de.saxsys.synchronizefx.core.metamodel

Class Optional<T>

java.lang.Object

de.saxsys.synchronizefx.core.metamodel.Optional<T>

Type Parameters:

T - The type that may is present or not

public final class Optional<T>
extends Object

A container which holds a non-null value or not.

This class is designed after the java.util.Optional class of Java 8 and intended to be replaced with it when Java 7 support is dropped.

Author:

Raik Bieniek

Method Summary

Methods

Modifier and Type	Method and Description
static <T> Optional<T>	empty() Creates an Optional that has no value.
T	get() The value of this Optional.
boolean	isPresent() Checks if this optional has a value or not.
static <T> Optional<T>	of(T value) Creates an Optional that wraps a given non-null value.
static <T> Optional<T>	ofNullable(T value) Creates an Optional that wraps a given non-null value or null.

Methods inherited from class java.lang.Object

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

Method Detail

isPresent

public boolean isPresent()

Checks if this optional has a value or not.

Returns:

true if it has, false if not.

get

public T get()
      throws NoSuchElementException

The value of this Optional.

Returns:

The value

Throws:

NoSuchElementException - if this Optional has no value.

empty

public static <T> Optional<T> empty()

Creates an Optional that has no value.

Type Parameters:

T - the type of the value of the Optional would have if it would not be null.

Returns:

The Optional created.

of

public static <T> Optional<T> of(T value)
                      throws NullPointerException

Creates an Optional that wraps a given non-null value.

Type Parameters:

T - The type of the wrapped value.

Parameters:

value - The value to wrap.

Returns:

The optional created.

Throws:

NullPointerException - if the passed value was null.

ofNullable

public static <T> Optional<T> ofNullable(T value)

Creates an Optional that wraps a given non-null value or null.

Type Parameters:

T - The type of the wrapped value.

Parameters:

value - The value that should be wrapped or null.

Returns:

The created Optional.