xdocs/history.xml - commons-collections - Git at Google

 <?xml version="1.0" encoding="ISO-8859-1"?>
  <!--
    Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You 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.
   -->

 <document>

  <properties>
   <title>History</title>
   <author email="dev@commons.apache.org">Commons Documentation Team</author>
  </properties>

  <body>

 <section name="History of Commons Collections">

 <p>
 Commons-Collections is a classic example of an open-source project evolving over time.
 This page documents some of the key stages.
 </p>

 <p>
 <b>Collections 1.0</b> was a gathering of different Collection, Comparator, Iterator and
 Utility classes written elsewhere in Jakarta.
 At this stage, the component focussed mainly on getting re-use of code by making
 everything available together.
 </p>
 <p>
 All classes were placed in one package except the comparators, which had their own subpackage.
 </p>

 <p>
 <b>Collections 2.0</b> started the process of growth. The Bag interface was added with
 various implementations. Also added were additional collections implementations.
 </p>
 <p>
 All classes were placed in one package except the comparators, which had their own subpackage.
 </p>

 <p>
 <b>Collections 2.1</b> increased the growth again. The Buffer interface was added, unifying
 various previous implementations. Numerous decorators were added as inner classes that
 behave like the unmodifiable or synchronized JDK decorators.
 </p>
 <p>
 As the size of the component increased, the iterators were broken out into their own subpackage.
 Thus there were now three packages, main, comparator and iterator.
 </p>

 <p>
 <b>Collections 3.0</b> represented a re-birth of collections after an 18 month absence.
 Many, many classes were added to CVS but not released including primitive and
 event-generating classes. In order to control the size of the collections distribution,
 these became two new projects - primitives and events.
 </p>
 <p>
 New interfaces BidiMap, MapIterator, ResettableIterator and KeyValue were added.
 Also added were many new implementations of existing collections, especially Maps.
 </p>
 <p>
 As more decorators were added the decision was taken to create a new subpackage for
 the decorators (no more inner classes). However, it became clear that whether a class was
 a decorator or not was not the most important division in finding a collection.
 As a result of this, and the general ongoing growth in the component, a full subpackage
 layout was chosen - one subpackage for each principal collections interface.
 </p>
 <p>
 Essentially the 3.0 release represented the result of changing from a 'dumping ground'
 of re-used collections to a component <b>designed</b> for the purpose.
 Of course, backwards compatibility has been retained during all transitions using deprecation.
 </p>

 <p>
 <b>Collections 2.1.1</b> was a patch release to v2.1.
 Unfortunately, v3.0 created a <a href="compatibility.html">binary incompatibility</a> in the IteratorUtils class.
 This patch was created as a work around, enabling v2.1.1 to be compatible with v3.1.
 </p>

 <p>
 <b>Collections 3.1</b> fixed some bugs in v3.0 and adds a few new enhancements.
 The most notable change is a new list implementation, TreeList, that is well balanced for insertions and removals at any index.
 Other changes included more classes implementing Serializable and a ReferenceIdentityMap.
 </p>

 <p>
 <b>Collections 3.2</b> combined bug fixes and some new features.
 Notably MultiValueMap is a new more flexible implementation of MultiHashMap.
 </p>

 <p>
 <b>Collections 3.2.1</b> Re-packaged v3.2 release which is OSGi enabled.
 </p>

 </section>

 </body>
 </document>
	<?xml version="1.0" encoding="ISO-8859-1"?>
	<!--
	Licensed to the Apache Software Foundation (ASF) under one or more
	contributor license agreements. See the NOTICE file distributed with
	this work for additional information regarding copyright ownership.
	The ASF licenses this file to You 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.
	-->

	<document>

	<properties>
	<title>History</title>
	<author email="dev@commons.apache.org">Commons Documentation Team</author>
	</properties>

	<body>

	<section name="History of Commons Collections">

	<p>
	Commons-Collections is a classic example of an open-source project evolving over time.
	This page documents some of the key stages.
	</p>

	<p>
	<b>Collections 1.0</b> was a gathering of different Collection, Comparator, Iterator and
	Utility classes written elsewhere in Jakarta.
	At this stage, the component focussed mainly on getting re-use of code by making
	everything available together.
	</p>
	<p>
	All classes were placed in one package except the comparators, which had their own subpackage.
	</p>

	<p>
	<b>Collections 2.0</b> started the process of growth. The Bag interface was added with
	various implementations. Also added were additional collections implementations.
	</p>
	<p>
	All classes were placed in one package except the comparators, which had their own subpackage.
	</p>

	<p>
	<b>Collections 2.1</b> increased the growth again. The Buffer interface was added, unifying
	various previous implementations. Numerous decorators were added as inner classes that
	behave like the unmodifiable or synchronized JDK decorators.
	</p>
	<p>
	As the size of the component increased, the iterators were broken out into their own subpackage.
	Thus there were now three packages, main, comparator and iterator.
	</p>

	<p>
	<b>Collections 3.0</b> represented a re-birth of collections after an 18 month absence.
	Many, many classes were added to CVS but not released including primitive and
	event-generating classes. In order to control the size of the collections distribution,
	these became two new projects - primitives and events.
	</p>
	<p>
	New interfaces BidiMap, MapIterator, ResettableIterator and KeyValue were added.
	Also added were many new implementations of existing collections, especially Maps.
	</p>
	<p>
	As more decorators were added the decision was taken to create a new subpackage for
	the decorators (no more inner classes). However, it became clear that whether a class was
	a decorator or not was not the most important division in finding a collection.
	As a result of this, and the general ongoing growth in the component, a full subpackage
	layout was chosen - one subpackage for each principal collections interface.
	</p>
	<p>
	Essentially the 3.0 release represented the result of changing from a 'dumping ground'
	of re-used collections to a component <b>designed</b> for the purpose.
	Of course, backwards compatibility has been retained during all transitions using deprecation.
	</p>

	<p>
	<b>Collections 2.1.1</b> was a patch release to v2.1.
	Unfortunately, v3.0 created a <a href="compatibility.html">binary incompatibility</a> in the IteratorUtils class.
	This patch was created as a work around, enabling v2.1.1 to be compatible with v3.1.
	</p>

	<p>
	<b>Collections 3.1</b> fixed some bugs in v3.0 and adds a few new enhancements.
	The most notable change is a new list implementation, TreeList, that is well balanced for insertions and removals at any index.
	Other changes included more classes implementing Serializable and a ReferenceIdentityMap.
	</p>

	<p>
	<b>Collections 3.2</b> combined bug fixes and some new features.
	Notably MultiValueMap is a new more flexible implementation of MultiHashMap.
	</p>

	<p>
	<b>Collections 3.2.1</b> Re-packaged v3.2 release which is OSGi enabled.
	</p>

	</section>

	</body>
	</document>