Java Stream Operation optionalToStream(Optional optional)

Description

optional To Stream

License

Open Source License

Parameter

Parameter	Description
optional	the optional to change into a stream
T	the type in the optional

Return

a stream of one item if the optional has an element, else an empty stream

Declaration

public static <T> Stream<T> optionalToStream(Optional<T> optional) 

Method Source Code

//package com.java2s;
/*//from w w  w .  j ava2  s .c om
 * Grakn - A Distributed Semantic Database
 * Copyright (C) 2016  Grakn Labs Limited
 *
 * Grakn is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Grakn is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Grakn. If not, see <http://www.gnu.org/licenses/gpl.txt>.
 */

import java.util.Optional;

import java.util.stream.Stream;

public class Main {
    /**
     * @param optional the optional to change into a stream
     * @param <T> the type in the optional
     * @return a stream of one item if the optional has an element, else an empty stream
     */
    public static <T> Stream<T> optionalToStream(Optional<T> optional) {
        return optional.map(Stream::of).orElseGet(Stream::empty);
    }
}

Related

1. mkString(Stream items, String prefix, String delimiter, String suffix)
2. nullableStreamOf(Collection nullableCollection)
3. ofType(Stream stream, Class type)
4. opt2stream(Optional opt)
5. optionalToStream(final Optional optional)
6. orStream(Stream> stream)
7. parallelStreamFromIterable(Iterable in)
8. prepend(final T first, final Stream rest)
9. rangeStream(int n, boolean parallel)