1 /*
2 * Copyright 2009 Red Hat, Inc.
3 *
4 * Red Hat licenses this file to you under the Apache License, version 2.0
5 * (the "License"); you may not use this file except in compliance with the
6 * 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 org.jboss.netty.channel.group;
17
18 import java.util.Iterator;
19 import java.util.NoSuchElementException;
20
21 /**
22 * @author <a href="http://www.jboss.org/netty/">The Netty Project</a>
23 * @author <a href="http://gleamynode.net/">Trustin Lee</a>
24 * @version $Rev: 2080 $, $Date: 2010-01-26 18:04:19 +0900 (Tue, 26 Jan 2010) $
25 */
26 final class CombinedIterator<E> implements Iterator<E> {
27
28 private final Iterator<E> i1;
29 private final Iterator<E> i2;
30 private Iterator<E> currentIterator;
31
32 CombinedIterator(Iterator<E> i1, Iterator<E> i2) {
33 if (i1 == null) {
34 throw new NullPointerException("i1");
35 }
36 if (i2 == null) {
37 throw new NullPointerException("i2");
38 }
39 this.i1 = i1;
40 this.i2 = i2;
41 currentIterator = i1;
42 }
43
44 public boolean hasNext() {
45 boolean hasNext = currentIterator.hasNext();
46 if (hasNext) {
47 return true;
48 }
49
50 if (currentIterator == i1) {
51 currentIterator = i2;
52 return hasNext();
53 } else {
54 return false;
55 }
56 }
57
58 public E next() {
59 try {
60 E e = currentIterator.next();
61 return e;
62 } catch (NoSuchElementException e) {
63 if (currentIterator == i1) {
64 currentIterator = i2;
65 return next();
66 } else {
67 throw e;
68 }
69 }
70 }
71
72 public void remove() {
73 currentIterator.remove();
74 }
75
76 }