Package org.dmfs.jems2.optional

Class DelegatingOptional<T>

java.lang.Object

org.dmfs.jems2.optional.DelegatingOptional<T>

All Implemented Interfaces:

Optional<T>

Direct Known Subclasses:

FirstPresent, MapCollapsed, NextPresent

public abstract class DelegatingOptional<T>
extends Object
implements Optional<T>

An abstract Optional which delegates all method calls to another given Optional.

This class is abstract and is meant to be a convenient way of composing Optionals despite the lack of native support for the decoration pattern in Java.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	DelegatingOptional(Optional<T> delegate)

Method Summary

Modifier and Type	Method	Description
final boolean	isPresent()	Returns whether the optional value is present.
final T	value()	Returns the optional value.

Methods inherited from class java.lang.Object

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

Constructor Details

DelegatingOptional

protected DelegatingOptional(Optional<T> delegate)

Method Details

isPresent

public final boolean isPresent()

Description copied from interface: Optional

Returns whether the optional value is present.

Specified by:

isPresent in interface Optional<T>

value

public final T value()
              throws NoSuchElementException

Description copied from interface: Optional

Returns the optional value.

Specified by:

value in interface Optional<T>

Throws:

NoSuchElementException - if the optional value is not present.