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Towards Clean Legacy Code

Lars Martin
Lars Martin

This document discusses approaches for modernizing legacy code. It introduces model-based software modernization using Eclipse-based tooling. The MoDisco framework allows discovering models from legacy code and transforming them. MoDisco supports understanding legacy systems through reverse engineering, documentation, refactoring, and migrating systems to new frameworks or architectures. The document demonstrates migrating a legacy testing framework from JUnit3 to JUnit4 as a practical example. Overall, MoDisco provides customizable modeling and transformation capabilities to help modernize legacy Java code.

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Towards Clean Legacy Code Lars Martin, Clean Code Days 2013, 11.09.2013
Towards Clean Legacy Code 則р Developer, Architect, Consultant 則р Java Enterprise, Eclipse, Continuous Who am I?
Agenda +introduction into model based software modernization approaches (software evolution) +introduction of Eclipse based tooling full migration of legacy systems Make sure you know what the code does before you attempt any modifications, don't just jump in. Towards Clean Legacy Code
Towards Clean Legacy Code Motivation 則р legacy system 則р heavy database access 則р ORM 竪 java.sql.* 則р new team 息 Katharina Bregulla / pixelio.de
Towards Clean Legacy Code Motivation 則р Raising Questions which tables will be accessed? will other tables (modules) be accessed? if yes, migrated already? automation possible? 息 Katharina Bregulla / pixelio.de
Towards Clean Legacy Code Horseshoe-Model PIM PSMPSM PIM Code Code ForewardEngineering(MDA) ReverseEngineering(ADM) Re-Engineering Architecture Transformation Reverse engineering: is the process of analyzing a software system to create representations of the system at a higher level of abstraction. Re-Engineering: ... is the analysis and modification of a software system to change its form and implement it in its new form. (Forward) Engineering: is the way of designing systems, starting from abstract logical and implementation independent specification to gradually lead to the implementation of a physical system. 息 unknown
Towards Clean Legacy Code MoDisco - Concepts MoDisco Eclipse Modeling Source Code Databases Metrics Norm checking Configuration Files Restruct. Code Migrated Code Documentation Impact Analysis Models Viewpoints ..other
Towards Clean Legacy Code MoDisco - Modernization Phases Models Discover Viewpoints UnderstandExisting Artifacts Software Artifacts ≒ Source Code ≒ Configuration ≒ Tests ≒ Database ≒ New Artifacts Transform
Towards Clean Legacy Code MoDisco Use Cases 息 Michael B端hrke / pixelio.de
則р Quality Assurance (Metrics, ...) 則р Documentation (Structure, Dataflow, ) 則р Refactorierung (Design Pattern, Standards, ) 則р Migration (Framework, Architecture, ) Towards Clean Legacy Code MoDisco Use Cases 息 Michael B端hrke / pixelio.de
Practical Session (1/2) Towards Clean Legacy Code
JUnit4 辿 JUnit3 息 Katharina Wieland M端lle / pixelio.de Towards Clean Legacy Code Practical Session
JUnit3 Queries JUnit3 Facet JUnit3 Customization java.ecore uses uses customizes extends conforms to Java EMF Model Towards Clean Legacy Code
Practical Session (2/2) Towards Clean Legacy Code
Abstract Factory, Adapter, Bridge, Builder, , Singleton, , Visitor 息 kiramain / pixelio.de Towards Clean Legacy Code Practical Session
Towards Clean Legacy Code Conclusion 端錫 Customizability o Metamodels o M2M, M2T 端錫 Extensive o Discoverer o Queries 端錫 Workflow 端錫 DSL (Xtext, ) 端錫 (Focus on Java) 端錫 Entry barriers 端錫 Toolset 息 Gerd Altmann / pixelio.de
息 Mario De Ma?a / pixelio.de 端錫 Metrics on software maintainability o bugs / commits per time unit o committer per time unit o 端錫 Identification of variants within branches o modularization o 端錫 Sync domain model <> DB Towards Clean Legacy Code Outlook
息 Gerd Altmann / pixelio.de
Master Thesis / Abschlussarbeit Software Engineering Aufgabengebiet: ≒ Entwicklung von Methoden zur Informationsgewinnung ≒ Implementierung der Methoden mittels Eclipse basierter Technologien Studienbereiche: ≒ Informatik und -Informatik 息 Willi Heidelbach / pixelio.de
SMB GmbH Plauenscher Ring 21 D-01187 Dresden Dipl.-Inf. Lars Martin +49-(0)173-64 24 461 lars.martin@smb-tec.com

More Related Content

Towards Clean Legacy Code

  • 1. Towards Clean Legacy Code Lars Martin, Clean Code Days 2013, 11.09.2013
  • 2. Towards Clean Legacy Code 則р Developer, Architect, Consultant 則р Java Enterprise, Eclipse, Continuous Who am I?
  • 3. Agenda +introduction into model based software modernization approaches (software evolution) +introduction of Eclipse based tooling full migration of legacy systems Make sure you know what the code does before you attempt any modifications, don't just jump in. Towards Clean Legacy Code
  • 4. Towards Clean Legacy Code Motivation 則р legacy system 則р heavy database access 則р ORM 竪 java.sql.* 則р new team 息 Katharina Bregulla / pixelio.de
  • 5. Towards Clean Legacy Code Motivation 則р Raising Questions which tables will be accessed? will other tables (modules) be accessed? if yes, migrated already? automation possible? 息 Katharina Bregulla / pixelio.de
  • 6. Towards Clean Legacy Code Horseshoe-Model PIM PSMPSM PIM Code Code ForewardEngineering(MDA) ReverseEngineering(ADM) Re-Engineering Architecture Transformation Reverse engineering: is the process of analyzing a software system to create representations of the system at a higher level of abstraction. Re-Engineering: ... is the analysis and modification of a software system to change its form and implement it in its new form. (Forward) Engineering: is the way of designing systems, starting from abstract logical and implementation independent specification to gradually lead to the implementation of a physical system. 息 unknown
  • 7. Towards Clean Legacy Code MoDisco - Concepts MoDisco Eclipse Modeling Source Code Databases Metrics Norm checking Configuration Files Restruct. Code Migrated Code Documentation Impact Analysis Models Viewpoints ..other
  • 8. Towards Clean Legacy Code MoDisco - Modernization Phases Models Discover Viewpoints UnderstandExisting Artifacts Software Artifacts ≒ Source Code ≒ Configuration ≒ Tests ≒ Database ≒ New Artifacts Transform
  • 9. Towards Clean Legacy Code MoDisco Use Cases 息 Michael B端hrke / pixelio.de
  • 10. 則р Quality Assurance (Metrics, ...) 則р Documentation (Structure, Dataflow, ) 則р Refactorierung (Design Pattern, Standards, ) 則р Migration (Framework, Architecture, ) Towards Clean Legacy Code MoDisco Use Cases 息 Michael B端hrke / pixelio.de
  • 12. JUnit4 辿 JUnit3 息 Katharina Wieland M端lle / pixelio.de Towards Clean Legacy Code Practical Session
  • 15. Abstract Factory, Adapter, Bridge, Builder, , Singleton, , Visitor 息 kiramain / pixelio.de Towards Clean Legacy Code Practical Session
  • 16. Towards Clean Legacy Code Conclusion 端錫 Customizability o Metamodels o M2M, M2T 端錫 Extensive o Discoverer o Queries 端錫 Workflow 端錫 DSL (Xtext, ) 端錫 (Focus on Java) 端錫 Entry barriers 端錫 Toolset 息 Gerd Altmann / pixelio.de
  • 17. 息 Mario De Ma?a / pixelio.de 端錫 Metrics on software maintainability o bugs / commits per time unit o committer per time unit o 端錫 Identification of variants within branches o modularization o 端錫 Sync domain model <> DB Towards Clean Legacy Code Outlook
  • 18. 息 Gerd Altmann / pixelio.de
  • 19. Master Thesis / Abschlussarbeit Software Engineering Aufgabengebiet: ≒ Entwicklung von Methoden zur Informationsgewinnung ≒ Implementierung der Methoden mittels Eclipse basierter Technologien Studienbereiche: ≒ Informatik und -Informatik 息 Willi Heidelbach / pixelio.de
  • 20. SMB GmbH Plauenscher Ring 21 D-01187 Dresden Dipl.-Inf. Lars Martin +49-(0)173-64 24 461 lars.martin@smb-tec.com