Shuyi Chen | d7955ce | 2013-05-22 14:51:55 -0700 | [diff] [blame] | 1 | // GenericsNote: Converted. |
| 2 | /* |
| 3 | * Copyright 2004 The Apache Software Foundation |
| 4 | * |
| 5 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | * you may not use this file except in compliance with the License. |
| 7 | * You may obtain 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, |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | * See the License for the specific language governing permissions and |
| 15 | * limitations under the License. |
| 16 | */ |
| 17 | package org.jivesoftware.smack.util.collections; |
| 18 | |
| 19 | import java.util.NoSuchElementException; |
| 20 | |
| 21 | /** |
| 22 | * Provides an implementation of an empty iterator. |
| 23 | * |
| 24 | * @author Matt Hall, John Watkinson, Stephen Colebourne |
| 25 | * @version $Revision: 1.1 $ $Date: 2005/10/11 17:05:24 $ |
| 26 | * @since Commons Collections 3.1 |
| 27 | */ |
| 28 | abstract class AbstractEmptyIterator <E> { |
| 29 | |
| 30 | /** |
| 31 | * Constructor. |
| 32 | */ |
| 33 | protected AbstractEmptyIterator() { |
| 34 | super(); |
| 35 | } |
| 36 | |
| 37 | public boolean hasNext() { |
| 38 | return false; |
| 39 | } |
| 40 | |
| 41 | public E next() { |
| 42 | throw new NoSuchElementException("Iterator contains no elements"); |
| 43 | } |
| 44 | |
| 45 | public boolean hasPrevious() { |
| 46 | return false; |
| 47 | } |
| 48 | |
| 49 | public E previous() { |
| 50 | throw new NoSuchElementException("Iterator contains no elements"); |
| 51 | } |
| 52 | |
| 53 | public int nextIndex() { |
| 54 | return 0; |
| 55 | } |
| 56 | |
| 57 | public int previousIndex() { |
| 58 | return -1; |
| 59 | } |
| 60 | |
| 61 | public void add(E obj) { |
| 62 | throw new UnsupportedOperationException("add() not supported for empty Iterator"); |
| 63 | } |
| 64 | |
| 65 | public void set(E obj) { |
| 66 | throw new IllegalStateException("Iterator contains no elements"); |
| 67 | } |
| 68 | |
| 69 | public void remove() { |
| 70 | throw new IllegalStateException("Iterator contains no elements"); |
| 71 | } |
| 72 | |
| 73 | public E getKey() { |
| 74 | throw new IllegalStateException("Iterator contains no elements"); |
| 75 | } |
| 76 | |
| 77 | public E getValue() { |
| 78 | throw new IllegalStateException("Iterator contains no elements"); |
| 79 | } |
| 80 | |
| 81 | public E setValue(E value) { |
| 82 | throw new IllegalStateException("Iterator contains no elements"); |
| 83 | } |
| 84 | |
| 85 | public void reset() { |
| 86 | // do nothing |
| 87 | } |
| 88 | |
| 89 | } |