- /*
- * Copyright 1999-2004 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.collections.iterators;
-
- import java.util.Iterator;
- import java.util.NoSuchElementException;
-
- import org.apache.commons.collections.ResettableIterator;
-
- /**
- * An {@link 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.
- *
- * @since Commons Collections 3.0
- * @version $Revision: 1.12 $ $Date: 2004/02/18 00:59:50 $
- *
- * @author James Strachan
- * @author Mauricio S. Moura
- * @author Michael A. Smith
- * @author Neil O'Toole
- * @author Stephen Colebourne
- * @author Phil Steitz
- */
- public class ObjectArrayIterator
- implements Iterator, ResettableIterator {
-
- /** The array */
- protected Object[] array = null;
- /** The start index to loop from */
- protected int startIndex = 0;
- /** The end index to loop to */
- protected int endIndex = 0;
- /** The current iterator index */
- protected int index = 0;
-
- /**
- * Constructor for use with <code>setArray</code>.
- * <p>
- * Using this constructor, the iterator is equivalent to an empty iterator
- * until {@link #setArray} is called to establish the array to iterate over.
- */
- public ObjectArrayIterator() {
- super();
- }
-
- /**
- * 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(Object[] 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(Object array[], 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(Object array[], int start, 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
- */
- 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
- */
- public Object next() {
- if (hasNext() == false) {
- throw new NoSuchElementException();
- }
- return this.array[this.index++];
- }
-
- /**
- * Throws {@link UnsupportedOperationException}.
- *
- * @throws UnsupportedOperationException always
- */
- 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, or <code>null</code> if
- * the no-arg constructor was used and {@link #setArray} has never
- * been called with a valid array.
- */
- public Object[] getArray() {
- return this.array;
- }
-
- /**
- * Sets the array that the ArrayIterator should iterate over.
- * <p>
- * This method may only be called once, otherwise an IllegalStateException
- * will occur.
- * <p>
- * The {@link #reset} method can be used to reset the iterator if required.
- *
- * @param array the array that the iterator should iterate over
- * @throws IllegalStateException if the <code>array</code> was set in the constructor
- * @throws NullPointerException if <code>array</code> is <code>null</code>
- */
- public void setArray(Object[] array) {
- if (this.array != null) {
- throw new IllegalStateException("The array to iterate over has already been set");
- }
- this.array = array;
- this.startIndex = 0;
- this.endIndex = array.length;
- this.index = 0;
- }
-
- /**
- * 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.
- */
- public void reset() {
- this.index = this.startIndex;
- }
-
- }