001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.collections4.iterators; 018 019import java.util.Iterator; 020import java.util.NoSuchElementException; 021import java.util.Objects; 022 023import org.w3c.dom.Node; 024import org.w3c.dom.NodeList; 025 026/** 027 * An {@link Iterator} over a {@link NodeList}. 028 * <p> 029 * This iterator does not support {@link #remove()} as a {@link NodeList} does not support 030 * removal of items. 031 * 032 * @since 4.0 033 * @see NodeList 034 */ 035public class NodeListIterator implements Iterator<Node> { 036 037 /** The original NodeList instance */ 038 private final NodeList nodeList; 039 /** The current iterator index */ 040 private int index; 041 042 /** 043 * Convenience constructor, which creates a new NodeListIterator from 044 * the specified node's childNodes. 045 * 046 * @param node Node, whose child nodes are wrapped by this class. Must not be null 047 * @throws NullPointerException if node is null 048 */ 049 public NodeListIterator(final Node node) { 050 Objects.requireNonNull(node, "node"); 051 this.nodeList = node.getChildNodes(); 052 } 053 054 /** 055 * Constructor, that creates a new NodeListIterator from the specified 056 * {@code org.w3c.NodeList} 057 * 058 * @param nodeList node list, which is wrapped by this class. Must not be null 059 * @throws NullPointerException if nodeList is null 060 */ 061 public NodeListIterator(final NodeList nodeList) { 062 this.nodeList = Objects.requireNonNull(nodeList, "nodeList"); 063 } 064 065 @Override 066 public boolean hasNext() { 067 return nodeList != null && index < nodeList.getLength(); 068 } 069 070 @Override 071 public Node next() { 072 if (nodeList != null && index < nodeList.getLength()) { 073 return nodeList.item(index++); 074 } 075 throw new NoSuchElementException("underlying nodeList has no more elements"); 076 } 077 078 /** 079 * Throws {@link UnsupportedOperationException}. 080 * 081 * @throws UnsupportedOperationException always 082 */ 083 @Override 084 public void remove() { 085 throw new UnsupportedOperationException("remove() method not supported for a NodeListIterator."); 086 } 087}