Alecsandar STOIANOV

Legacy software

Introduction

Patterns & Antipatterns

Observer

observerPattern(Project, SubjectN, ObserverN, ConcrSubjsN,ConcrObserversN, UpdateMsN,AttDetMeths,NotifyMeth):-

observer(Observer,ObserverN,Project),

subject(Subject,SubjectN,Observer,AttDetMeths,NotifyMeth,UpdateMsN),

findall(X,concreteSubject(_,X,Subject),ConcrSubjsN),

findall(Y,concreteObserver(_,Y,Observer),ConcrObserversN).

God Class

This AntiPattern is characterized by a class diagram composed of a single complex controller class surrounded by simple data classes. The key problem here is that the majority of the responsibilities are allocated to a single class.

Results 1

Singleton Decorator Observer Strategy AdapterMe Pinot Me Pinot Me Pinot Me Pinot Me Pinot

jHotDraw 6.0b1

1 0 4 5 5 9 51 51 9 5

Java AWT 1.3

3 3 3 3 4 9 43 54 9 3

Java Swing

1.4

1 0 13 15 49 68 110 96 30 17

Java.io 1.4.2

0 0 3 4 0 13 5 3 0 4

Java.net 1.4.2

0 0 0 1 0 0 0 4 0 0

Apache Ant

1.6.2

2 1 3 4 2 5 64 53 9 13

Results 2

Data Class

Call Super Constant Interface

God Class Interface Bloat

Yoyo Problem(factor =

6)

Poltergeist

jHotDraw 6.0b1

10 72 0 13 25 4 18

Java AWT 1.3

23 34 0 23 27 0 2

Java Swing 1.4

55 223 2 86 48 16 7

Java.io 1.4.2

13 8 1 8 1 0 0

Java.net 1.4.2

9 0 1 2 0 0 0

Apache Ant 1.6.2

33 86 0 63 27 9 25

& Answers?

Questions