Practical software development using UML and Java Second edition
Object-Oriented Software Engineering Practical software development using UML and Java Second edition Lethbridge.book Page i Tuesday, November 16, 2004 12:22 PM Lethbridge.book Page ii Tuesday, November 16, 2004 12:22 PM Object-Oriented Software Engineering Practical Software Development using UML and Java Second edition Timothy C. Lethbridge Robert Laganière London • Burr Ridge, IL • New York • St. Louis • San Francisco •Auckland Bogotá • Caracas • Lisbon • Madrid • Mexico • Milan • Montreal • New Delhi Panama • Paris• San Juan • São Paulo • Singapore •Tokyo • Toronto Lethbridge.book Page iii Tuesday, November 16, 2004 12:22 PM Object-Oriented Software Engineering Timothy C Lethbridge Robert Laganière ISBN 0-07-70109082 Published by McGraw-Hill Education Shoppenhangers Road Maidenhead Berkshire SL62QL Telephone: 44 (0) 1628 502 500 Fax: 44 (0) 1628 770 224 Website: http://www.mcgraw-hill.co.uk British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloguing in Publication Data The Library of Congress data for this book has been applied for from the Library of Congress Publishing Director: Catriona King Development Editor: Karen Mosman Marketing Manager: Alice Duijser Senior Production Manager: Max Elvey Text Design by Mike Cotterell Cover design by Ego Creative Typeset at Neuadd Bwll, Llanwrtyd Wells Printed and bound in the UK by Bell & Bain Ltd, Glasgow Published by McGraw-Hill Education (UK) Limited an imprint of The McGraw-Hill Companies, Inc., 1221 Avenue of the Americas, New York, NY 10020. Copyright © 2005 by McGraw-Hill Education (UK) Limited. All rights reserved. No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written consent of The McGraw-Hill Companies, Inc., including, but not limited to, in any network or other electronic storage or transmission, or broadcast for distance learning. ISBN 0-07-70109082 © 2005. Exclusive rights by The McGraw-Hill Companies, Inc. for manufacture and export. This book cannot be re-exported from the country to which it is sold by McGraw-Hill. Lethbridge.book Page iv Tuesday, November 16, 2004 12:22 PM i Contents Foreword xi Preface xv Guided tour xxii Technology to enhance learning and teaching xxiv 1 Software and software engineering 1 1.1 The nature of software 1 1.2 What is software engineering? 6 1.3 Software engineering as a branch of the engineering profession 8 1.4 Stakeholders in software engineering 10 1.5 Software quality 11 1.6 Software engineering projects 14 1.7 Activities common to software projects 16 1.8 The themes emphasized in this book 20 1.9 Difficulties and risks in software engineering as a whole 24 1.10 Summary 26 1.11 For more information 26 2 Review of object orientation 29 2.1 What is object orientation? 29 2.2 Classes and objects 31 2.3 Instance variables 36 2.4 Methods, operations and polymorphism 38 2.5 Organizing classes into inheritance hierarchies 39 2.6 The effect of inheritance hierarchies on polymorphism and variable declarations 45 2.7 Concepts that define object orientation 52 2.8 A program for manipulating postal codes 55 2.9 Classes for representing geometric points 57 2.10 Measuring the quality and complexity of a program 60 2.11 Difficulties and risks in programming language choice and OO programming 62 2.12 Summary 63 2.13 For more information 63 Lethbridge.book Page v Tuesday, November 16, 2004 12:22 PM vi Contents 3 Basing software development on reusable technology 67 3.1 Reuse: building on the work and experience of others 68 3.2 Incorporating reusability and reuse into software engineering 69 3.3 Frameworks: reusable subsystems 71 3.4 The client–server architecture 77 3.5 Technology needed to build client–server systems 87 3.6 The Object Client–Server Framework (OCSF) 91 3.7 Basic description of OCSF – client side 92 3.8 Basic description of OCSF – server side 95 3.9 An instant messaging application using the OCSF 99 3.10 Difficulties and risks when considering reusable technology and client–server systems 101 3.11 Summary 102 3.12 For more information 103 4 Developing requirements 109 4.1 Domain analysis 109 4.2 The starting point for software projects 114 4.3 Defining the problem and the scope 115 4.4 What is a requirement? 119 4.5 Types of requirements 119 4.6 Use cases: describing how the user will use the system 127 4.7 Some techniques for gathering requirements 138 4.8 Types of requirements document 145 4.9 Reviewing requirements 148 4.10 Managing changing requirements 155 4.11 GPS-based Automobile Navigation Assistant (GANA) 156 4.12 Requirements for a feature of the SimpleChat instant messaging program 160 4.13 Difficulties and risks in domain and requirements analysis 164 4.14 Summary 165 4.15 For more information 166 5 Modeling with classes 169 5.1 What is UML? 169 5.2 Essentials of UML class diagrams 172 5.3 Associations and multiplicity 173 5.4 Generalization 182 5.5 Object diagrams 186 5.6 More advanced features of class diagrams 188 5.7 The basics of Object Constraint Language (OCL) 193 5.8 A class diagram for genealogy 196 5.9 The process of developing class diagrams 199 5.10 Implementing class diagrams in Java 216 5.11 Difficulties and risks when creating class diagrams 218 5.12 Summary 218 5.13 For more information 219 Lethbridge.book Page vi Tuesday, November 16, 2004 12:22 PM vii Contents 6 Using design patterns 221 6.1 Introduction to patterns 221 6.2 The Abstraction–Occurrence pattern 223 6.3 The General Hierarchy pattern 226 6.4 The Player–Role pattern 228 6.5 The Singleton pattern 231 6.6 The Observer pattern 232 6.7 The Delegation pattern 234 6.8 The Adapter pattern 236 6.9 The Façade pattern 238 6.10 The Immutable pattern 239 6.11 The Read-Only Interface pattern 240 6.12 The Proxy pattern 241 6.13 The Factory pattern 243 6.14 Enhancing OCSF to employ additional design patterns 246 6.15 Difficulties and risks when using design patterns 250 6.16 Summary 251 6.17 For more information 251 7 Focusing on users and their tasks 253 7.1 User-centered design 254 7.2 Characteristics of users 256 7.3 The basics of user interface design 258 7.4 Usability principles 262 7.5 Evaluating user interfaces 273 7.6 Implementing a simple GUI in Java 276 7.7 Difficulties and risks in user-centered design 280 7.8 Summary 280 7.9 For more information 281 8 Modeling interactions and behavior 285 8.1 Interaction diagrams 285 8.2 State diagrams 292 8.3 Activity diagrams 301 8.4 Implementing classes based on interaction and state diagrams 302 8.5 Difficulties and risks in modeling interactions and behavior 306 8.6 Summary 307 8.7 For more information 307 9 Architecting and designing software 309 9.1 The process of design 310 9.2 Principles leading to good design 314 Design Principle 1: Divide and conquer 314 Design Principle 2: Increase cohesion where possible 315 Design Principle 3: Reduce coupling where possible 321 Design Principle 4: Keep the level of abstraction as high as possible 329 Lethbridge.book Page vii Tuesday, November 16, 2004 12:22 PM viii Contents Design Principle 5: Increase reusability where possible 330 Design Principle 6: Reuse existing designs and code where possible 331 Design Principle 7: Design for flexibility 331 Design Principle 8: Anticipate obsolescence 332 Design Principle 9: Design for portability 333 Design Principle 10: Design for testability 334 Design Principle 11: Design defensively 334 9.3 Techniques for making good design decisions 336 9.4 Model Driven Development 340 9.5 Software architecture 342 9.6 Architectural patterns 347 The Multi-Layer architectural pattern 347 The Client–Server and other distributed architectural patterns 349 The Broker architectural pattern 351 The Transaction Processing architectural pattern 352 The Pipe-and-Filter architectural pattern 353 The Model–View–Controller (MVC) architectural pattern 355 The Service-Oriented architectural pattern 358 The Message-Oriented architectural pattern 360 9.7 Writing a good design document 362 9.8 Design of a feature for the SimpleChat instant messaging application 365 9.9 Difficulties and risks in design 366 9.10 Summary 367 9.11 For more information 368 10 Testing and inspecting to ensure high quality 371 10.1 Basic definitions 371 10.2 Effective and efficient testing 373 10.3 Defects in ordinary algorithms 380 10.4 Defects in numerical algorithms 388 10.5 Defects in timing and co-ordination: deadlocks, livelocks and critical races 391 10.6 Defects in handling stress and unusual situations 394 10.7 Documentation defects 398 10.8 Writing formal test cases and test plans 398 10.9 Strategies for testing large systems 402 10.10 Inspections 409 10.11 Quality assurance in general 413 10.12 Test cases for phase 2 of the SimpleChat instant messaging system 416 10.13 Difficulties and risks in quality assurance 420 10.14 Summary 421 10.15 For more information 422 11 Managing the software process 425 11.1 What is project management? 425 11.2 Software process models 428 Lethbridge.book Page viii Tuesday, November 16, 2004 12:22 PM ix Contents 11.3 Cost estimation 435 11.4 Building software engineering teams 445 11.5 Project scheduling and tracking 449 11.6 Contents of a project plan 452 11.7 Difficulties and risks in project management 453 11.8 Summary 455 11.9 For more information 456 12 Review 459 12.1 Theme 1: Understanding the customer and user 459 12.2 Theme 2: Basing development on solid principles and reusable technology 459 12.3 Theme 3: Object orientation 464 12.4 Theme 4: Visual modeling using UML 464 12.5 Theme 5: Evaluation of alternatives in requirements and design 465 12.6 Theme 6: Incorporating quantitative and logical thinking 465 12.7 Theme 7: Iterative and agile development 466 12.8 Theme 8: Communicating effectively using documentation 467 12.9 Theme 9: Risk management in all software engineering activities 467 12.10 Where next? 469 Appendix A: Summary of the UML notation used in this book 471 Appendix B: Summary of the documentation types recommended in this book 475 Appendix C: System descriptions 479 Glossary 485 Lethbridge.book Page ix Tuesday, November 16, 2004 12:22 PM Lethbridge.book Page x Tuesday, November 16, 2004 12:22 PM . xxiv 1 Software and software engineering 1 1.1 The nature of software 1 1.2 What is software engineering? 6 1.3 Software engineering as a branch of the engineering. 1.4 Stakeholders in software engineering 10 1.5 Software quality 11 1.6 Software engineering projects 14 1.7 Activities common to software projects 16