1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 | /* * Converts an array to an iterator. * Copyright (C) 2004-2010 Stephen Ostermiller * http://ostermiller.org/contact.pl?regarding=Java+Utilities * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * See LICENSE.txt for details. */ package com.Ostermiller.util; import java.util.*; /** * Converts an array to an iterator. * <p> * More information about this class is available from <a target="_top" href= * "http://ostermiller.org/utils/Iterator_Enumeration.html">ostermiller.org</a>. * * @author Stephen Ostermiller http://ostermiller.org/contact.pl?regarding=Java+Utilities * @param <ElementType> Type of array over which to iterate * @since ostermillerutils 1.03.00 */ public class ArrayIterator<ElementType> implements Iterator<ElementType> { /** * Array being converted to iterator. */ private ElementType[] array; /** * Current index into the array. */ private int index = 0 ; /** * Whether the last element has been removed. */ private boolean lastRemoved = false ; /** * Create an Iterator from an Array. * * @param array of objects on which to enumerate. * * @since ostermillerutils 1.03.00 */ public ArrayIterator(ElementType[] array){ this .array = array; } /** * Tests if this Iterator contains more elements. * * @return true if and only if this Iterator object contains at least * one more element to provide; false otherwise. * * @since ostermillerutils 1.03.00 */ public boolean hasNext(){ return (index < array.length); } /** * Returns the next element of this Iterator if this Iterator * object has at least one more element to provide. * * @return the next element of this Iterator. * @throws NoSuchElementException if no more elements exist. * * @since ostermillerutils 1.03.00 */ public ElementType next() throws NoSuchElementException { if (index >= array.length) throw new NoSuchElementException( "Array index: " + index); ElementType object = array[index]; index++; lastRemoved = false ; return object; } /** * Removes the last object from the array by setting the slot in * the array to null. * This method can be called only once per call to next. * * @throws IllegalStateException if the next method has not yet been called, or the remove method has already been called after the last call to the next method. * * @since ostermillerutils 1.03.00 */ public void remove(){ if (index == 0 ) throw new IllegalStateException(); if (lastRemoved) throw new IllegalStateException(); array[index- 1 ] = null ; lastRemoved = true ; } } |