org.dmfs.jems.optional.decorators

Class DelegatingOptional<T>

java.lang.Object

org.dmfs.jems.optional.decorators.DelegatingOptional<T>

All Implemented Interfaces:

Optional<T>

Direct Known Subclasses:

FirstPresent, NextPresent

public abstract class DelegatingOptional<T>
extends java.lang.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

Constructor and Description
DelegatingOptional(Optional<T> delegate)

Method Summary

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

DelegatingOptional

public DelegatingOptional(Optional<T> delegate)

Method Detail

isPresent

public final boolean isPresent()

Description copied from interface: Optional

Returns whether the optional value is present.

Specified by:

isPresent in interface Optional<T>

Returns:

true if the value is present, false otherwise.

value

public final T value()
              throws java.util.NoSuchElementException

Description copied from interface: Optional

Returns the optional value.

Specified by:

value in interface Optional<T>

Returns:

The value.

Throws:

java.util.NoSuchElementException - if the optional value is not present.