Service Design Patterns

Foreword by Martin Fowler xi Foreword by Ian Robinson xiii Preface xv Acknowledgments xxiii About the Author xxv Chapter 1: From Objects to Web Services 1 What Are Web Services? 2 From Local Objects to Distributed Objects 3 Why Use Web Services? 6 Web Service Considerations and Alternatives 7 Services and the Promise of Loose Coupling 9 What about SOA? 10 Summary 11 Chapter 2: Web Service API Styles 13 Introduction 13 Design Considerations for Web Service APIs 14 RPC API 18 Message API 27 Resource API 38 Chapter 3: Client-Service Interactions 51 Introduction 51 Request/Response 54 Request/Acknowledge 59 Media Type Negotiation 70 Linked Service 77 Chapter 4: Request and Response Management 83 Introduction 83 Service Controller 85 Data Transfer Object 94 Request Mapper 109 Response Mapper 122 Chapter 5: Web Service Implementation Styles 131 Introduction 131 Design Considerations for Web Service Implementation 132 Transaction Script 134 Datasource Adapter 137 Operation Script 144 Command Invoker 149 Workflow Connector 156 Chapter 6: Web Service Infrastructures 165 Introduction 165 Service Connector 168 Service Descriptor 175 Asynchronous Response Handler 184 Service Interceptor 195 Idempotent Retry 206 A Quick Review of SOA Infrastructure Patterns 220 Chapter 7: Web Service Evolution 227 Introduction 227 What Causes Breaking Changes? 228 Common Versioning Strategies 232 Single-Message Argument 234 Dataset Amendment 237 Tolerant Reader 243 Consumer-Driven Contracts 250 How the Patterns Promote or Hinder Service Evolution 264 Appendix: Reference to External Patterns 269 Glossary 277 Bibliography 297 Index 303

Robert Daigneau has more than twenty years of experience designing and implementing applications and products for a broad array of industries, from financial services, to manufacturing, to retail and travel. Rob has served in such prominent positions as Director of Architecture for Monster.com and Manager of Applications Development at Fidelity Investments. Rob has been known to speak at a conference or two.