blob: bcbc9160ac5986a4454fdca802932af5e160c247 [file] [log] [blame]
Umesh Krishnaswamy345ee992012-12-13 20:29:48 -08001/**
2* Copyright 2012 Big Switch Networks, Inc.
3* Originally created by David Erickson, Stanford University
4*
5* Licensed under the Apache License, Version 2.0 (the "License"); you may
6* not use this file except in compliance with the License. You may obtain
7* a copy of the License at
8*
9* http://www.apache.org/licenses/LICENSE-2.0
10*
11* Unless required by applicable law or agreed to in writing, software
12* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
13* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
14* License for the specific language governing permissions and limitations
15* under the License.
16**/
17
18package net.floodlightcontroller.util;
19
20import java.util.Iterator;
21import java.util.NoSuchElementException;
22
23/**
24 * Iterator over all values in an iterator of iterators
25 *
26 * @param <T> the type of elements returned by this iterator
27 */
28public class MultiIterator<T> implements Iterator<T> {
29 Iterator<Iterator<T>> subIterator;
30 Iterator<T> current = null;
31
32 public MultiIterator(Iterator<Iterator<T>> subIterator) {
33 super();
34 this.subIterator = subIterator;
35 }
36
37 @Override
38 public boolean hasNext() {
39 if (current == null) {
40 if (subIterator.hasNext()) {
41 current = subIterator.next();
42 } else {
43 return false;
44 }
45 }
46 while (!current.hasNext() && subIterator.hasNext()) {
47 current = subIterator.next();
48 }
49
50 return current.hasNext();
51 }
52
53 @Override
54 public T next() {
55 if (hasNext())
56 return current.next();
57 throw new NoSuchElementException();
58 }
59
60 @Override
61 public void remove() {
62 if (hasNext())
63 current.remove();
64 throw new NoSuchElementException();
65 }
66}