The Application of Architectural and Design Patterns in Enterprise Systems By Seamus Kelly Dissertation submitted to Sligo Institute of Technology in partial fulfilment of the requirements for the M.Sc. in Computing September 2005 Dr. Kate O’Dubhchair Project Supervisor ACKNOWLEDGEMENTS.................................................................................................................IV ABSTRACT............................................................................................................................................ V CHAPTER 1: INTRODUCTION...................................................................................................1 1.1 Background...........................................................................................................................................1 1.1.1 Enterprise Applications................................................................................................................ 1 1.1.2 Design Patterns............................................................................................................................. 1 1.1.3 Java 2 Enterprise Edition (J2EE)..............................................................................................2 1.1.4 J2EE Technologies.......................................................................................................................2 1.2 Aim s ..........................................................................................................................................................6 1.3 What this project is n o t ............................ 7 1.4 Development and Production Environm ent...........................................................................8 1.5 Su m m a r y ............................................................................................................................................... 9 CHAPTER 2: LITERATURE REVIEW.................................................................................... II 2.1 Patterns................................................................................................................................................11 2.2 P attern Catalogues........................................................................................................................11 2.2.1 Gang o f Four Patterns......................................................... ...................................... 12 2.2.2 Sun's Core J2EE Patterns......................................................................................................... 14 2.2.3 Other Enterprise Pattern Catalogues.................................. 17 2.3 Architectures for Web Appi jcations......................................................................................18 2.3.1 JSP Model 1 Architecture....................................................................................... 19 2.3.2 Model- View-Controller Architecture......................................................................................19 2.4 Patterns and Fram ew orks........................................................................................................... 22 2.4.1 The Struts Framework.................................................................................................................22 2.4.2 JDeveloper ....................... 23 2.4.3 Oracle Application Development Framework .............. 24 2.5 M odel Driven Architecture (M DA) .................................... 27 2.5.1 What is M DA?.............................................................................................................................. 27 2.5.2 Agile MDA.....................................................................................................................................29 2.6 OptimalJ and M D A ...........................................................................................................................29 2.6.1 OptimalJ Models.......................................................................................................................... 30 2.6.2 OptimaU Patterns...................................................... 31 2.6.3 OptimalJ Application................................................ 34 2.1 JDeveloper and MDA ...................................................................................................................... 34 2.8 Archetype P atterns.........................................................................................................................35 2.8.1 Archetype Pattern Catalogue...................................................................................................35 2.8.2 Money Archetype Pattern................................... 36 2.8.3 Archetype Patterns and MDA...................................................................................................37 2.9 S u m m ary ...............................................................................................................................................38 CHAPTER 3: DEFINING THE DEMONSTRATION APPLICATION.................................39 3.1 The Problem Sta tem en t.................................................................................................................39 3.2 U se Cases.............................................................................................................................................. 40 3.3 The Entity M o del..............................................................................................................................42 3.4 Su m m a r y .................................................................... 42 CHAPTER 4: TEACHING EJBS AND PATTERNS................................................................43 4.1 EJB COMPONENTS................................................................................................................................. 43 4.1.1 Naming convention............................................................................................................ 44 4.2 Session Beans...................................................................................................................................... 44 4.2.1 Stateless Session Beans.............................................................................................................. 44 4.2.2 Remote and Local Clients............................................................................... 49 4.2.3 The EJBObject.............................................................................................................................. 50 4.2.4 The Deployment descriptor....................................................................................................... 50 4.2.5 Stateful Session Beans............................... .51 4.3 Entity Beans .......................................................... 54 4.3.1 Bean Managed Persistence (BMP) .... 54 4.3.2 Refactor with Patterns.............................. .59 4.3.3 Primary Key Block Generator Pattern.... 60 4.3.4 Data Access Object Pattern...................... .61 4.3.5 Container Managed Persistence (CMP) . .62 4.3.6 EJB Query Language (EJB QL).............. 66 4.3.7 Remote Method Calls................................ 66 4.3.8 Transfer Object Pattern............................ 68 4.3.9 Session Facade Pattern............................. .68 4.3.10 Service Locator Pattern............................ 69 4.4 Message-Driven Beans (MDBS) ....... 69 4.4.1 Service A cti vat or Pattern.......................... 70 4.5 S u m m a ry ................................................................. 70 CHAPTER 5: THE APPLICATIONS. 71 5.1 The M essage Pro d u cer...................... -.. 71 5.2 The M ain Applica tio n ........................................... 71 5.3 The M o d e l.................... ............................................ 72 5.3.1 The Message Consumer................... 72 5.3.2 Container Managed Relationships (CMRs)., 73 5.3.3 The Portfolio as a Stateful Session Bean..... 77 5.4 The Controller....................................................... 78 5.5 The Vie w ...................................................................... 80 5.5.1 Composite View pattern................................. 80 5.5.2 Value List Handler pattern............................ 81 5.6 The Wireless Clien t............................................... 81 5.7 Su m m a r y ........................................................................ 83 CHAPTER: 6 CONCLUSIONS........................... 84 6.1 A i m s .................................................................... .84 6.2 D e p l o y m e n t .................................................... .85 6.3 A r e a s o f Fu rth er R e s e a r c h .. .86 6.3.1 The Application as a Learning Tool.. .86 6.3.2 OptimaU and Archetype Patterns...... .86 6.3.3 Wireless Clients................................... .87 6.4 Su m m a r y .......................................................... .87 REFERENCES. ,88 APPENDIX A CHAPTER 4 CODE. ..91 APPENDIX B CHAPTER 5 CODE. 118 APPENDIX C CONFIGURATION FILES.... 143 APPENDIX D WIRELESS CLIENT............. 152 APPENDIX E OPTIMALJ APPLICATION.. 154 J2EE Components.................................................................. ..2 GoF Pattern Catalogue........................................................... 12 Core J2EE Pattern Catalogue ................................... 17 Simple JSP Application......................................................... 18 JSP Model 1 Architecture.....................................................