to exist, resulting in a DataInconsistencyException if it does not exist.

unwrapRequiredObject

public static <T> Function<Optional<T>,T> unwrapRequiredObject(@NonNull
 @NonNull Class<T> classOfT)

Used when an object can be reasonably expected to exist, resulting in a DataInconsistencyException if it does not exist.

unwrapUserMentionedObject

public static <T> T unwrapUserMentionedObject(@NonNull
 @NonNull Optional<T> wrapped,
 @NonNull
 @NonNull Class<T> classOfT)

Used when a user-submitted entity refers to another object, resulting in a UnprocessableEntityException if that object does not exist.

unwrapUserMentionedObject

public static <T> Function<Optional<T>,T> unwrapUserMentionedObject(@NonNull
 @NonNull Class<T> classOfT)

Used when a user-submitted entity refers to another object, resulting in a UnprocessableEntityException if that object does not exist.

streamPresentValue

public static <T> Stream<T> streamPresentValue(@NonNull
 @NonNull Optional<T> optional)

Used in streams to flat-map each Optional to its value if present.

This method is intended to be used as follows:

     .flatMap(Optionals::streamPresentValue)
 

Using this method is equivalent of chaining Optional.isPresent() and Optional.get() like this:

     .filter(Optional::isPresent)
     .map(Optional::get)