Adding SetList decorator from bug #22826

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/collections/trunk@131220 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Matthew Hawthorne 2003-10-02 22:34:44 +00:00
parent a3155911c2
commit 54f2a8e85b
3 changed files with 414 additions and 2 deletions

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/*
* $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//collections/src/java/org/apache/commons/collections/decorators/Attic/SetList.java,v 1.1 2003/10/02 22:34:44 matth Exp $
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 2001-2003 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 acknowledgement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgement may appear in the software itself,
* if and wherever such third-party acknowledgements 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 Software Foundation.
*
* 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
* <http://www.apache.org/>.
*
*/
package org.apache.commons.collections.decorators;
import java.util.AbstractList;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
/**
* SetList combines the <code>List</code> and <code>Set</code> interfaces
* in one implementation.
* <p>
* The <code>List</code> interface makes certain assumptions/requirements.
* This implementation breaks these in certain ways, but this is merely the
* result of rejecting duplicates.
* Each violation is explained in the method, but it should not affect you.
* <p>
* The {@link org.apache.commons.collections.decorators.OrderedSet OrderedSet}
* class provides an alternative approach, by wrapping an existing Set and
* retaining insertion order in the iterator. This class offers the <code>List</code>
* interface implementation as well.
* <p>
* If the <code>Set</code> aspects are important to you (fast add/contains/remove)
* then <code>OrderedSet</code> is a better choice.
* This implementation is based solely on <code>ArrayList</code>, and so has
* slow add/contains/remove operations for all except small lists.
*
* @since Commons Collections 3.0
* @version $Revision: 1.1 $ $Date: 2003/10/02 22:34:44 $
*
* @author Matthew Hawthorne
* @author Stephen Colebourne
*/
public class SetList extends AbstractList {
/**
* Delegate list.
*/
private final List delegate = new ArrayList();
/**
* Helps to maintain uniqueness.
*/
private final Set set = new HashSet();
/**
* Factory method to create a SetList.
* @param list the list to decorate
*/
public static SetList decorate(List list) {
return new SetList(list);
}
/**
* Contructs an new list copying the specified elements.
* @param coll a collection to copy
*/
protected SetList(List list) {
addAll(list);
}
//-----------------------------------------------------------------------
/**
* Adds an element to the list if it is not already present.
* <p>
* <i>(Violation)</i>
* The <code>List</code> interface requires that this method returns
* <code>true</code> always. However this class may return <code>false</code>
* because of the <code>Set</code> behaviour.
*
* @param object the object to add
* @return true if object was added
*/
public boolean add(Object object) {
// gets initial size
final int sizeBefore = size();
// adds element if unique
add(size(), object);
// compares sizes to detect if collection changed
return (sizeBefore != size());
}
/**
* Adds an element to a specific index in the list if it is not already present.
* <p>
* <i>(Violation)</i>
* The <code>List</code> interface makes the assumption that the element is
* always inserted. This may not happen with this implementation.
*
* @param index the index to insert at
* @param object the object to add
*/
public void add(int index, Object object) {
// Adds element if it is not contained already
if (!set.contains(object)) {
delegate.add(index, object);
set.add(object);
}
}
//-----------------------------------------------------------------------
/**
* Adds a collection of objects to the end of the list avoiding duplicates.
* <p>
* Only elements that are not already in this list will be added, and
* duplicates from the specified collection will be ignored.
* <p>
* <i>(Violation)</i>
* The <code>List</code> interface makes the assumption that the elements
* are always inserted. This may not happen with this implementation.
*
* @param index the index to insert at
* @param coll the collection to add in iterator order
* @return true if this collection changed
*/
public boolean addAll(int index, Collection coll) {
// gets initial size
final int sizeBefore = size();
// adds all elements
for (final Iterator it = coll.iterator(); it.hasNext();) {
add(it.next());
}
// compares sizes to detect if collection changed
return sizeBefore != size();
}
//-----------------------------------------------------------------------
/**
* Sets the value at the specified index avoiding duplicates.
* <p>
* The object is set into the specified index.
* Afterwards, any previous duplicate is removed
* If the object is not already in the list then a normal set occurs.
* If it is present, then the old version is removed and re-added at this index
*
* @param index the index to insert at
* @param object the object to set
* @return the previous object
*/
public Object set(int index, Object object) {
int pos = indexOf(object);
Object result = delegate.set(index, object);
if (pos == -1 || pos == index) {
return result;
}
return remove(pos);
}
public Object get(int index) {
return delegate.get(index);
}
public int size() {
return delegate.size();
}
public Object remove(int index) {
return delegate.remove(index);
}
public void clear() {
delegate.clear();
set.clear();
}
}

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/*
* $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//collections/src/test/org/apache/commons/collections/decorators/Attic/TestAll.java,v 1.15 2003/09/20 16:57:20 scolebourne Exp $
* $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//collections/src/test/org/apache/commons/collections/decorators/Attic/TestAll.java,v 1.16 2003/10/02 22:34:44 matth Exp $
* ====================================================================
*
* The Apache Software License, Version 1.1
@ -65,7 +65,7 @@ import junit.framework.TestSuite;
* Entry point for all collections decorators tests.
*
* @since Commons Collections 3.0
* @version $Revision: 1.15 $ $Date: 2003/09/20 16:57:20 $
* @version $Revision: 1.16 $ $Date: 2003/10/02 22:34:44 $
*
* @author Stephen Colebourne
*/
@ -93,6 +93,7 @@ public class TestAll extends TestCase {
suite.addTest(TestLazySortedMap.suite());
suite.addTest(TestOrderedSet.suite());
suite.addTest(TestSetList.suite());
suite.addTest(TestTransformedBag.suite());
suite.addTest(TestTransformedBuffer.suite());

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/*
* $Header: /home/jerenkrantz/tmp/commons/commons-convert/cvs/home/cvs/jakarta-commons//collections/src/test/org/apache/commons/collections/decorators/Attic/TestSetList.java,v 1.1 2003/10/02 22:34:44 matth Exp $
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 2001-2003 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 acknowledgement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgement may appear in the software itself,
* if and wherever such third-party acknowledgements 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 Software Foundation.
*
* 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
* <http://www.apache.org/>.
*
*/
package org.apache.commons.collections.decorators;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.ListIterator;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import junit.textui.TestRunner;
/**
* JUnit tests.
*
* @since Commons Collections 3.0
* @version $Revision: 1.1 $ $Date: 2003/10/02 22:34:44 $
*
* @author Matthew Hawthorne
*/
public class TestSetList extends TestCase {
public static void main(String[] args) {
TestRunner.run(suite());
}
public static Test suite() {
return new TestSuite(TestSetList.class);
}
public TestSetList(String testName) {
super(testName);
}
//-----------------------------------------------------------------------
public void testConstructor() {
final SetList lset =
new SetList(
Arrays.asList(new Integer[] { new Integer(1), new Integer(1)}));
assertEquals("Duplicate element was added.", 1, lset.size());
}
public void testAdd() {
final SetList lset = new SetList(new ArrayList());
// Duplicate element
final Object obj = new Integer(1);
lset.add(obj);
lset.add(obj);
assertEquals("Duplicate element was added.", 1, lset.size());
// Unique element
lset.add(new Integer(2));
assertEquals("Unique element was not added.", 2, lset.size());
}
public void testAddAll() {
final SetList lset = new SetList(new ArrayList());
lset.addAll(
Arrays.asList(new Integer[] { new Integer(1), new Integer(1)}));
assertEquals("Duplicate element was added.", 1, lset.size());
}
public void testSet() {
final SetList lset = new SetList(new ArrayList());
// Duplicate element
final Object obj1 = new Integer(1);
final Object obj2 = new Integer(2);
final Object obj3 = new Integer(3);
lset.add(obj1);
lset.add(obj2);
lset.set(0, obj1);
assertEquals(2, lset.size());
assertSame(obj1, lset.get(0));
assertSame(obj2, lset.get(1));
lset.clear();
lset.add(obj1);
lset.add(obj2);
lset.set(0, obj2);
assertEquals(1, lset.size());
assertSame(obj2, lset.get(0));
lset.clear();
lset.add(obj1);
lset.add(obj2);
lset.set(0, obj3);
assertEquals(2, lset.size());
assertSame(obj3, lset.get(0));
assertSame(obj2, lset.get(1));
lset.clear();
lset.add(obj1);
lset.add(obj2);
lset.set(1, obj1);
assertEquals(1, lset.size());
assertSame(obj1, lset.get(0));
}
public void testListIterator() {
final SetList lset = new SetList(new ArrayList());
final Object obj1 = new Integer(1);
final Object obj2 = new Integer(2);
lset.add(obj1);
lset.add(obj2);
// Attempts to add a duplicate object
for (final ListIterator it = lset.listIterator(); it.hasNext();) {
it.next();
if (!it.hasNext()) {
it.add(obj1);
break;
}
}
assertEquals("Duplicate element was added", 2, lset.size());
}
}