Sanierung grosser Software Systeme - UZH00000000-0476-116c... · Sanierung grosser ! Software...
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Sanierung grosser Software Systeme Sibylle Peter, Dr. Dieter Holz Canoo Engineering AG Basel, Switzerland
Transcript of Sanierung grosser Software Systeme - UZH00000000-0476-116c... · Sanierung grosser ! Software...
Sanierung grosser !Software Systeme!Sibylle Peter, Dr. Dieter Holz!Canoo Engineering AG!Basel, Switzerland!
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Sibylle Peter Dieter Holz
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Inhalt
๏ Einführung
๏ Die Fallstudie: Investionsberatung für Kundenberater
๏ Die Sanierung
๏ Wie wir arbeiten
๏ Wie wird ein Sanierungsprojekt ein Erfolg?
Einführung
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Sanierungsprojekte
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Sanierungsprojekte
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Definition (Martin Fowler, Refactoring, pg. 53):
Refactoring (noun): a change made to the internal structure of software to make it easier to understand and cheaper to modify without changing its observable behavior.
Refactor (verb): To restructure software by applying a series of refactorings without changing it‘s observable behavior
Sanierung durch Refactoring
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Software Entropie
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Software Entropie
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Software Entropie
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Die Fallstudie
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Facts
๏ Produktiv und erfolgreich seit 2004
๏ Kontinuierlich weiterentwickelt
๏ 320 JSP Dateien, 1800 Klassen
๏ Ca 70. funktionale Tests
๏ Wenig Unit Tests
๏ Wenig Dokumentation
๏ Hohe Fluktation, hohe Kosten, Change Requests können nicht mehr implementiert werden.
Start: Erste Analyse
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Abhängigkeiten
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Objekttypen
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Action
Java Beans
JSP
ServiceInvoker
Service
Worker
Controller Helper
Mapper
Container
HttpServlet
BusinessObject
HttpServlet
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Masterplan
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Action
Java Beans
JSP
Container
HttpServlet
BusinessObject
Facade TransferObject
HttpServlet
Util
Service Mapper
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Masterplan
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Java Beans
Service Mapper
Validator
Facade TransferObject
Action
JSP HttpServlet
Formatter
Aggregating Facade
Refactoring Teil 1
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Ziel: Neues Service Layer
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1. Schritt Strukturierung in Fassaden
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2. Schritt: Einführung von Transfer Objekten (TO)
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Presentation!Layer!
transfer objects!
JSP Java Bean Action HttpRequest
BusinessObject Converter
TransferObject
Facade
Service
Service!Layer!
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public class User extends CoreObject { private String id; private Employee userIdentity; private RoleBUManager m_roleBUManager = new RoleBUManager(); private boolean isAllowed = false; private String eMailTask; private Timestamp mutTimestamp; private String mutId;
public final class UserTO { private final String fId; private final String fEamCode; private final String fBuCode; private final String fDepartment;
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Presentation!Layer!JSP Java Bean Action HttpRequest
BusinessObject Converter
TransferObject Service!Layer!
ServiceObject
EJB Proxy
simple!
complex!
1:1!
1:n! Mapper
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Presentation!Layer!JSP Java Bean Action HttpRequest
BusinessObject Converter
TransferObject Service!Layer!
ServiceObject
EJB Proxy
simple!
complex!
structural logic m:n!
1:1! Mapper
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Validierung
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public final class AARefCurrencyTO { ... public AARefCurrencyTO(UID<AARefCurrencyTO2> uid, String eamCode, final BigDecimal manual, BUCode buCode, MutSeqNr mutSeqNr, BigDecimal sortOrder, Long language, String name) { // Preconditions: if (uid == null) throw new IllegalArgumentException(...); ... if (language > 4) throw new IllegalArgumentException(...);
// Assignments: this.uid = uid; ... }
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Fassaden Interface
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public static FrontpageText getFrontpageText (CriteriaToGetFrontpageText criteria)
throws CoreException
public CriteriaToGetFrontpageText(String buCode, User user, int entryFrom)
public static FrontpageTextTO getFrontpageText (String buCode, UserTO user)
throws CoreException
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3. Schritt: Neues Service Layer
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inTO! outTO!
Service!
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Service Interface und AbstractService
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public interface IService<TOI, TOO> { public TOO execute(TOI toi) throws CoreException; }
public abstract class AbstractService<TOI, SOI, SOO, TOO> implements IService<TOI, TOO> { public final TOO execute(final TOI toi)
throws CoreException { if (toi == null) { throw new IllegalArgumentException(“'toi' must not
be null"); } SOI soi = mapInput(toi); SOO soo = innerExecute(soi); return mapOutput(soo); }
protected abstract SOI mapInput(TOI toi); protected abstract SOO innerExecute(SOI soi)
throws CoreException; protected abstract TOO mapOutput(SOO soo); }
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Aggregierende Service Klassen
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inTO! outTO!
Services!
inTO A! outTO A!
Service A!
Service!
inTO B! outTO B!
Service B!
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4. Schritt: Einführung von Basis Typen
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// Usage example: BUCode buCode = BUCode.getFlyweight("0012");
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Fassaden Interface
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public static FrontpageTextTO getFrontpageText(BUCode buCode, EAMCode eamCode, UserTO user) throws CoreException
public static FrontpageTextTO getFrontpageText(String buCode, String eamCode, UserTO user) throws CoreException
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Resultat nach Teil 1
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Old Presentationlayer
Converter
New Servicelayer Architecture!
Design Guidelines for - Services
- TransferObjects - Basetypes
New Feature:!
RiskAnalyzer!
Change Request:!CoSa!
Refactoring von Komponenten
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Current State
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New Servicelayer Architecture!
New Business Layer
Old Presentationlayer
Converter Presentation Layer
Domain Layer
Refactored Components New Features
Old GUI Framework
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Domain Model Adapters
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public class MonitoredHoldingDO extends AbstractHoldingDO implements IMonitoredHoldingDO {
public MonitoredHoldingDO(final Holding holding) { super(holding); }
@Override protected BOInfo getBOInfo() { return new BOInfo(getHolding().getWorkingTIS(), getAssetsFromHolding (), getSafekeepingAccountsFromHolding()); }
private ImmutableMap<Integer, Asset> getAssetsFromHolding() { return HoldingDOBuilderUtil.getTisIncludedAssetsFromHolding
(getHolding(), getHolding().getWorkingTIS()); } … }
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Komponente Load Partner
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Vorgehen
๏ Code aufräumen ‣ IDE Vorschläge umsetzen (Remove unused code etc)
๏ Überschaubare Einheiten erstellen ‣ Mit Extract Method Refactoring Methoden herausziehen ‣ Abhängigkeiten zu Attributen entfernen (static methods) ‣ Move Refactoring benutzen, um diese Methoden in einer Hilfklasse
zwischenzulagern
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Vorgehen
๏ Analyse der neuen Einheiten und Design gemäss der Zielarchitektur
๏ Akzeptanz Tests definieren und mit BBD Frameworks implementieren
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Akzeptanztest
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scenario "DictionaryService can find the word 'Griffon'", { given "an instance of DictionaryService is available", { service = new DictionaryService() }
when "the word 'Griffon' is used as parameter", { result = service.findDefinition('Griffon') }
then "the definition should be found", { assert result == "Grails inspired desktop application development platform.” } }
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Akzeptanztest mit EasyB
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Vorgehen
๏ Refactoring ‣ Wenn noch nötig, Mikado Methode anwenden
๏ Messen der Code Qualität
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Sonar Dashboard
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Voraussetzungen für erfolgreiche Sanierungsprojekte?
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Wie wir arbeiten
Daily standup meeting!
Regular workshops with the customer‘s lead engineer!
Retrospective in regular
intervalls!
Lightweigth, but intensive testing process with test
team
Monthly meeting with the project manager of the
customer
Weekly reporting with the lead engineer and
architect of the customer
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Team
Experienced, dedicated developers
motivation
A disciplined approach
team size.
A lead engineer of the customers
side
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Authorität und Flexibilität
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Management support
Accepted by the team
The customers trust Flexible,
iterative planning
Involved in system design
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Weitere Voraussetzungen
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Continuous Integration
Assessment Master Plan
Automated Integration
Tests
Good Analysis Tools
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Erkenntnisse oder Best Practices
๏ Entweder technisches oder logisches Refactoring
๏ Analyse – Implementierung – Stabilisation
๏ Früher Wissenstransfer zum Core Team
๏ Investition in automatische Regressionstest
๏ Abhängigkeiten zu anderen Systemen reduzieren
๏ Automatische Qualitätssicherung
๏ Manuelles Testing braucht Zeit – genügend Zeit einplanen
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Nachhaltigkeit
๏ Code verbessern ist nicht genug
๏ Professionelle Ethik einführen
๏ Technische Schulden überwachen und ggf. beseitigen
๏ Continous Improvement: Retrospektiven
๏ Core Team muss unterstützt werden, damit neue Funktionalität in guter Qualität ausgeliefert wird.
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Warum Sanierungsprojekte?
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Bücher und Links
๏ Martin Fowler, Refactoring: Improving the Design of Existing Code
๏ Stephan Ducasse, Oscar Nierstrasz, Object Oriented Reengineering Patterns PDF: http://www.win.ua.ac.be/~sdemey/
๏ Joshua Kerievsky, Refactoring to Patterns
๏ Martin Lippert, Stefan Rook, Refactoring in Large Software Projects
๏ Behaviour Driven Development: ‣ EasyB: http://www.easyb.org/ ‣ Spock: http://code.google.com/p/spock/
๏ Sonar: http://www.sonarsource.org/
๏ Mikado Method: http://pragprog.com/magazines/2010-06/the-mikado-method
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Master Thesis @ Canoo
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Master Thesis @ Canoo
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