/** Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved. Contact: SYSTAP, LLC DBA Blazegraph 2501 Calvert ST NW #106 Washington, DC 20008 [email protected] This program 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; version 2 of the License. This program 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 this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ package com.blazegraph.gremlin.util; import java.util.Iterator; import java.util.Spliterator; import java.util.Spliterators; import java.util.stream.Stream; import java.util.stream.StreamSupport; /** * Additional Java 8 stream helpers. * * @author mikepersonick */ public class Streams { /** * <p> * Obtain a Java 8 stream from an iterator. If the iterator happens to * implement AutoCloseable (e.g. {@link CloseableIterator}), the stream's * onClose behavior will close the iterator. Thus it is important to * always close the returned stream, or use within a try-with-resources: * </p> * <pre> * {@code * try (Stream<Object> s = Streams.of(it)) { * // do something with s * } // auto-close * } * </pre> * */ public static final <T> Stream<T> of(final Iterator<T> it) { final Stream<T> s = StreamSupport.stream( Spliterators.spliteratorUnknownSize(it, Spliterator.ORDERED), false); if (it instanceof AutoCloseable) { final AutoCloseable closeable = (AutoCloseable) it; s.onClose(() -> Code.wrapThrow(() -> closeable.close())); } return s; } }