association.java

一个数据挖掘软件ALPHAMINERR的整个过程的JAVA版源代码

/*
 *    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.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/**
 * Title: XELOPES Data Mining Library
 * Description: The XELOPES library is an open platform-independent and data-source-independent library for Embedded Data Mining.
 * Copyright: Copyright (c) 2002 Prudential Systems Software GmbH
 * Company: ZSoft (www.zsoft.ru), Prudsys (www.prudsys.com)
 * @author Valentine Stepanenko ([e-mail])
 * @version 1.0
 */

package com.prudsys.pdm.Cwm.Relationships;


/**
 * An association defines a semantic relationship between classifiers.
 * Associations have two or more named ends. Associations with two or more ends
 * are called "n-ary" whereas associations with exactly two ends are called
 * "binary". Each end, depending
 *
 * upon its multiplicity, connects to zero or more instances of some classifier.
 *
 *
 *
 * In the metamodel, an Association is a declaration of a semantic relationship
 * between Classifiers, such as Classes. Associations must have two, and may have
 * more, association ends. Each end is connected to a Classifier; the same
 * Classifier may be
 *
 * connected to more than one association end in the same association. (Refer to
 * the ObjectModel?s Instance package, below, for a description of how
 * Associations are instantiated.)
 *
 *
 *
 * Because Associations are classifiers, they own and order their association ends
 * (which are Attributes) via the ClassifierFeature association. In addition,
 * because Associations are Classes, they can also own more traditional
 * StructuralFeatures such as Attributes. Consequently, they may act in a manner
 * similar to "association classes" described by
 *
 * some other object models.
 *
 *
 *
 * An association may represent an aggregation (i.e., a whole/part relationship).
 * In this case, the association end attached to the whole element is designated,
 * and the other association end represents the parts of the aggregation.
 *
 *
 *
 * Associations can be of three different kinds: (1) ordinary association, (2)
 * composite aggregate, and (3) shareable aggregate. Since the aggregate construct
 * can have several different meanings depending on the application area, CWM
 * gives a more precise meaning to two of these constructs (i.e., association and
 * composite aggregate) and leaves the shareable aggregate more loosely defined in
 * between. Only binary Associations can have composite or sharable aggregation
 * semantics.
 *
 *
 *
 * Composite aggregation is a strong form of aggregation which requires that a
 * part instance be included in at most one composite at a time and that the
 * composite object has sole responsibility for the disposition of its parts. This
 * means that the composite object is responsible for the creation and destruction
 * of the parts. In implementation terms, it is responsible for their memory
 * allocation. If a composite object is destroyed, it must destroy all of its
 * parts. It may remove a part and give it to another composite object, which then
 * assumes responsibility for it. If the multiplicity from a part to composite is
 * zero-to-one, the composite may remove the part and the part may assume
 * responsibility for itself, otherwise it may not live apart from a  composite.
 *
 *
 *
 * A consequence of these rules is that a composite aggregation implies
 * propagation semantics (i.e., some of the dynamic semantics of the whole is
 * propagated to its parts). For example, if the whole is copied or destroyed,
 * then so are the parts as well (because a part may belong to at most one
 * composite).
 *
 *
 *
 * A classifier on the composite end of an association may have parts that are
 * classifiers and associations. At the instance level, an instance of a part
 * element is considered "part of" the instance of a composite element. If an
 * association is part of a composite and it connects two classes that are also
 * part of the same composite, then an instance of the association will connect
 * objects that are part of the same composite object of which the instance is
 * part.
 *
 *
 *
 * A shareable aggregation denotes weak ownership (i.e., the part may be included
 * in several aggregates) and its owner may also change over time. However, the
 * semantics of a shareable aggregation does not imply deletion of the parts when
 * an aggregate
 *
 * referencing it is deleted. Both kinds of aggregations define a transitive,
 * antisymmetric relationship (i.e., the instances form a directed, non-cyclic
 * graph). Composition instances form a strict tree (or rather a forest).
 */
public class Association extends com.prudsys.pdm.Cwm.Core.Class implements org.omg.cwm.objectmodel.relationships.Association
{

   public Association()
   {

   }
}