Institut für Architektur von Anwendungssystemen Universität Stuttgart Universitätsstr. 38 70569 Stuttgart Diplomarbeit Nr. 2345 UML 2.0 Profile for WS-BPEL with Mapping to WS-BPEL Thomas Ambühler Studiengang : Softwaretechnik Prüfer : Prof. Dr. Frank Leymann Betreuer : Michael Friess, IBM Deutschland Entwicklung GmbH Begonnen am : 01.05.2005 Beendet am : 31.10.2005 CR-Klassifikation : D.2.2, D.3.2, D.2.12 Abstract UML 2.0 is the de-facto standard for graphical notation and modelling in software engineering and has a wide variety of usage scenarios. The Business Process Execution Language for Web Services (BPEL4WS) is an XML-based language for specifying business processes, both abstract and executable, but does not include a graphical representation. This thesis specifies a UML 2.0 profile which enables the graphical representa- tion of BPEL processes with UML 2.0. It also details the implementation of this profile using the Rational Software Modeler and furthermore, the transformation of these UML 2.0 models to BPEL by means of transformation rules implemented as an Eclipse plug-in using a transformation engine. The results of this thesis include the specified profile and a specific implementa- tion (with some adaptations). It also includes the mapping rules and shows how they can be used to implement a mapping tool. Credits I would like to thank Prof. Dr. Frank Leymann for his support and this interesting topic. Special thanks go to Michael Friess. Without his support, experience, and input this thesis would not have been possible. I would also like to thank Tracy Gardner for her valuable input on this thesis, especially regarding UML, and Catherine Griffin for her help and support throughout the implementation. Moreover, I would like to thank my mother. Without her, I would not be where and what I am to- day. Table of Contents 1. INTRODUCTION .........................................................................................11 1.1. Motivation........................................................................................................................ 11 1.2. Scope ............................................................................................................................... 11 1.3. Structure of the Thesis .................................................................................................. 12 2. BUSINESS PROCESS EXECUTION LANGUAGE FOR WEB SERVICES 13 2.1. Service Oriented Architecture (SOA) ........................................................................... 13 2.1.1. Web Services .......................................................................................................... 15 2.1.1.1. Web Service Description Language (WSDL) .................................................. 15 2.2. Business Process Execution Language for Web Services........................................ 16 2.2.1. History of BPEL .......................................................................................................... 16 2.2.2. BPEL Technical Overview ......................................................................................... 17 2.2.2.1. Process Life Cycle and Types .......................................................................... 17 2.2.2.2. Partner Links and Communication .................................................................. 17 2.2.2.3. Data Handling, Properties and Correlation ..................................................... 18 2.2.2.4. Basic Activities .................................................................................................. 19 2.2.2.5. Structured Activities ......................................................................................... 19 2.2.2.6. Scopes and Handlers ........................................................................................ 21 2.3. BPEL 2.0 .......................................................................................................................... 22 3. UNIFIED MODELING LANGUAGE (UML)..................................................23 3.1. History of UML ................................................................................................................ 23 3.2. UML Diagrams................................................................................................................. 24 3.2.1. Structural Diagrams ............................................................................................... 24 3.2.1.1. Class Diagrams .................................................................................................. 25 3.2.1.2. Composite Structure Diagrams ........................................................................ 25 3.2.1.3. Other Structural Diagrams ................................................................................ 28 3.2.2. Behavioural Diagrams ........................................................................................... 29 3.2.2.1. Activity Diagrams .............................................................................................. 29 3.2.2.2. Other Diagrams .................................................................................................. 37 3.3. UML profiles.................................................................................................................... 39 3.4. UML 1.4 Draft Profile for BPEL 1.0................................................................................ 41 3.4.1. Dependency Management and packages ............................................................ 41 3.4.2. Data Types and Interfaces .................................................................................... 42 3.4.3. Properties and Correlations .................................................................................. 42 3.4.4. Partner Link Types ................................................................................................. 43 3.4.5. Process, State, and Ports ...................................................................................... 44 3.4.6. Data Handling ......................................................................................................... 44 3.4.7. Basic Activities ...................................................................................................... 45 3.4.8. Structured Activities .............................................................................................. 45 3.4.9. Error Handling ........................................................................................................ 46 3.4.10. Issues ...................................................................................................................... 46 3.4.11. Reusable Profile Concepts ................................................................................... 47 4. UML 2.0 PROFILE FOR BPEL 1.1 .............................................................48 4.1. Concepts adapted from previous Profile ..................................................................... 48 4.2. New Concepts................................................................................................................. 52 5. PROFILE IMPLEMENTATION ....................................................................60 5.1. Rational Software Modeler ........................................................................................ 60 5.1.1. Relevant Restrictions in Rational Software Modeler ......................................... 60 5.2. Implementation Details .................................................................................................. 61 5.3. Considerations for BPEL 2.0......................................................................................... 67 6. MAPPING BETWEEN PROFILE AND BPEL .............................................71 6.1. Relation and Transformation Rules.............................................................................. 71 6.1.1. BPEL Process ........................................................................................................ 72 6.1.2. Standard Activities and Elements for BPEL activities ....................................... 74 6.1.3. BPEL basic activities ............................................................................................. 75 6.1.4. BPEL Structured Activities ................................................................................... 78 6.1.5. WSDL/XSD elements ............................................................................................. 81 6.1.6. Approach to Overall Mapping ............................................................................... 82 6.2. Transformation Technologies....................................................................................... 85 6.3. Realisation of Prototype ................................................................................................ 87 7. CONCLUSION.............................................................................................90 7.1. Future Work..................................................................................................................... 90 LIST OF LITERATURE ......................................................................................91 APPENDIX A - UML 2.0 PROFILE FOR BPEL.............................................. A - 1 Table of Figures FIGURE 1: SOA COMPONENTS (FROM [21]) ....................................................................................... 14 FIGURE 2: WSDL INFORMATION MODEL ...........................................................................................