- /*
- * 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.lang.reflect.Array;
- import java.util.NoSuchElementException;
-
- import org.apache.commons.collections.ResettableIterator;
-
- /**
- * Implements an {@link java.util.Iterator Iterator} over any array.
- * <p>
- * The array can be either an array of object or of primitives. If you know
- * that you have an object array, the
- * {@link org.apache.commons.collections.iterators.ObjectArrayIterator ObjectArrayIterator}
- * class is a better choice, as it will perform better.
- * <p>
- * The iterator implements a {@link #reset} method, allowing the reset of
- * the iterator back to the start if required.
- *
- * @since Commons Collections 1.0
- * @version $Revision: 1.11 $ $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
- */
- public class ArrayIterator implements ResettableIterator {
-
- /** The array to iterate over */
- protected Object array;
- /** 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;
-
- // Constructors
- // ----------------------------------------------------------------------
- /**
- * Constructor for use with <code>setArray</code>.
- * <p>
- * Using this constructor, the iterator is equivalent to an empty iterator
- * until {@link #setArray(Object)} is called to establish the array to iterate over.
- */
- public ArrayIterator() {
- super();
- }
-
- /**
- * Constructs an ArrayIterator that will iterate over the values in the
- * specified array.
- *
- * @param array the array to iterate over.
- * @throws IllegalArgumentException if <code>array</code> is not an array.
- * @throws NullPointerException if <code>array</code> is <code>null</code>
- */
- public ArrayIterator(final Object array) {
- super();
- setArray(array);
- }
-
- /**
- * Constructs an ArrayIterator that will iterate over the values in the
- * specified array from a specific start index.
- *
- * @param array the array to iterate over.
- * @param startIndex the index to start iterating at.
- * @throws IllegalArgumentException if <code>array</code> is not an array.
- * @throws NullPointerException if <code>array</code> is <code>null</code>
- * @throws IndexOutOfBoundsException if the index is invalid
- */
- public ArrayIterator(final Object array, final int startIndex) {
- super();
- setArray(array);
- checkBound(startIndex, "start");
- this.startIndex = startIndex;
- this.index = startIndex;
- }
-
- /**
- * Construct an ArrayIterator that will iterate over a range of values
- * in the specified array.
- *
- * @param array the array to iterate over.
- * @param startIndex the index to start iterating at.
- * @param endIndex the index to finish iterating at.
- * @throws IllegalArgumentException if <code>array</code> is not an array.
- * @throws NullPointerException if <code>array</code> is <code>null</code>
- * @throws IndexOutOfBoundsException if either index is invalid
- */
- public ArrayIterator(final Object array, final int startIndex, final int endIndex) {
- super();
- setArray(array);
- checkBound(startIndex, "start");
- checkBound(endIndex, "end");
- if (endIndex < startIndex) {
- throw new IllegalArgumentException("End index must not be less than start index.");
- }
- this.startIndex = startIndex;
- this.endIndex = endIndex;
- this.index = startIndex;
- }
-
- /**
- * Checks whether the index is valid or not.
- *
- * @param bound the index to check
- * @param type the index type (for error messages)
- * @throws IndexOutOfBoundsException if the index is invalid
- */
- protected void checkBound(final int bound, final String type ) {
- if (bound > this.endIndex) {
- throw new ArrayIndexOutOfBoundsException(
- "Attempt to make an ArrayIterator that " + type +
- "s beyond the end of the array. "
- );
- }
- if (bound < 0) {
- throw new ArrayIndexOutOfBoundsException(
- "Attempt to make an ArrayIterator that " + type +
- "s before the start of the array. "
- );
- }
- }
-
- // 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 (index < 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 Array.get(array, index++);
- }
-
- /**
- * Throws {@link UnsupportedOperationException}.
- *
- * @throws UnsupportedOperationException always
- */
- public void remove() {
- throw new UnsupportedOperationException("remove() method is not supported");
- }
-
- // 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(Object)} has never
- * been called with a valid array.
- */
- public Object getArray() {
- return array;
- }
-
- /**
- * Sets the array that the ArrayIterator should iterate over.
- * <p>
- * If an array has previously been set (using the single-arg constructor
- * or this method) then that array is discarded in favour of this one.
- * Iteration is restarted at the start of the new array.
- * Although this can be used to reset iteration, the {@link #reset()} method
- * is a more effective choice.
- *
- * @param array the array that the iterator should iterate over.
- * @throws IllegalArgumentException if <code>array</code> is not an array.
- * @throws NullPointerException if <code>array</code> is <code>null</code>
- */
- public void setArray(final Object array) {
- // Array.getLength throws IllegalArgumentException if the object is not
- // an array or NullPointerException if the object is null. This call
- // is made before saving the array and resetting the index so that the
- // array iterator remains in a consistent state if the argument is not
- // an array or is null.
- this.endIndex = Array.getLength(array);
- this.startIndex = 0;
- this.array = array;
- this.index = 0;
- }
-
- /**
- * Resets the iterator back to the start index.
- */
- public void reset() {
- this.index = this.startIndex;
- }
-
- }