1. An Approach to Measure Java Code Quality in Reuse Environment Aline Timóteo Advisor: Silvio Meira UFPE – Federal University of Pernambuco alt.timoteo@gmail.com 1

2. Summary Motivation Background  Metrics An Approach to Measure Java Code Quality Main Contributions Status 2

3. Motivation 3

4. Motivation Reuse Benefit  Productivity  Cost  Quality  Reuse is a competitive advantage!!!!! Reuse environment [Frakes, 1994]  Process  Metrics  Tools Repository Search engine Domain tools … 4

5. Problem Component Repository promote reuse success [Griss, 1994] Artifacts quality must be assured by the organization that maintains a repository? [Seacord, 1999] How to minimize low-quality artifacts reuse? 5

6. Background 6

7. Metrics “Software metrics is a method to quantify attributes in software processes, products and projects” [Daskalantonakis, 1992] Metrics Timeline  Age 1: before 1991, where the main focus was on metrics based on the code complexity  Age 2: after 1992, where the main focus was on metrics based on the concepts of Object Oriented (OO) systems 7

8. Age 1: Complexity Age 2: Object Oriented 8

9. Most Referenced Metrics LOC Cyclomatic Complexity [McCabe, 1976] Chidamber and Kemerer Metrics [Chidamber, 1994] Lorenz and Kidd Metrics [Lorenz, 1994] MOOD Metrics [Brito, 1994] 9

10. Problems related to Metrics [Ince, 1988 and Briand, 2002] Metrics Validation  Theoretical Validation Measurement goal Experimental hypothesis Environment or context  Empirical validation Metrics Automation  Different set of metrics implemented  Bad documentation  Quality attributes x Metrics 10

11. An Approach to Measure Java Code Quality 11

12. An Approach to Measure Java Code Quality Quality Attributes x Metrics Metrics Selection and Specification Quality Attributes measurement 12

13. Quality in a Reuse Environment [Etzkorn, 2001] ISO 9126 13

14. Quality Attributes x Metrics Quality Attributes Code Attributes LOC Cyclomatic Complexity CK Metrics WMCDITNOCCBORFCLCOM sizex Analyzabilitycomplexity xxx XX documentationx complexity xxx XX modularity/ encapsulation X Changeabilitycoupling x X cohesion X inheritance x Stability Testabilitycomplexity xxx XX coupling x X complexity xxx Xx documentationx Reusability modularity/ encapsulation x coupling X x cohesion x 14

15. Metrics Selection Applicable for Java Empirical Validation Theoretical Validation Acceptance 15

16. Metrics Selection McCabe Metric [McCabe, 1976]  Theoretical Validation, according to graphos teory  Independence of technology  Empirical Validation  Acceptance [Refactorit, 2001; Metrics, 2005; JHawk, 2007] 16

17. Metrics Selection CK Metrics [Chidamber, 1994],  Theoretical Validation,  Developed in a OO context  Empirical Validation [Briand, 1994; Chidamber, 1998; Tang, 1999].  Acceptance [Refactorit, 2001; Metrics, 2005; JHawk, 2007] 17

18. Metrics Specification Response for a Class Definition Short nameRFC Description The response set of a class is a set of methods that can potentially be executed in response to a message received by an object of that class. Calculated by RFC = M + R M = number of methods in the class R = number of remote methods directly called by methods of the class Allowable valueRFC<=50 PrivateNo Analysis PresentationN/A Range of analysisWhen the development cycle is done Analysis procedureIdentify how classes have a highest responsibility ResponsibleMetrics Analyst 18

19. Quality Attributes Measurement (QAM) QAM = (the number of metrics that have a allowable value)  Heuristically QAM >= Number of metrics /2 Example: 2,5 <= QAM <= 5 Quality Attribute Code Attribute CK Metrics WMCDITCBORFCLCOM Testability complexityxx xx coupling x x Max Testability = 5 Min Testability = 2,5 19

20. Approach Automation 20

21. Approach Automation 21 Analyzability QAM = 3.0 -------> RFC: 2.0 -------> WMC 1.0 -------> CC 0.0 Changeability QAM = 3.0 -------> CBO 3.0 -------> RFC: 2.0 -------> WMC 1.0 public class Client implements Runnable, CommandListener { /** * Start the client thread */ public void start() { Thread t = new Thread(this); t.start(); } }

22. Experiment 22

23. Experiment Main Question  The retrieval component quality is better? Compare B.A.R.T. search results  Results before introduce filter  Results after introduce filter Apply questionnaire for customers 23

24. Main Contributions Introduce quality analysis in a repository  Reduce code problem propagation  Highest Reliability 24

25. Current Stage 25

26. Referências [Frakes, 1994] W. B. Frakes and S. Isoda, "Success Factors of Systematic Software Reuse," IEEE Software, vol. 11, pp. 14--19, 1994. [Griss, 1994] M. L. Griss, "Software Reuse Experience at Hewlett-Packard," presented at 16th International Conference on Software Engineering (ICSE), Sorrento, Italy, 1994. [Garcia, 2006] V. C. Garcia, D. Lucrédio, F. A. Durão, E. C. R. Santos, E. S. Almeida, R. P. M. Fortes, and S. R. L. Meira, "From Specification to Experimentation: A Software Component Search Engine Architecture," presented at The 9th International Symposium on Component-Based Software Engineering (CBSE 2006), Mälardalen University, Västerås, Sweden, 2006. [Etzkorn, 2001] Letha H. Etzkorn, William E. Hughes Jr., Carl G. Davis: Automated reusability quality analysis of OO legacy software. Information & Software Technology 43(5): 295-308 (2001) [Daskalantonakis, 1992] M. K. Daskalantonakis, “A Pratical View of Software Measurement and Implementation Experiences Within Motorola”, IEEE Transactions on Software Engineering, vol 18, 1992, pp. 998–1010. [McCabe, 1976] T. J. McCabe, “A Complexity Measure”. IEEE Transactions of Software Engineering, vol SE-2, 1976, pp. 308-320. [Chidamber, 1994] S. R. Chidamber, C. F. Kemerer, “A Metrics Suite for Object Oriented Design”, IEEE Transactions on Software Engineering, vol 20, Piscataway - USA, 1994, pp. 476-493. [Lorenz, 1994] M. Lorenz, J. Kidd, “Object-Oriented Software Metrics: A Practical Guide”, Englewood Cliffs, New Jersey - USA, 1994. [Brito, 1994] A. F. Brito, R. Carapuça, "Object-Oriented Software Engineering: Measuring and controlling the development process", 4th Interntional Conference on Software Quality, USA, 1994. [Ince, 1988] D. C. Ince, M. J. Sheppard, "System design metrics: a review and perspective", Second IEE/BCS Conference, Liverpool - UK, 1988, pp. 23-27. [Briand, 2002] L. C. Briand, S. Morasca, V. R. Basili, “An Operational Process for Goal-Driven Definition of Measures”, Software Engineering - IEEE Transactions, vol 28, 2002, pp. 1106-1125. [Morasca, 1989] S. Morasca, L. C. Briand, V. R. Basili, E. J. Weyuker, M. V. Zelkowitz, B. Kitchenham, S. Lawrence Pfleeger, N. Fenton, "Towards a framework for software measurementvalidation", Software Engineering, IEEE Transactions, vol 23, 1995, pp. 187-189. [Seacord, 1999] Robert C. Seacord. Software engineering component repositories. Technical report, Software Engineering Institute (SEI), 1999 26

27. [Refactorit, 2001] Refactorit tool, online, last update: 01/2008, available: http://www.aqris.com/display/ap/RefactorIt http://www.aqris.com/display/ap/RefactorIt [Jdepend, 2005] JDepend tool, online, last update: 03/2006,available: http://www.clarkware.com/software/JDepend.html http://www.clarkware.com/software/JDepend.html [Metrics, 2005] Metrics Eclipse Plugin, online, last update: 07/2005, available: http://sourceforge.net/projects/metrics http://sourceforge.net/projects/metrics [Jhawk, 2007] JHawk Eclipse Plugin, online, last update: 03/2007, available: http://www.virtualmachinery.com/jhawkprod.htm http://www.virtualmachinery.com/jhawkprod.htm 27

28. Aline Timóteo UFPE – Federal University of Pernambuco alt.timoteo@gmail.com 28