1 /* 2 * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/util/LinkedIterator.java,v 1.4 2003/06/29 18:01:34 ssanders Exp $ 3 * $Revision: 1.4 $ 4 * $Date: 2003/06/29 18:01:34 $ 5 * 6 * ==================================================================== 7 * 8 * Copyright (C) 2000-2002 bob mcwhirter & James Strachan. 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions, and the following disclaimer. 17 * 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions, and the disclaimer that follows 20 * these conditions in the documentation and/or other materials 21 * provided with the distribution. 22 * 23 * 3. The name "Jaxen" must not be used to endorse or promote products 24 * derived from this software without prior written permission. For 25 * written permission, please contact license@jaxen.org. 26 * 27 * 4. Products derived from this software may not be called "Jaxen", nor 28 * may "Jaxen" appear in their name, without prior written permission 29 * from the Jaxen Project Management (pm@jaxen.org). 30 * 31 * In addition, we request (but do not require) that you include in the 32 * end-user documentation provided with the redistribution and/or in the 33 * software itself an acknowledgement equivalent to the following: 34 * "This product includes software developed by the 35 * Jaxen Project (http://www.jaxen.org/)." 36 * Alternatively, the acknowledgment may be graphical using the logos 37 * available at http://www.jaxen.org/ 38 * 39 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 40 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 41 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 42 * DISCLAIMED. IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT 43 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 45 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 46 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 47 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 48 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 49 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 50 * SUCH DAMAGE. 51 * 52 * ==================================================================== 53 * This software consists of voluntary contributions made by many 54 * individuals on behalf of the Jaxen Project and was originally 55 * created by bob mcwhirter <bob@werken.com> and 56 * James Strachan <jstrachan@apache.org>. For more information on the 57 * Jaxen Project, please see <http://www.jaxen.org/>. 58 * 59 * $Id: LinkedIterator.java,v 1.4 2003/06/29 18:01:34 ssanders Exp $ 60 */ 61 62 63 package org.jaxen.util; 64 65 import java.util.ArrayList; 66 import java.util.Iterator; 67 import java.util.List; 68 import java.util.NoSuchElementException; 69 70 public class LinkedIterator implements Iterator 71 { 72 private List iterators; 73 private int cur; 74 75 public LinkedIterator() 76 { 77 this.iterators = new ArrayList(); 78 this.cur = 0; 79 } 80 81 public void addIterator(Iterator i) 82 { 83 this.iterators.add( i ); 84 } 85 86 public boolean hasNext() 87 { 88 boolean has = false; 89 90 if ( this.cur < this.iterators.size() ) 91 { 92 has = ((Iterator)this.iterators.get( this.cur )).hasNext(); 93 94 if ( ! has 95 && 96 this.cur < this.iterators.size() ) 97 { 98 ++this.cur; 99 has = hasNext(); 100 } 101 } 102 else 103 { 104 has = false; 105 } 106 107 return has; 108 } 109 110 public Object next() 111 { 112 if ( ! hasNext() ) 113 { 114 throw new NoSuchElementException(); 115 } 116 117 return ((Iterator)this.iterators.get( this.cur )).next(); 118 } 119 120 public void remove() 121 { 122 throw new UnsupportedOperationException(); 123 } 124 }