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	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You 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.NoSuchElementException;

	import org.apache.commons.collections4.ResettableIterator;

	/**
	* An {@link java.util.Iterator Iterator} over an array of objects.
	* <p>
	* This iterator does not support {@link #remove}, as the object array cannot be
	* structurally modified.
	* <p>
	* The iterator implements a {@link #reset} method, allowing the reset of the iterator
	* back to the start if required.
	*
	* @param <E> the type of elements returned by this iterator
	* @since 3.0
	*/
	public class ObjectArrayIterator<E> implements ResettableIterator<E> {

	/** The array */
	final E[] array;
	/** The start index to loop from */
	final int startIndex;
	/** The end index to loop to */
	final int endIndex;
	/** The current iterator index */
	int index = 0;

	//-------------------------------------------------------------------------
	/**
	* Constructs an ObjectArrayIterator that will iterate over the values in the
	* specified array.
	*
	* @param array the array to iterate over
	* @throws NullPointerException if <code>array</code> is <code>null</code>
	*/
	public ObjectArrayIterator(final E... array) {
	this(array, 0, array.length);
	}

	/**
	* Constructs an ObjectArrayIterator that will iterate over the values in the
	* specified array from a specific start index.
	*
	* @param array the array to iterate over
	* @param start the index to start iterating at
	* @throws NullPointerException if <code>array</code> is <code>null</code>
	* @throws IndexOutOfBoundsException if the start index is out of bounds
	*/
	public ObjectArrayIterator(final E array[], final int start) {
	this(array, start, array.length);
	}

	/**
	* Construct an ObjectArrayIterator that will iterate over a range of values
	* in the specified array.
	*
	* @param array the array to iterate over
	* @param start the index to start iterating at
	* @param end the index (exclusive) to finish iterating at
	* @throws IndexOutOfBoundsException if the start or end index is out of bounds
	* @throws IllegalArgumentException if end index is before the start
	* @throws NullPointerException if <code>array</code> is <code>null</code>
	*/
	public ObjectArrayIterator(final E array[], final int start, final int end) {
	super();
	if (start < 0) {
	throw new ArrayIndexOutOfBoundsException("Start index must not be less than zero");
	}
	if (end > array.length) {
	throw new ArrayIndexOutOfBoundsException("End index must not be greater than the array length");
	}
	if (start > array.length) {
	throw new ArrayIndexOutOfBoundsException("Start index must not be greater than the array length");
	}
	if (end < start) {
	throw new IllegalArgumentException("End index must not be less than start index");
	}
	this.array = array;
	this.startIndex = start;
	this.endIndex = end;
	this.index = start;
	}

	// Iterator interface
	//-------------------------------------------------------------------------

	/**
	* Returns true if there are more elements to return from the array.
	*
	* @return true if there is a next element to return
	*/
	@Override
	public boolean hasNext() {
	return this.index < this.endIndex;
	}

	/**
	* Returns the next element in the array.
	*
	* @return the next element in the array
	* @throws NoSuchElementException if all the elements in the array
	* have already been returned
	*/
	@Override
	public E next() {
	if (hasNext() == false) {
	throw new NoSuchElementException();
	}
	return this.array[this.index++];
	}

	/**
	* Throws {@link UnsupportedOperationException}.
	*
	* @throws UnsupportedOperationException always
	*/
	@Override
	public void remove() {
	throw new UnsupportedOperationException("remove() method is not supported for an ObjectArrayIterator");
	}

	// Properties
	//-------------------------------------------------------------------------

	/**
	* Gets the array that this iterator is iterating over.
	*
	* @return the array this iterator iterates over
	*/
	public E[] getArray() {
	return this.array;
	}

	/**
	* Gets the start index to loop from.
	*
	* @return the start index
	*/
	public int getStartIndex() {
	return this.startIndex;
	}

	/**
	* Gets the end index to loop to.
	*
	* @return the end index
	*/
	public int getEndIndex() {
	return this.endIndex;
	}

	/**
	* Resets the iterator back to the start index.
	*/
	@Override
	public void reset() {
	this.index = this.startIndex;
	}

	}

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