From 6c21eb2aa179bddd80030066cc43c4a68af3d741 Mon Sep 17 00:00:00 2001 From: Morgan James Delagrange Date: Tue, 9 Apr 2002 16:40:58 +0000 Subject: [PATCH] ListIteratorWrapper allows Iterators to simulate ListIterator behaviour git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/collections/trunk@130689 13f79535-47bb-0310-9956-ffa450edef68 --- .../collections/ListIteratorWrapper.java | 163 ++++++++++++++++ .../collections/TestListIteratorWrapper.java | 179 ++++++++++++++++++ 2 files changed, 342 insertions(+) create mode 100644 src/java/org/apache/commons/collections/ListIteratorWrapper.java create mode 100644 src/test/org/apache/commons/collections/TestListIteratorWrapper.java diff --git a/src/java/org/apache/commons/collections/ListIteratorWrapper.java b/src/java/org/apache/commons/collections/ListIteratorWrapper.java new file mode 100644 index 000000000..bf4fa5c51 --- /dev/null +++ b/src/java/org/apache/commons/collections/ListIteratorWrapper.java @@ -0,0 +1,163 @@ +/* + * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//collections/src/java/org/apache/commons/collections/Attic/ListIteratorWrapper.java,v 1.1 2002/04/09 16:40:43 morgand Exp $ + * $Revision: 1.1 $ + * $Date: 2002/04/09 16:40:43 $ + * + * ==================================================================== + * + * The Apache Software License, Version 1.1 + * + * Copyright (c) 1999-2002 The Apache Software Foundation. All rights + * reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * 3. The end-user documentation included with the redistribution, if + * any, must include the following acknowlegement: + * "This product includes software developed by the + * Apache Software Foundation (http://www.apache.org/)." + * Alternately, this acknowlegement may appear in the software itself, + * if and wherever such third-party acknowlegements normally appear. + * + * 4. The names "The Jakarta Project", "Commons", and "Apache Software + * Foundation" must not be used to endorse or promote products derived + * from this software without prior written permission. For written + * permission, please contact apache@apache.org. + * + * 5. Products derived from this software may not be called "Apache" + * nor may "Apache" appear in their names without prior written + * permission of the Apache Group. + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR + * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * ==================================================================== + * + * This software consists of voluntary contributions made by many + * individuals on behalf of the Apache Software Foundation. For more + * information on the Apache Software Foundation, please see + * . + * + */ +package org.apache.commons.collections; + +import java.util.Iterator; +import java.util.LinkedList; +import java.util.ListIterator; +import java.util.NoSuchElementException; + +/** + * As the wrapped Iterator is traversed, ListIteratorWrapper + * builds a LinkedList of its values, permitting all required + * operations of ListIterator. + * + * @author Morgan Delagrange + * @version $Revision: 1.1 $ $Date: 2002/04/09 16:40:43 $ + */ +public class ListIteratorWrapper implements ListIterator { + + // Constructor + //------------------------------------------------------------------------- + + public ListIteratorWrapper(Iterator iterator) { + this.iterator = iterator; + } + + // ListIterator interface + //------------------------------------------------------------------------- + + public void add(Object o) throws UnsupportedOperationException { + throw new UnsupportedOperationException(UNSUPPORTED_OPERATION_MESSAGE); + } + + public boolean hasNext() { + if (currentIndex == wrappedIteratorIndex) { + return iterator.hasNext(); + } + + return true; + } + + public boolean hasPrevious() { + if (currentIndex == 0) { + return false; + } + + return true; + } + + public Object next() throws NoSuchElementException { + if (currentIndex < wrappedIteratorIndex) { + ++currentIndex; + return list.get(currentIndex - 1); + } + + Object retval = iterator.next(); + list.add(retval); + ++currentIndex; + ++wrappedIteratorIndex; + return retval; + } + + public int nextIndex() { + return currentIndex; + } + + public Object previous() throws NoSuchElementException { + if (currentIndex == 0) { + throw new NoSuchElementException(); + } + + --currentIndex; + return list.get(currentIndex); + } + + public int previousIndex() { + return currentIndex - 1; + } + + public void remove() throws UnsupportedOperationException { + throw new UnsupportedOperationException(UNSUPPORTED_OPERATION_MESSAGE); + } + + public void set(Object o) throws UnsupportedOperationException { + throw new UnsupportedOperationException(UNSUPPORTED_OPERATION_MESSAGE); + } + + // Attributes + //------------------------------------------------------------------------- + + /** Holds value of property "iterator". */ + private Iterator iterator = null; + private LinkedList list = new LinkedList(); + + // position of this iterator + private int currentIndex = 0; + // position of the wrapped iterator + // this Iterator should only be used to populate the list + private int wrappedIteratorIndex = 0; + + private static final String UNSUPPORTED_OPERATION_MESSAGE = + "ListIteratorWrapper does not support optional operations of ListIterator."; + +} + diff --git a/src/test/org/apache/commons/collections/TestListIteratorWrapper.java b/src/test/org/apache/commons/collections/TestListIteratorWrapper.java new file mode 100644 index 000000000..06ccef431 --- /dev/null +++ b/src/test/org/apache/commons/collections/TestListIteratorWrapper.java @@ -0,0 +1,179 @@ +/* + * $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//collections/src/test/org/apache/commons/collections/Attic/TestListIteratorWrapper.java,v 1.1 2002/04/09 16:40:58 morgand Exp $ + * $Revision: 1.1 $ + * $Date: 2002/04/09 16:40:58 $ + * + * ==================================================================== + * + * The Apache Software License, Version 1.1 + * + * Copyright (c) 1999-2001 The Apache Software Foundation. All rights + * reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * 3. The end-user documentation included with the redistribution, if + * any, must include the following acknowlegement: + * "This product includes software developed by the + * Apache Software Foundation (http://www.apache.org/)." + * Alternately, this acknowlegement may appear in the software itself, + * if and wherever such third-party acknowlegements normally appear. + * + * 4. The names "The Jakarta Project", "Commons", and "Apache Software + * Foundation" must not be used to endorse or promote products derived + * from this software without prior written permission. For written + * permission, please contact apache@apache.org. + * + * 5. Products derived from this software may not be called "Apache" + * nor may "Apache" appear in their names without prior written + * permission of the Apache Group. + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR + * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * ==================================================================== + * + * This software consists of voluntary contributions made by many + * individuals on behalf of the Apache Software Foundation. For more + * information on the Apache Software Foundation, please see + * . + * + */ + +package org.apache.commons.collections; + +import junit.framework.*; +import java.io.Serializable; +import java.util.ArrayList; +import java.util.Iterator; +import java.util.List; +import java.util.ListIterator; +import java.util.NoSuchElementException; + +/** + * Tests the ListIteratorWrapper to insure that it simulates + * a ListIterator correctly. + * + * @author Morgan Delagrange + * @version $Id: TestListIteratorWrapper.java,v 1.1 2002/04/09 16:40:58 morgand Exp $ + */ +public class TestListIteratorWrapper extends TestIterator { + + protected String[] testArray = { + "One", "Two", "Three", "Four", "Five", "Six" + }; + + protected List list1 = null; + + public static Test suite() { + return new TestSuite(TestListIteratorWrapper.class); + } + + public TestListIteratorWrapper(String testName) { + super(testName); + } + + public void setUp() { + list1 = new ArrayList(); + list1.add("One"); + list1.add("Two"); + list1.add("Three"); + list1.add("Four"); + list1.add("Five"); + list1.add("Six"); + } + + public Iterator makeEmptyIterator() { + ArrayList list = new ArrayList(); + return new ListIteratorWrapper(list.iterator()); + } + + public Iterator makeFullIterator() { + Iterator i = list1.iterator(); + + return new ListIteratorWrapper(i); + } + + /** + * Return a new, empty {@link Object} to used for testing. + */ + public Object makeObject() { + return makeFullIterator(); + } + + public void testIterator() { + ListIterator iter = (ListIterator) makeFullIterator(); + for ( int i = 0; i < testArray.length; i++ ) { + Object testValue = testArray[i]; + Object iterValue = iter.next(); + + assertEquals( "Iteration value is correct", testValue, iterValue ); + } + + assertTrue("Iterator should now be empty", ! iter.hasNext() ); + + try { + Object testValue = iter.next(); + } catch (Exception e) { + assertTrue("NoSuchElementException must be thrown", + e.getClass().equals((new NoSuchElementException()).getClass())); + } + + // now, read it backwards + for (int i = testArray.length - 1; i > -1; --i) { + Object testValue = testArray[i]; + Object iterValue = iter.previous(); + + assertEquals( "Iteration value is correct", testValue, iterValue ); + } + + try { + Object testValue = iter.previous(); + } catch (Exception e) { + assertTrue("NoSuchElementException must be thrown", + e.getClass().equals((new NoSuchElementException()).getClass())); + } + + // now, read it forwards again + for ( int i = 0; i < testArray.length; i++ ) { + Object testValue = testArray[i]; + Object iterValue = iter.next(); + + assertEquals( "Iteration value is correct", testValue, iterValue ); + } + + } + + public void testRemove() { + Iterator iter = (Iterator) makeFullIterator(); + + try { + iter.remove(); + fail("FilterIterator does not support the remove() method"); + } catch (UnsupportedOperationException e) { + + } + + } + +} +