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/*
* Copyright 2013 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.collections4.iterators;
import java.util.Iterator;
import java.util.NoSuchElementException;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
/**
* An {@link Iterator} over a {@link NodeList}.
*
* This iterator does not support {@link #remove()} as a {@link NodeList} does not support
* removal of items.
*
* @since 4.0
* @see NodeList
*/
public class NodeListIterator implements Iterator {
/** the original NodeList instance */
private final NodeList nodeList;
/** The current iterator index */
private int index = 0;
/**
* Convenience constructor, which creates a new NodeListIterator from
* the specified node's childNodes.
*
* @param node Node, who's child nodes are wrapped by this class. Must not be null
* @throws NullPointerException if node is null
*/
public NodeListIterator(final Node node) {
if (node == null) {
throw new NullPointerException("Node must not be null.");
}
this.nodeList = node.getChildNodes();
}
/**
* Constructor, that creates a new NodeListIterator from the specified
* org.w3c.NodeList
*
* @param nodeList node list, which is wrapped by this class. Must not be null
* @throws NullPointerException if nodeList is null
*/
public NodeListIterator(final NodeList nodeList) {
if (nodeList == null) {
throw new NullPointerException("NodeList must not be null.");
}
this.nodeList = nodeList;
}
@Override
public boolean hasNext() {
return nodeList != null && index < nodeList.getLength();
}
@Override
public Node next() {
if (nodeList != null && index < nodeList.getLength()) {
return nodeList.item(index++);
}
throw new NoSuchElementException("underlying nodeList has no more elements");
}
/**
* Throws {@link UnsupportedOperationException}.
*
* @throws UnsupportedOperationException always
*/
@Override
public void remove() {
throw new UnsupportedOperationException("remove() method not supported for a NodeListIterator.");
}
}