1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * https://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19
20 package org.apache.commons.compress.utils;
21
22 import java.util.Collection;
23 import java.util.Iterator;
24 import java.util.Objects;
25
26 /**
27 * Iterator utilities.
28 *
29 * @since 1.13.
30 */
31 public class Iterators {
32
33 /**
34 * Adds all the elements in the source {@code iterator} to the target {@code collection}.
35 *
36 * <p>
37 * When this method returns, the {@code iterator} will be "empty": its {@code hasNext()} method returns {@code false}.
38 * </p>
39 *
40 * @param <T> type of the elements contained inside the collection
41 * @param collection target collection
42 * @param iterator source
43 * @return {@code true} if the target {@code collection} was modified as a result of this operation
44 */
45 public static <T> boolean addAll(final Collection<T> collection, final Iterator<? extends T> iterator) {
46 Objects.requireNonNull(collection);
47 Objects.requireNonNull(iterator);
48 boolean wasModified = false;
49 while (iterator.hasNext()) {
50 wasModified |= collection.add(iterator.next());
51 }
52 return wasModified;
53 }
54
55 private Iterators() {
56 // do not instantiate
57 }
58
59 }