Web services are gaining importance because of their flexibility and interoperability. In this book, Daigneau provides an interesting overview of Web services (WS) and the patterns most frequently used to implement them. There are other books that cover this topic, but this one differs from the others in the way the topics and patterns are presented, organized, and analyzed.

This is a book for software developers and architects interested in WS. There is a clear need for some background on patterns and software development, but, in general, the main ideas of the book can be understood without an extensive background.

The organization is very clear and structured. Each chapter considers a specific area, proposes several patterns to tackle the problems in that area, analyzes the pros and cons of each proposal, and provides some examples of codes. Although I feel that this style of organization is a bit boring, it is practical and useful. Readers might consider this book a good reference for WS design.

The book is structured in seven chapters. Chapter 1 is a brief introduction to the topic and provides context. Basic concepts such as service and Web service are defined, and a quick reminder about older techniques such as object-oriented programming (OOP) and components is provided.

Chapter 2 analyzes three common application programming interface (API) design styles for WS: remote procedure call (RPC) API, message API, and resource API. The pros and cons of each approach are summarized, and several examples of code are provided. In addition, an interesting overview about the relation of the resource API and the principles of representational state transfer (REST) is provided.

Chapter 3 is devoted to the analysis of several design patterns for the interaction between clients and servers. After a very brief introduction to the client-server model, four patterns are discussed: request and response, request and ACK, media type negotiation, and linked service.

Chapter 4 considers four patterns used in the service layer to manage requests and responses: service controller, data transfer object, request mapper, and response mapper.

Chapter 5 elaborates on the different implementation styles that can be applied to the development of WS. Depending on the complexity and purpose of the WS, several patterns are available: the transaction script, data source adapter, operation script, command invoker, and workflow connector.

Chapter 6 discusses five common patterns of service infrastructure: the service connector, service descriptor, asynchronous response handler, service interceptor, and idempotent retry. In addition, a brief review of the most frequently used patterns for corporate service-oriented architecture (SOA) infrastructure is provided.

Chapter 7 focuses on backward and forward compatibility. The causes for the so-called breaking changes are described, and four patterns aimed at supporting WS evolution are studied: single-message argument, dataset amendment, tolerant reader, and consumer-driven contracts.

All in all, this is a well-written and well-edited book. The author has clearly been influenced by Fowler [1]--which, in fact, is a great influence.