1 /*
2 * Copyright 2012 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the License. You may obtain a copy of the License at:
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package io.netty.channel.group;
17
18 import java.util.Iterator;
19 import java.util.NoSuchElementException;
20
21 /**
22 */
23 final class CombinedIterator<E> implements Iterator<E> {
24
25 private final Iterator<E> i1;
26 private final Iterator<E> i2;
27 private Iterator<E> currentIterator;
28
29 CombinedIterator(Iterator<E> i1, Iterator<E> i2) {
30 if (i1 == null) {
31 throw new NullPointerException("i1");
32 }
33 if (i2 == null) {
34 throw new NullPointerException("i2");
35 }
36 this.i1 = i1;
37 this.i2 = i2;
38 currentIterator = i1;
39 }
40
41 @Override
42 public boolean hasNext() {
43 for (;;) {
44 if (currentIterator.hasNext()) {
45 return true;
46 }
47
48 if (currentIterator == i1) {
49 currentIterator = i2;
50 } else {
51 return false;
52 }
53 }
54 }
55
56 @Override
57 public E next() {
58 for (;;) {
59 try {
60 return currentIterator.next();
61 } catch (NoSuchElementException e) {
62 if (currentIterator == i1) {
63 currentIterator = i2;
64 } else {
65 throw e;
66 }
67 }
68 }
69 }
70
71 @Override
72 public void remove() {
73 currentIterator.remove();
74 }
75
76 }