src/main/org/apache/tools/ant/util/StreamUtils.java

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */
package org.apache.tools.ant.util;

import java.util.Enumeration;
import java.util.Iterator;
import java.util.Spliterator;
import java.util.Spliterators;
import java.util.function.Consumer;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;

public class StreamUtils {
    /**
     * Turn Enumeration into a Stream
     *
     * @param <T> Enumeration type
     * @param e Enumeration
     * @return Stream
     */
    public static <T> Stream<T> enumerationAsStream(Enumeration<T> e) {
        return StreamSupport.stream(
                new Spliterators.AbstractSpliterator<T>(Long.MAX_VALUE, Spliterator.ORDERED) {
                    public boolean tryAdvance(Consumer<? super T> action) {
                        if (e.hasMoreElements()) {
                            action.accept(e.nextElement());
                            return true;
                        }
                        return false;
                    }
                    public void forEachRemaining(Consumer<? super T> action) {
                        while (e.hasMoreElements()) {
                            action.accept(e.nextElement());
                        }
                    }
                }, false);
    }

    /**
     * Turn Iterator into a Stream
     *
     * @param <T> Iterator type
     * @param i Iterator
     * @return Stream
     */
    public static <T> Stream<T> iteratorAsStream(Iterator<T> i) {
        return StreamSupport.stream(
                Spliterators.spliteratorUnknownSize(i, Spliterator.ORDERED),
                false);
    }
}