MDT/UML2/UML2 4.0 Migration Guide
Copyright © 2011 CEA
The intent of this guide is to assist consumers in the process of migrating from the UML2 3.x API, based on the UML 2.2 specification, to the new UML2 4.0 API, based on the UML 2.4 specification, and to summarize any new features of the implementation that developers may want to take advantage of.
Last Updated: October 18, 2011
The Eclipse UML2 (Unified Modeling Language 2.x) project is an EMF-based implementation of the UML 2.x metamodel for the Eclipse platform. This implementation was previously compliant with the 2.2 version of the UML specification, for which newer versions, namely 2.3 and 2.4 (and soon, 2.4.1), have been released by the Object Management Group (OMG) over the past couple of years. The source code for the UML2 project used to be stored in a CVS repository and its installable artifacts (update sites and downloads) were produced using an unsupported pre-Athena build system running on a machine that was at risk of being decommissioned in the near future.
The UML2 metamodel implementation has been enhanced so that it is compliant with the 2.4 and, implicitly, 2.3 version of the UML specification. This enhanced implementation has been delivered as a new version, 4.0, of the UML2 project, to be released as part of the Juno simultaneous release of Eclipse. The source code for this new version of the project is managed in an Eclipse git repository and built, using Buckminster, on the Hudson installation at Eclipse.
UML 2.4 was actually released by the OMG as part of a series of revisions, also known as the “2.4 series”, which includes updated versions of the Meta Object Facility (MOF) and MOF 2 XMI Mapping specifications as well. Based on a careful analysis of the delta between the previous UML2 implementation and the UML 2.4 and 2.3 specifications, described in more detail below, it was decided that the new version of UML2 would NOT be compatible with UML2 3.x. UML2 4.0 supersedes previous version(s) of the project (i.e., new major or minor versions of the 3.x stream will NOT be released) and is neither API contract nor binary compatible with UML2 3.x.
This migration guide has been provided to assist consumers in the process of migrating to the new UML2 4.0 API. An XMI-based (de)serialization mechanism (described herein) has also been provided to automatically migrate resources based on the UML2 3.x schema to the new 4.0 schema.
The changes in UML2 4.0 can be broken into functional areas, relating to various aspects of the EMF-based UML implementation provided by the UML2 project. The following sections describe each of these areas in detail.
The UML2 project provides a Java API that is generated using a (customized version of) the code generation facility in EMF. In the past, this API has been generated from a source model produced by merging models of Infrastructure, Superstructure, and L3 compliance level of UML with custom extensions introduced by the UML2 project. As of UML 2.4, however, a reference model of the merged L3 compliance level of UML, serialized in UML format, has been provided along with the specification by the OMG. As a result, the API is now generated from a source model produced by merging this merged L3 reference model with custom extensions introduced by the UML2 project.
The following subsections describe the changes to the classifiers, properties, operations, and constraints in the revised UML specifications which affected the API provided by UML2. It is worth noting that a number of the utilities and unit tests provided by UML2 were also modified in response to changes in the API.
Classifiers in UML are represented as Java interfaces, implementation classes, and enumerations in the UML2 API. These types are generated using the (customized) EMF code generator, along with associated factory and utility methods.
The following table lists the classifiers that were removed by the revised specifications. Removals that had a nontrivial impact on API compatibility and/or migration of legacy resources are highlighted in italics.
The following table lists the classifiers that were modified by the revised specifications. Modifications that had a nontrivial impact on API compatibility and/or migration of legacy resources are highlighted in italics.
The following table lists the classifiers that were added by the revised specifications. Additions that had a nontrivial impact on functionality provided by the UML2 project are highlighted in italics.